Pesticide-Induced Diseases: Body Burden

Most people are unaware that they carry chemical compounds in their bodies. Chemical 'Body Burden' refers to the accumulation of synthetic chemicals found in pesticides, cosmetics, industrial solvents, heavy metals, etc in our bodies. At any given time, hundreds of chemicals can be found in blood, urine, breast milk and even umbilical cord blood. Many of these chemicals enter our bodies through the foods we eat or drink, products we put on our skin and air we breathe. Before birth, people normally carry a body burden inherited from their mothers. Scientists believe the typical human being hosts close to 500 chemicals in various compartments in the body, mostly in fatty tissue. Many chemicals are broken down in our bodies and their metabolites are eliminated, but others linger in our bodies for a lifetime and can increase our risk for certain diseases such as cancer and Parkinson's disease.

Over the past decade agencies like the Center for Disease Control and Prevention (CDC) have been tracking chemical burden in the general public by analyzing blood and urine. Termed “biomonitoring,” it is considered to be the most health-relevant assessment of exposure because they “measure the amount of the chemical that actually gets into people, not the amount that may get into people.” Since 2001, CDC releases its “National Report on Human Exposure to Environmental Chemicals” which documents the environmental chemical exposure in the U.S. population.

Breast Milk

• Long-term biomonitoring of polychlorinated biphenyls and organochlorine pesticides in human milk from mothers living in northern Germany
  Polychlorinated biphenyls (PCBs) and organochlorine pesticides are persistent organic pollutants that have a widespread distribution in the environment. Human biomonitoring is a suitable tool to assess the burden of humans with these substances. Over a time span of 8 years, a free analysis of their milk was offered to lactating mothers residing in the state of Lower Saxony, Germany. The human milk was analyzed for a number of organic chemicals including polychlorinated biphenyls (PCBs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), hexachlorobenzene (HCB) and ß-hexachlorocyclohexane (ß-HCH). Factors that may influence these levels were investigated using a questionnaire. In total, 4314 samples were collected in the years 1999–2006 and analyzed for their content of these persistent organic pollutants (POPs). A clear downward trend of median total PCB, DDT, ß-HCH and HCB values in all participants and also in different selected subgroups could be observed. There were reductions between 40.9% and 47.1% compared to the year 1999. Among other influencing factors, median concentrations of total PCB, DDT, ß-HCH and HCB showed a clear rise with increasing age of mothers whereas an increasing number of breastfed infants per mother led to a decrease. We conclude that the known declining trend of important xenobiotic substances in human milk of German mothers has continued.
  [Zietz, B.P., et al. 2008. International Journal of Hygiene and Environmental Health 211(5-6): 624-638]
• From mother to child: Investigation of prenatal and postnatal exposure to persistent bioaccumulating toxicants using breast milk and placenta biomonitoring
  The exposure levels of placenta and paired breast milk samples to selected organochlorine compounds and pesticides from Danish and Finnish samples have been investigated. p,p'-DDE is the dominant pollutant, ß-HCH, hexachlorobenzene, endosulfan-I, dieldrin, oxychlordane, cis-heptachlor epoxide and p,p'-DDT being the other major constituents. Their concentrations are linearly correlated between milk and placenta in similar patterns for Danish and Finnish samples. Milk samples have higher levels of these pollutants than placenta on lipid base. However, the apparently not correlated compounds, such as a-HCH, pentachlorobenzene, pentachloroanisole and methoxychlor, are generally accumulated more in placenta, which may suggest a tissue specific metabolic activity. Thus, depending on the compound of interest, biomonitoring may be done in placenta only or in both matrices.
  [Shen, H., et al. 2007. Chemosphere67(9): S256-S262]
• Risk assessment of triclosan [Irgasan] in human breast milk.
  Sixty two unselected samples of human milk from Breast Milk Banks in California and Texas have been analysed for triclosan; the concentration ranged from 0 to 2100 microg/kg lipid. A risk assessment of triclosan in human milk has been made, based on a conservative calculation of exposure of neonates and experimental toxicity test results. The maximum exposure of babies via breast milk calculated using very conservative additive assumptions is approximately 7.4 microg/kg/d. The 'Margin of Exposure' between the NOAEL and that calculated in breast fed babies is approximately 6760-fold. It is concluded that there is no evidence to indicate that the presence of a miniscule amount of triclosan in breast milk presents a risk to babies.
  [Dayan AD. 2007. Food Chem Toxicol. 45(1):125-9]
• Persistent Pesticides in Human Breast Milk and Cryptorchidism
  Prenatal exposure to some pesticides can adversely affect male reproductive health in animals. Study investigated a possible human association between maternal exposure to 27 organochlorine compounds used as pesticides and cryptorchidism among male children. 62 milk samples from mothers of cryptorchid boys and 68 from mothers of healthy boys were selected. Eight organochlorine pesticides were measurable in all samples for cases/controls: p,p'-DDE, ß-HCH, HCB, a –endosulfan, oxychlordane, p,p'-DDT, dieldrin, cis-HE. Seventeen of 21 organochlorine pesticides were measured in higher median concentrations in case milk than in control milk. Apart from trans-chlordane, there were no significant differences between cryptorchid and healthy boys for individual chemicals. However, combined statistical analysis of the eight most abundant persistent pesticides showed that pesticide levels in breast milk were significantly higher in boys with cryptorchidism. The association between congenital cryptorchidism and some persistent pesticides in breast milk as a proxy for maternal exposure suggests that testicular descent in the fetus may be adversely affected.
  [[Damgaard, I et al. 2006. Environ Health Perspect; 114(7): 1133–1138]
• Environmental Contaminants in Breast Milk
  Toxic environmental contaminants can be transferred from mother to infant via breastfeeding. Persistent organic pollutants (POPs) are a family of lipophilic stable chemicals that bioaccumulate in adipose tissue and create a lasting toxic body burden. Breastfeeding provides a significant source of exposure to POPs early in human life, the effects of which are unknown, and is the subject of a growing body of research. Despite the possibility of harm from environmental contaminants in breast milk, breastfeeding is still recommended as the best infant feeding method. This article reviews what is known about POPs in breast milk and their effect on infant development to inform clinicians about the issue, provide recommendations for practice, and promote environmental and public health policies that reduce human exposure to harmful pollutants.
  [Nickerson, K. 2006. Journal of Midwifery & Women’s Health, 51(1):26–34]
• Human Breast Milk and Xenoestrogen Exposure: A Possible Impact on Human Health
  Human milk is the best natural and optimal food for neonates with several immunologic, developmental and practical advantages throughout childhood. Although the World Health Organization strongly supports breastfeeding, it recognizes the potential health risks posed by the presence of environmental toxicants in breast milk. Contamination of human milk is widespread and due to decades of inadequately controlled pollution by toxicants, persistent pesticides or chemical solvents. These chemicals tend to degrade slowly in the environment, to bioaccumulate in the food chain and to have long half-lives in humans. Many of these environmental pollutants have estrogen-like activities and, thus they are called environmental estrogen disruptors or xenoestrogens. Certain adverse health and reproductive outcomes are attributed to these chemicals in laboratory animals and in wildlife as well as in humans. Here, authors review available data from breast milk monitoring studies suggesting the environmental chemicals that may affect child health through breastfeeding.
  [Massart, F, Harrell, J,C., Federico, G. and Saggese, G.2005. Journal of Perinatology, 25: 282–288]
• Chemical contaminants in breast milk: time trends and regional variability
  In this paper the authors review available data on levels of organochlorine pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), polybrominated diphenyl ethers (PBDEs), metals, and solvents in breast milk. Over the past few decades, levels of the organochlorine pesticides, PCBs, and dioxins have declined in breast milk in countries where these chemicals have been banned or otherwise regulated. In contrast, the levels of PBDEs are rising. Diet is a major factor that influences breast milk levels of persistent organic pollutants, with patterns in fish consumption playing a particularly significant role. Authors conclude, improved global breast milk monitoring programs would allow for more consistent data on trends over time, detection of new xenobiotics in breast milk, and identification of disproportionately exposed populations.
  [Solomon GM, Weiss PM. 2002. Environ Health Perspect.;110(6):A339-47]
• Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden.
  High levels of the commonly used, effective bactericide triclosan was found in three out of five randomly selected human milk samples. It was also found in the bile of fish exposed to municipal wastewater and in wild living fish from the receiving waters of the three wastewater treatment plants.
  [Adolfsson-Erici M, Pettersson M, Parkkonen J, Sturve J. 2002. Chemosphere. 46(9-10):1485-9]
• Pesticides and breast cancer risk: a review of DDT, DDE, and dieldrin.
  There has been interest in evaluating what role environmental chemicals, especially those with evidence of being hormonally active agents, play in breast cancer risk. Organochlorine pesticides have received the most attention because of their persistence in the environment, ability to concentrate up the food chain, continued detection in the food supply and breast milk, and ability to be stored in the adipose tissue of animals and humans. Although several early descriptive studies and a cohort study identified a strong positive association with breast cancer risk and adipose or blood levels of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and/or its metabolite dichlorodiphenyldichloroethylene (DDE), most of the more recent case--control and nested case--control studies have not supported this association. In this review author discusses these findings and explores how exposure to different forms of DDT with varying estrogenicities may have affected the results of these studies. Author also address how other factors influence the interpretation of the studies on DDT, DDE, and breast cancer risk. These include the effect of analytic methods, dietary factors, menopausal status, use of different types of control populations, lactation history, estrogen receptor status, ethnic/racial subgroups, breast tumor characteristics, and polymorphisms
  [Snedeker, S, M. 2001. Environ Health Perspect; 109(Suppl 1): 35–47]
• Maternal body burden of organochlorine pesticides and dioxins
  This study investigated the body burden of organochlorine pesticides and dioxins in Japanese women. 125 milk samples were collected from 41 mothers in 1994, 42 in 1995, and 42 in 1996. Dieldrin, heptachor epoxide, oxychlordane, trans-chlordane, and cis-chlordane were detected at lower average levels. Dioxins were detected in all samples. Levels of the analytes also significantly increased depending on mother's age.
  [Nakagawa R, Hirakawa H, Iida T, Matsueda T, Nagayama J. 1999. J AOAC Int.;82(3):716-24]
• Human milk as a bioindicator for body burden of PCDDs, PCDFs, organochlorine pesticides, and PCBs.
  Researchers collected samples on a voluntary basis from nursing mothers and analyzed them for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). More than 1400 individual milk samples have been analyzed for organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The 2 yr investigations revealed somewhat lower levels compared to former years. This might be an indication that the efforts undertaken to minimize dioxin emissions and to shut down known sources have already had an effect on the body burden of humans. Although mostly banned for a considerable period of time now, some lipophilic persistent pesticides such as DDT, dieldrin, hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCH) can still be found in human milk.
  [Fürst P, Fürst C, Wilmers K. 1994. Environ Health Perspect.;102 Suppl 1:187-93]

Urine and other compartments

• Estrogenic and androgenic activities in total plasma measured with reporter-gene bioassays: Relevant exposure measures for endocrine disruptors in epidemiologic studies?
  The objective of this study was to explore the effects of a variety of sources of potential endocrine disruptors on estrogenic and androgenic activities in total plasma measured by Chemically Activated LUciferase gene eXpression (CALUX®). Plasma samples and interview data on sources of potential endocrine disruptors were collected from 108 men with different exposures profiles. Mean differences (beta) in 17ß-estradiol equivalents (EEQs) and dihydrotestosterone equivalents (AEQs) between exposure groups were estimated using general linear models. Mean plasma AEQs and EEQs were 9.1×10(-1)ng/ml and 12.0pg/ml, respectively. Elevated AEQs were found in smokers and heavy drinkers, and in men occupationally exposed to disinfectants or welding/soldering fumes. Occupational exposure to pesticides, disinfectants, and exhaust fumes seemed to be associated with increased plasma EEQs: 1.5 (-0.2-3.2)pg/ml, 2.1 (0.2-3.9)pg/ml, and 2.9 (0.6-5.2)pg/ml, respectively. Moderate to high plasma dioxin levels, measured in a subgroup by the dioxin-responsive CALUX®, were accompanied by a 20% increase in AEQs. Although the results are not yet readily interpretable, they indicate that these measurements can be valuable for epidemiologic studies on endocrine disruptors and give direction for further research.
  [Brouwers MM et al. 2011. Environ Int.;37(3):557-64]
• Halogenated POPs and PAHs in Blood Plasma of Hong Kong Residents
  The objective of this study was to quantify organic chlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in blood plasma collected from 111 healthy residents in Hong Kong to assess the levels of these pollutants in the general population during the period of March to April, 2008. Naphthalene, phenanthrene, p,p'-DDE, PCB-180, and PBDE-47 were detected in 100% of the participants. Females had significantly greater concentrations of acenaphthylene (female: 93.3 ng/g lipid; male: 39.8, p < 0.05), anthracene (22.3; 15.3, p < 0.05), fluoranthene (138; 125, p < 0.05), p,p'-DDE, p,p'-DDT, PCB-183, BDE-99 than males. Blood of smokers contained significantly greater (p < 0.05) concentrations of acenaphthene, benzo(a)pyrene, p,p'-DDE, p,p'-DDT, PCB-138, BDE-47, and BDE-99 than did blood of nonsmokers. Positive correlations were found between concentrations of each class of pollutant, with respect to seafood diet habit, Body Mass Index (BMI), and age. Concentrations of HCHs and DDTs in blood plasma of healthy Hong Kong residents were greater than those of other countries, and it was found that smoking, consumption of a seafood diet, BMI, and age could influence concentrations in human blood.
  [Qin YY, et al. 2011. Environ Sci Technol. [Epub ahead of print]
• Pesticide exposure among pregnant women in Jerusalem, Israel: results of a pilot study
  Authors measured urinary concentrations of organophosphorus (OP) insecticide metabolites and plasma concentrations of OP and other pesticides in 20 pregnant women, recruited in Jerusalem, Israel in 2006, and collected questionnaire data on demographic factors and consumer habits from these women. Study compared creatinine-adjusted OP pesticide metabolite concentrations, as well as plasma pesticide concentrations, with other populations of pregnant women. Creatinine-adjusted total dimethyl (DM) metabolite concentrations were between 4 and 6 times higher in this population compared to other populations of pregnant women in the United States while total diethyl (DE) metabolite concentrations were lower. Dimethylphosphate (DMP) was detected in 74% of the urine samples whereas dimethylthiophosphate (DMTP) was detected in 90% of the urine samples. The carbamate bendiocarb was detected in 89% of the plasma samples, while the OP insecticide chlorpyrifos was detected in 42% of the samples. Mean plasma concentrations of bendiocarb and chlorpyrifos in our sample were 4.4 and 3.9 times higher, respectively, than that of an urban minority cohort from New York City. Twelve women (63%) reported using some form of household pest control during their pregnancy and five (26%) reported using household pest control during the past month. Women with a graduate degree had significantly higher geometric mean concentrations of total urinary DM metabolite concentrations compared to other women. It is unclear why total DM metabolites concentrations were much higher in this population compared to other populations of pregnant women in the United States and Netherlands.
  [Berman T et al. 2011. Environ Int.;37(1):198-203]
• Peripheral precocious puberty in a 4-month-old girl: role of pesticides?
  A 4-month-old girl presented with sexual development, including breast enlargement, menstruation, uterine length of 69mm at ultrasonography, and dramatically high estrogen bioactivity, but no growth acceleration, pubic hair, pelvis masses or adrenal tumors. Gas chromatography with an electron capture detector and mass spectrometry detected pesticides (p,p-DDD, p,p-DDT, lindane and endosulfan sulpfate) in plasma from the infant, the mother, and the 38-year-old father, who reported a dramatic decrease in libido, and in soil samples from their farm. The precocious sexual development was probably caused by the estrogen activity of the environmental contamination by tons of pesticides stored in the family farm.
  [Gaspari L, Paris FO, Jeandel C, Sultan C. 2011. Gynecol Endocrinol. doi:10.3109/09513590.2010.526666]
• Lower birth weight and increased body fat at school age in children prenatally exposed to modern pesticides: a prospective study
  In this prospective study of 247 children born by women working in greenhouses in early pregnancy, 168 were categorized as prenatally exposed to pesticides. At three months and at 6 to 11 years of age the children underwent a clinical examination and blood sampling for analysis. Body fat percentage was also calculated. Compared to unexposed children birth weight and weight for gestational age were lower in the highly exposed children and medium exposed children. Exposed children had significantly larger increase in BMI Z-score from birth to school age and highly exposed children had 15.8% larger skin folds and higher body fat percentage. If prenatally exposed to both pesticides and maternal smoking, the sum of four skin folds was 46.9% and body fat percentage 29.1% higher.
  [Wohlfahrt-Veje, C., K. Main, I. Schmidt, M. Boas, T. Jensen, P. Grandjean, et al. 2011. Environ Health.10:79.]
  
• Environmental Chemicals in Pregnant Women in the US: NHANES 2003-2004.
  Study analyzed biomonitoring data from the National Health and Nutritional Examination Survey (NHANES) to characterize both individual and multiple chemical exposures in U.S. pregnant women. Data for 163 chemical analytes in 12 chemical classes for subsamples of 268 pregnant women from NHANES 2003-2004, a nationally representative sample of the U.S. population, were analyzed. The percent of pregnant women with detectable levels of an individual chemical ranged from 0 to 100 percent. Certain PCBs, organochlorine pesticides, PFCs, phenols, PBDEs, phthalates, polycyclic aromatic hydrocarbons (PAHs) and perchlorate were detected in 99 to 100% of pregnant women. The median number of detected chemicals by chemical class ranged from 4 (out of 12 PFCs) to 9 (out of 13 phthalates). Across chemical classes, median number ranged from 8 (out of 17 chemical analytes) to 50 (out of 71 chemical analytes). Generally, levels in pregnant women were similar or lower than levels in non-pregnant women, adjustment for covariates tended to increase levels in pregnant women compared to non-pregnant women. Authors conlude, pregnant women in the U.S. are exposed to multiple chemicals. Further efforts are warranted to understand sources of exposure and implications for policy-making.
  [Woodruff TJ, Zota AR, Schwartz JM. 2011. Environ Health Perspect. doi: 10.1289/ehp.1002727 ]
• Biomonitoring data for 2,4-dichlorophenoxyacetic acid in the United States and Canada: interpretation in a public health risk assessment context using Biomonitoring Equivalents
  Authors reviewed the available biomonitoring data for 2,4-D from the United States and Canada and compared them with Biomonitoring Equivalents (Bes) values to draw conclusions regarding the margin of safety for 2,4-D exposures within each population group. Biomonitoring data from these studies indicate that current exposures to 2,4-D are below applicable exposure guidance values. This review demonstrates the value of biomonitoring data in assessing population exposures in the context of existing risk assessments using the BE approach. Risk managers can use this approach to integrate the available biomonitoring data into an overall assessment of current risk management practices for 2,4-D.
  [Aylward LL et al. 2010. Environ Health Perspect. 118(2):177-81]
• Pesticide concentrations in maternal and umbilical cord sera and their relation to birth outcomes in a population of pregnant women and newborns in New Jersey
  Study evaluated in utero exposures to pesticides by measuring maternal and cord serum biomarkers in a New Jersey cohort of pregnant women and the birth outcomes of their neonates. Authors evaluated the following pesticide compounds in both maternal and umbilical cord sera: chlorpyrifos, diazinon, carbofuran, chlorothalonil, dacthal, metolachlor, trifluralin and diethyl-m-toluamide (DEET). Of these compounds, chlorpyrifos, carbofuran, chlorothalonil, trifluralin, metolachlor and DEET were the pesticides most frequently detected in the serum samples. High (≥75th percentile) metolachlor concentrations in cord blood were related to birth weight. An increase in abdominal circumference with increasing cord dichloran concentrations was also observed. These observations suggest that in utero exposures to certain pesticides may alter birth outcomes.
  [Barr, D. et al. 2010. Sci Total Environ. 408(4):790-5]
  
• Urinary concentrations of metabolites of pyrethroid insecticides in the general U.S. population: National Health and Nutrition Examination Survey 1999-2002
  The objective was to assess human exposure via biomonitoring to pyrethroid insecticides in a representative sample of the general U.S. population >or= 6 years of age. Researchers measured five urinary metabolites of pyrethroid insecticides in 5,046 samples collected as a part of the 1999-2002 National Health and Nutrition Examination Survey (NHANES). Results detected 3-phenoxybenzoic acid (3PBA), a metabolite common to many pyrethroid insecticides, in more than 70% of the samples. Non-Hispanic blacks had significantly higher 3PBA concentrations than did non-Hispanic whites and Mexican Americans in the 2001-2002 survey period and in the combined 4-year survey periods but not in the 1999-2000 survey period. Children had significantly higher concentrations of 3PBA than did adolescents in both NHANES periods and than adults in NHANES 1999-2000. Cis- and trans-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid were highly correlated with each other and with 3PBA, suggesting that urinary 3PBA was derived primarily from exposure to permethrin, cypermethrin, or their degradates. Study concludes pyrethroid insecticide exposure in the U.S. population is widespread, and the presence of its metabolites in the urine of U.S. residents indicates that children may have higher exposures than adolescents and adults.
  [Barr DB, et al. 2010. Environ Health Perspect.;118(6):742-8]
• Assessing Children’s Dietary Pesticide Exposure: Direct Measurement of Pesticide Residues in 24-hr Duplicate Food Samples
  Researchers measured pesticide residues in 24-hr duplicate food samples collected from a group of 46 young children participating in the Children's Pesticide Exposure Study (CPES). Samples of all conventional fruits, vegetables, and fruit juices equal to the quantity consumed by their children, similarly prewashed/ prepared, and from the same source or batch. Individual or composite food items were analyzed for organophosphate (OP) and pyrethroid insecticide residues. Auhors found 14% or 5% of those food samples contained at least one OP or pyrethroid insecticide, respectively. We measured a total of 11 OP insecticides, at levels ranging from 1 to 387 ng/g, and three pyrethroid insecticides, at levels ranging from 2 to 1,133 ng/g, in children's food samples. The frequent consumption of food commodities with episodic presence of pesticide residues that are suspected to cause developmental and neurological effects in young children supports the need for further mitigation.
  [ Lu C, Schenck FJ, Pearson MA, Wong JW.2010. Environ Health Perspect.118(11):1625-30.]
  Plasma organochlorine levels and risk of non-Hodgkin lymphoma in the Nurses' Health Study
  Numerous studies have reported positive associations of environmental exposure to polychlorinated biphenyls (PCB) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) with the risk of non-Hodgkin lymphoma (NHL). In a case-control study nested within the Nurses' Health Study, a prospective cohort of U.S. women, we measured concentrations of PCBs and p,p'-DDE in blood samples from 145 women diagnosed with NHL at least 6 months after blood draw and 290 age- and race-matched controls. We used conditional logistic regression to estimate the odds ratios and 95% confidence intervals for each quartile of exposure relative to the lowest quartile. We also evaluated these associations for major histologic subtypes of NHL. There was no consistent evidence of an association of p,p'-DDE, total PCBs, immunotoxic, or individual PCB congeners with risk of NHL. These results do not support the hypothesis of a positive association between PCB exposure and development of NHL.
  [Laden F et al. 2010. Cancer Epidemiol Biomarkers Prev.19(5):1381-4]
• Evaluating cumulative organophosphorus pesticide body burden of children: a national case study
  Biomonitoring is a valuable tool for identifying exposures to chemicals that pose potential harm to human health. However, to date there has been little published on ways to evaluate the relative public health significance of biomonitoring data for different chemicals and even less on cumulative assessment of multiple chemicals. The objectives of this study were to develop a methodology for a health risk interpretation of biomonitoring data and to apply it using NHANES 1999-2002 body burden data fororganophosphorus (OP) pesticides. OP pesticides present a particularly challenging case given the nonspecificity of manymetabolites monitored through NHANES. Study back-calculates OP pesticide exposures from urinary metabolite data and compares cumulative dose estimates with available toxicity information for a common mechanism of action (brain cholinesterase inhibition) using data from U.S. EPA. Results suggest that approximately 40% of children in the United States may have had insufficient margins of exposure (MOEs) for neurological impacts from cumulative exposures to OP pesticides (MOE less than 1000). Limitations include uncertainty related to assumptions about likely precursor pesticide compounds of the urinary metabolites, sources of exposure, and intraindividual and temporal variability.
  [Payne-Sturges D, Cohen J, Castorina R, Axelrad DA, Woodruff TJ. 2009. Environ Sci Technol. 15;43(20):7924-30]
• Genotoxic biomonitoring of agricultural workers exposed to pesticides in the north of Sinaloa State, Mexico
  Genotoxic damage was evaluated in 70 agricultural workers, 25 women and 45 men, exposed to pesticides in Las Grullas, Ahome, Sinaloa, Mexico, with an average of 7 years of exposure. The effect was detected through the sister chromatid exchanges (SCE) in lymphocytes of peripheral blood and micronuclei (MN) and other nuclear anomalies (NA) in buccal exfoliated cells. Also, the influence on cellular proliferation kinetics (CPK) was studied by means of the replication index (RI) and the cytotoxic effect was examined with the mitotic index (MI). The non-exposed group consisted of 70 other persons, 21 women and 47 men from the city of Los Mochis, Sinaloa, Mexico. Significant differences between the exposed and the non-exposed groups were observed in SCE, CPK, MI, MN and NA. Analysis of variance revealed that age, gender, smoking and alcohol consumption did not have a significant effect on genetic damage. However, there was a correlation between exposure time to pesticides and SCE frequency. These results could have been due to the exposure of workers to pesticides containing different chemical compounds. This study afforded valuable data to estimate the possible risk to health associated with pesticide exposure.
  [Martínez-Valenzuela C. et al. 2009. Environ Int;35(8):1155-9]
• Organochlorine and heavy metals in newborns: results from the Flemish Environment and Health Survey (FLEHS 2002-2006)
  To collect regional information on internal levels of pollutants in humans in Flanders, 1196 mother-child pairs were systematically recruited in 2002-2003 via 25 maternities across Flanders. Cd, Pb, PCB congeners, p,p'-DDE - a key metabolite of DDT- and hexachlorobenzene (HCB) were measured in cord blood or plasma. Cd was detected in 64% of the samples. p,p'-DDE and Pb were measurable in nearly all samples. The individual PCB congeners could be detected in 40 to 81% of the newborns. HCB and dioxin-like compounds were above detection limit in more than 75% of the samples. Age and smoking habits of the mothers, did not influence the cord blood Pb and Cd levels. The organochlorines increased 4 to 9% per year of the mother's age. Mothers had 2.6% less PCBs in cord blood for each unit increase in pre-pregnancy BMI. Season of delivery, breastfeeding previous children or consumption of local dairy products, were minor determinants. Up to 20% of the variability in organochlorine concentrations was explained by residence area. It was concluded that the place of birth in Flanders is an important determinant of the load of pollutants measured at the start of life. This underlines the validity of human biomonitoring on (relatively) small geographical scale.
  [Koppen G et al. 2009. Environ Int.;35(7):1015-22]
• Biomonitoring of exposure to pesticides
  Many biomonitoring methods have employed analytical techniques such as chromatography and mass spectrometry to accurately measure urinary metabolites or blood body burdens of several classes of pesticides. The pesticides assessed include the banned organochlorine pesticides, the more modern organophosphorus, carbamate, and pyrethroid insecticides along with a variety of herbicides including phenoxyacetic acids and triazines. These methods are capable of detecting concentrations in biological samples resulting from occupational exposures to pesticides, and in some instances, general background exposures from residential or dietary exposures. These data have been used for a variety of applications. They have documented the pervasiveness of pesticide exposures, have allowed us to determine the primary predictors of exposure in certain populations, have helped us to identify the most important pathways of exposure, and have helped us to better understand any potential risks associated with exposures. In addition, these methods have helped us to document poisoning cases and identify etiologic agents in crisis situations. This review discusses the methods that have been employed over the last 40 years and how these methods have addressed critical public health questions.
  [Barr, D. 2008. Journal of Chemical Health and Safety 15(6):20-29]
• The influence of age and gender on triclosan concentrations in Australian human blood serum.
  Recent in vitro and in vivo studies indicate that triclosan might exert adverse effects in humans. triclosan has previously been shown to be present in human plasma and milk at concentrations that are well correlated to the use of personal care products containing triclosan. In this study authors investigated the influence of age, gender, and the region of residence on triclosan concentrations in pooled samples of Australian human blood serum. The results showed no influence of region of residence on the concentrations of triclosan. There was a small but significant influence of age and gender on the serum triclosan concentrations, which were higher in males than in females, and highest in the group of 31-45 year old males and females. However, overall there was a lack of pronounced differences in the triclosan concentrations within the dataset, which suggests that the exposure to triclosan among different groups of the Australian population is relatively homogenous. A selection of the dataset was compared with previous measurements of triclosan concentrations in human plasma from Sweden, where the use of triclosan is expected to be low due to consumer advisories. The triclosan concentrations were a factor of 2 higher in Australian serum than in Swedish plasma.
  [Allmyr M, et al. 2008. Sci Total Environ. ;393(1):162-7]
• Urinary concentrations of triclosan in the U.S. population: 2003-2004.
  This study was designed to assess exposure to triclosan in a representative sample > or = 6 years of age of the U.S. general population from the 2003-2004 National Health and Nutrition Examination Survey (NHANES). Study analyzed 2,517 urine samples and detected concentrations of total (free plus conjugated) triclosan in 74.6% of samples at concentrations of 2.4-3,790 microg/L. Concentrations of triclosan were higher in people in the high household income than in people in low and medium income categories. In about three-quarters of urine samples analyzed as part of NHANES 2003-2004, we detected concentrations of triclosan. Concentrations differed by age and socioeconomic status but not by race/ethnicity and sex. Specifically, the concentrations of triclosan appeared to be highest during the third decade of life and among people with the highest household incomes.
  [Calafat AM, Ye X, Wong LY, Reidy JA, Needham LL. 2008. Environ Health Perspect ;116(3):303-7]
• Environmental chemicals in people: challenges in interpreting biomonitoring information.
  Biomonitoring, the measurement of chemicals in blood, urine, and other tissues or fluids, is becoming an increasingly common tool in the study of human exposure to environmental chemicals and the potential health effects of those chemicals. The National Health and Nutrition Examination Survey (NHANES) now includes biomonitoring data for hundreds of chemicals as well as information on other health and demographic endpoints for thousands of individuals in the United States. The NHANES databases provide valuable information for deriving reference ranges and trend information and can be used for hypothesis-generating analyses, but they cannot be used to establish causal relationships between environmental chemicals and health effects. This commentary examines issues unique to the use of such databases and the interpretation of biomonitoring-based epidemiological studies.
  [LaKind JS, Barraj L, Tran N, Aylward LL. 2008. J Environ Health ;70(9):61-4]
• Dietary Intake and Its Contribution to Longitudinal Organophosphorus Pesticide Exposure in Urban/suburban Children.
  Study assessed young urban/suburban children's longitudinal exposure to OP pesticides in the Children's Pesticide Exposure Study (CPES).Twenty-three children 3-11 years of age who consumed only conventional diets were recruited for this 1-year study conducted in 2003-2004. Children switched to organic diets for 5 consecutive days in the summer and fall sampling seasons. Study measured specific urinary metabolites for malathion, chlorpyrifos, and other OP pesticides in urine samples collected twice daily for a period of 7, 12, or 15 consecutive days during each of the four seasons. By substituting organic fresh fruits and vegetables for corresponding conventional food items, the median urinary metabolite concentrations were reduced to nondetected or close to non-detected levels for malathion and chlorpyrifos at the end of the 5-day organic diet intervention period in both summer and fall seasons. Study also observed a seasonal effect on the OP urinary metabolite concentrations, and this seasonality corresponds to the consumption of fresh produce throughout the year. The findings from this study demonstrate that dietary intake of OP pesticides represents the major source of exposure in young children.
  [Lu C, Barr DB, Pearson MA, Waller LA. 2008. Environ Health Perspect. 216(4):537-42.]
• Merging Models and Biomonitoring Data to Characterize Sources and Pathways of Human Exposure to Organophosphorus Pesticides in the Salinas Valley of California
  The study population is the CHAMACOS cohort of almost 600 pregnant Latina women in the Salinas Valley region. Study uses model estimates of organophosphate (OP) intake and urinary dialkylphosphate (DAP) metabolite excretion to develop premises about relative contributions from different exposure sources and pathways. Researchers evaluated these premises by comparing the magnitude and variation of DAPs in the CHAMACOS cohort with those of the whole U.S. population using data from the National Health and Nutrition Examination Survey (NHANES). This comparison supports the premise that diet is the common and dominant exposure pathway in both populations. Biomarker comparisons and model results support the observation that, relative to NHANES, the CHAMACOS population has a statistically significant added intake of OP pesticides with low inter-individual variability. Authors attribute the magnitude and small variance of this intake to residential nondietary exposures from local agricultural OP uses. These results show that mass-balance models can estimate exposures for OP pesticides within the range measured by biological monitoring.
  [McKone, T. et al. 2007. Environ. Sci. Technol. 41 (9): 3233–3240]
• Agreement of pesticide biomarkers between morning void and 24-h urine samples from farmers and their children
  In pesticide biomonitoring studies, researchers typically collect either single voids or daily (24-h) urine samples. Collection of 24-h urine samples is considered the "gold-standard", but this method places a high burden on study volunteers, requires greater resources, and may result in misclassification of exposure or underestimation of dose due to noncompliance with urine collection protocols. To evaluate the potential measurement error introduced by single void samples, we present an analysis of exposure and dose for two commonly used pesticides based on single morning void (MV) and 24-h urine collections in farmers and farm children. The agreement between the MV concentration and its corresponding 24-h concentration was analyzed using simple graphical and statistical techniques and risk assessment methodology. A consistent bias towards overprediction of pesticide concentration was found among the MVs, likely in large part due to the pharmacokinetic time course of the analytes in urine. These results suggest that the use of single voids can either over- or under-estimate daily exposure if recent pesticide applications have occurred. This held true for both farmers as well as farm children, who were not directly exposed to the applications. As a result, single void samples influenced the number of children exposed to chlorpyrifos whose daily dose estimates were above levels of toxicologic significance. In populations where fluctuations in pesticide exposure are expected (e.g., farm families), the pharmacokinetics of the pesticide and the timing of exposure events and urine collection must be understood when relying on single voids as a surrogate for longer time-frames of exposure.
  [Scher, D. et al. 2007, J. Exposure Science and Environmental Epidemiology; 17, 350–357]
• Pesticides and Childhood Cancer: An Update of Zahm and Ward’s 1998 Review
  Children are exposed to pesticides through a number of sources, including residential and agricultural applications. Parental occupational exposure to pesticides is also a concern because exposures occurring during pregnancy and carry-home residues also contribute to children's cumulative burden. A number of epidemiological studies consistently reported increased risks between pesticide exposures and childhood leukemia, brain cancer, neuroblastoma, non-Hodgkin's lymphoma, Wilms' tumor, and Ewing's sarcoma. An extensive review of these studies was published in 1998 (Zahm & Ward, 1998). Fifteen case-control studies, 4 cohort studies, and 2 ecological studies have been published since this review, and 15 of these 21 studies reported statistically significant increased risks between either childhood pesticide exposure or parental occupational exposure and childhood cancer. Therefore, one can confidently state that there is at least some association between pesticide exposure and childhood cancer. However, an unambiguous mechanistic cause-and-effect relationship between pesticide exposure and childhood cancer was not demonstrated in these studies, and modifying factors such as genetic predisposition, rarely considered in the reviewed studies, likely play an important role.
  [Infante-Rivard C, Weichenthal S. 2007. J Toxicol Environ Health B Crit Rev. 10(1-2):81-99.]
• Reference values for metabolites of pyrethroid and organophosphorous insecticides in urine for human biomonitoring in environmental medicine
  With reliable and sensitive analytical methods for detecting metabolites of organophosphorous and pyrethroid insecticides in urinary specimens of the general population several studies have been published on internal exposure to these insecticides of the population in Germany. In Germany, reference values for environmental pollutants related to the population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency, preferably based on data gained by representative studies. Since there is a need for reference values to characterise the population's exposure to organophosphates and pyrethroids, and since there are different studies available from Germany that agree quite well with data from other industrialised countries, the Commission has derived reference values from the available data, though none of the studies had fulfilled criteria on representativity. Reference values for metabolites of organophosphorous acids are as follows: DMP 135 µg/l, DMTP 160 µg/l and DEP 16 µg/l and for metabolites of pyrethroids: cis-Cl2CA 1 µg/l, trans-Cl2CA 2 µg/l and 3-PBA 2 µg/l. As the volume-related concentrations of organophosphate and pyrethroid metabolites show no significant age-dependence, the reference values derived are not age-stratified. Though based merely on statistical and not on toxicological data, levels analysed above the reference levels, when reliably measured (verified several times), should prompt environmental health practitioners to search for sources, within the bounds of proportionality. In addition to accidental poisoning, possible sources include indoor contamination following improper pest control operations in homes as well as in pets and food products contaminated by these pesticides.
  [Heudorf, U., Butte, W., Schulz, C., and Angerer. J. 2006. International Journal of Hygiene and Environmental Health, 209(3):293-299]
• Effects of processing on pesticide residues in peaches intended for baby food.
  Peaches containing added residues of chlorpyrifos-methyl, fenitrothion, procymidone and vinclozolin were used for simulated industrial processing in the manufacture of baby food puree. Residues were determined in raw material, in intermediate products at crucial steps of the processing procedure and in final products. The results of the study were interpreted with respect to enforcement of the stringent Maximum Residue Limit (MRL) of 0.01 mg kg-1 established by the European Commission (EC) for any pesticide in baby food. Peeling was identified as the most effective procedure in reducing residues. Thermal treatment (concentration and sterilisation) substantially reduced organophosphate (chlorpyrifos-methyl, fenitrothion) residues, whereas procymidone and vinclozolin residue levels were increased in peach puree.
  [Balinova AM, Mladenova RI, Shtereva DD. 2006. Food Addit Contam.23(9):895-901]
• A Longitudinal Approach to Assessing Urban and Suburban Children’s Exposure to Pyrethroid Pesticides
  Researchers conducted a longitudinal study to assess the exposure of 23 elementary school-age children to pyrethroid pesticides, using urinary pyrethroid metabolites as exposure biomarkers. Most of the children's conventional diets were substituted with organic food items for 5 consecutive days and two daily spot urine samples wrer collected, throughout the 15-day study period. Yrine samples for five common pyrethroid metabolites were analyzed. Authors found an association between the parents' self-reported pyrethroid use in the residential environment and elevated pyrethroid metabolite levels found in their children's urine. Children were also exposed to pyrethroids through their conventional diets, although the magnitude was smaller than for the residential exposure. Children's ages appear to be significantly associated with pyrethroids exposure, which is likely attributed to the use of pyrethroids around the premises or in the facilities where older children engaged in the outdoor activities. Study concludes that residential pesticide use represents the most important risk factor for children's exposure to pyrethroid insecticides. Because of the wide use of pyrethroids in the United States, the findings of this study are important for both children's pesticide exposure assessment and environmental public health.
  [ Lu C, Barr DB, Pearson M, Bartell S, Bravo R.. 2006. Environ Health Perspect. 114(9):1419-23.]
  Triclosan in plasma and milk from Swedish nursing mothers and their exposure via personal care products
  In this study, plasma and milk were sampled from 36 mothers and analyzed for triclosan. Scrutinization of the women's personal care products revealed that nine of the mothers used toothpaste, deodorant or soap containing triclosan. Triclosan and/or its metabolites were omnipresent in the analyzed plasma and milk. The concentrations were higher in both plasma and milk from the mothers who used personal care products containing triclosan than in the mothers who did not. This demonstrated that personal care products containing triclosan were the dominant, but not the only, source of systemic exposure to triclosan. The concentrations were significantly higher in plasma than in milk, indicating that infant exposure to triclosan via breast milk is much less than the dose in the mother.
  [Allmyr M, Adolfsson-Erici M, McLachlan MS, Sandborgh-Englund G. 2006. Sci Total Environ.;372(1):87-93]
  
• Potential Uses of Biomonitoring Data: A Case Study Using the Organophosphorus Pesticides Chlorpyrifos and Malathion
  Biologic monitoring has been widely used to assess exposures, susceptibility, and effects of chlorpyrifos and malathion. For biomonitoring of exposure, chlorpyrifos and malathion have been measured in blood, but most typically their urinary metabolites have been measured. Although many biologic monitoring data have been generated and published on these chemicals, their interpretation is not straightforward. For example, exposure to environmental degradates of chlorpyrifos and malathion may potentially increase f urinary metabolite levels, thus leading to overestimation of exposure. Also, the temporal nature of the exposures makes the evaluation of both exposure and effects difficult. Authors present an overview of the current biomonitoring and other relevant data available on exposure to chlorpyrifos and malathion and the use of these data in various environmental public health applications.
  [Barr, D, B. and Angerer, J. 2006. Environ Health Perspect; 114(11): 1763–1769]
• Biomonitoring: is body burden relevant to public health?
  Biomonitoring is the study of the presence and concentration of chemicals in humans usually by the measurement of blood, urine or breath (exhaled air). Properly conducted, these data provide a picture of the amount of a chemical or agent actually absorbed into the body for a specific period of time. This review provides a history of biomonitoring, as well as the limitations and potential benefits of these studies. Examples of the proper and possibly improper use of biomonitoring and the impact made on our society are provided. Reasons for having comprehensive national biomonitoring programs are summarized, along with the societal benefits and risks. A brief discussion of the history of the NHANES program and select results from the 2005 Report are presented. By 2010, it has been predicted that the Centers for Disease Control (CDC) will be monitoring nearly 1000 chemicals in persons from all regions of the nation. The measurement of chemicals and biomarkers has revolutionized the field of exposure assessment. Overall, we recommend an approach of careful interpretation, understanding that the data obtained are useful for establishing baseline information about exposure, rather than equating detection with risk. We present suggestions for contextualizing biomonitoring results in order to provide the public with the tools to distinguish genuine health risks from trivial ones.
  [Paustenbach D and Galbraith D. 2005. Regul Toxicol Pharmacol. 44(3):249-6]
• Glyphosate biomonitoring for farmers and their families: results from the Farm Family Exposure Study.
  Glyphosate is the active ingredient in Roundup agricultural herbicides and other herbicide formulations that are widely used for agricultural, forestry, and residential weed control. As part of the Farm Family Exposure Study, we evaluated urinary glyphosate concentrations for 48 farmers, their spouses, and their 79 children (4-18 years of age). We evaluated 24-hr composite urine samples for each family member the day before, the day of, and for 3 days after a glyphosate application. Sixty percent of farmers had detectable levels of glyphosate in their urine on the day of application. The geometric mean (GM) concentration was 3 ppb, the maximum value was 233 ppb, and the highest estimated systemic dose was 0.004 mg/kg. Farmers who did not use rubber gloves had higher GM urinary concentrations than did other farmers (10 ppb vs. 2.0 ppb). For spouses, 4% had detectable levels in their urine on the day of application. Their maximum value was 3 ppb. For children, 12% had detectable glyphosate in their urine on the day of application, with a maximum concentration of 29 ppb. All but one of the children with detectable concentrations had helped with the application or were present during herbicide mixing, loading, or application. None of the systemic doses estimated in this study approached the U.S. Environmental Protection Agency reference dose for glyphosate of 2 mg/kg/day. Nonetheless, it is advisable to minimize exposure to pesticides, and this study did identify specific practices that could be modified to reduce the potential for exposure.
  [Acquavella, J, F. et al. 2004. Environ Health Perspect; 112(3): 321–326]
• The importance of diet on exposure to and effects of persistent organic pollutants on human health in the Arctic
  Authors describe the importance of diet on exposure to and possible health effects of persistent organic pollutants (POPs) in the Arctic. Minor decreases in POPs and minor increases in Hg levels in Arctic populations in Greenland, Eastern Russia, Western Alaska and Eastern Canada are likely to occur by the year 2010 and major decreases in both POPs and Hg levels in these same populations by 2030. Levels of POPs and metals in populations in the Faeroe Islands and the Scandinavian countries are already reasonably low and are only likely to decline marginally by 2030. To improve understanding of the health effects associated with exposure to contaminants in the Arctic, authors recommend that circumpolar epidemiological studies should be implemented on a larger scale. MeHg- and POPs-related effects are still the key issues. However, the role of newly discovered contaminants, such as PBDEs (polybrominated diphenyl ethers) and PCNs (polychlorinated naphthalenes), should be investigated, as well as a more nuanced view on human dietary exposure to xenobiotics.
  [Odland JO, Deutch B, Hansen JC, Burkow IC. 2003. Acta Paediatr ;92(11):1255-66]
• Genotoxicity of pesticides: a review of human biomonitoring studies
  Pesticides have been considered potential chemical mutagens: experimental data revealed that various agrochemical ingredients possess mutagenic properties inducing mutations, chromosomal alterations or DNA damage. Biological monitoring provides a useful tool to estimate the genetic risk deriving from an integrated exposure to a complex mixture of chemicals. Studies available in scientific literature have essentially focused on cytogenetic end-points to evaluate the potential genotoxicity of pesticides in occupationally exposed populations, including pesticide manufacturing workers, pesticide applicators, floriculturists and farm workers. A positive association between occupational exposure to complex pesticide mixtures and the presence of chromosomal aberrations (CA), sister-chromatid exchanges (SCE) and micronuclei (MN) has been detected in the majority of the studies, although a number of these failed to detect cytogenetic damage. Conflicting results from cytogenetic studies reflect the heterogeneity of the groups studied with regard to chemicals used and exposure conditions. Genetic damage associated with pesticides occurs in human populations subject to high exposure levels due to intensive use, misuse or failure of control measures. The majority of studies on cytogenetic biomarkers in pesticide-exposed workers have indicated some dose-dependent effects, with increasing duration or intensity of exposure. Chromosomal damage induced by pesticides appears to have been transient in acute or discontinuous exposure, but cumulative in continuous exposure to complex agrochemical mixtures.
  [Bolognesi, C. 2003. Mutation Research/Reviews in Mutation Research, 543(3): 251-272]
• Organophosphorus Pesticide Exposure of Urban and Suburban Preschool Children with Organic and Conventional Diets.
  Study assessed organophosphorus (OP) pesticide exposure from diet by biological monitoring among Seattle, Washington, preschool children. Parents kept food diaries for 3 days before urine collection, and they distinguished organic and conventional foods based on label information. Children were then classified as having consumed either organic or conventional diets based on analysis of the diary data. Residential pesticide use was also recorded for each home. 24-hr urine samples were collected from 18 children with organic diets and 21 children with conventional diets and analyzed for five OP pesticide metabolites. Results found significantly higher median concentrations of total dimethyl alkylphosphate metabolites than total diethyl alkylphosphate metabolites. The median total dimethyl metabolite concentration was approximately six times higher for children with conventional diets than for children with organic diets. The dose estimates suggest that consumption of organic fruits, vegetables, and juice can reduce children's exposure levels from above to below the U.S. Environmental Protection Agency's current guidelines, thereby shifting exposures from a range of uncertain risk to a range of negligible risk. Consumption of organic produce appears to provide a relatively simple way for parents to reduce their children's exposure to OP pesticides.
  [Curl, C, Fenske, R, and Elgethun, K. 2003. Environ Health Perspect. 111(3): 377–382.]
• Measurement of pesticides and other toxicants in amniotic fluid as a potential biomarker of prenatal exposure: a validation study.
  Authors collected 100 amniotic fluid samples slated for disposal and evaluated analytical methods to measure organophosphate and carbamate pesticides and metabolites, synthetic pyrethroid metabolites, herbicides, and chlorinated phenolic compounds. The following six phenols were detected (detection frequency): 1- and 2-naphthol (70%), 2,5-dichlorophenol (55%), carbofuranphenol (5%), ortho-phenylphenol (30%), and pentachlorophenol (15%). The organophosphate metabolites diethylphosphate and dimethylphosphate were detected in two (10%) samples, and dimethylthiophosphate was detected in one (5%) sample. These levels are low compared with levels reported in urine, blood, and meconium in other studies, but indicate direct exposures to the young fetus, possibly during critical periods of development. Results of this pilot study suggest that amniotic fluid offers a unique opportunity to investigate fetal exposures and health risks.
  [Bradman,A., Barr, D, Claus Henn, B, Drumheller, T, Curry, C. and Eskenazi, B. 2003. Environ Health Perspect. 111(14): 1779–1782.]
• Analytical methods for biological monitoring of exposure to pesticides: a review
  Synthetic pesticides have been used since in the early to mid twentieth century. In the US alone, over 800 pesticide active ingredients are formulated in about 21 000 different commercial products. Although many public health benefits have been realized by the use of pesticides, their potential impact on the environment and public health is substantial. For risk assessment studies, exposure assessment is an integral component, which has unfortunately, often been weak or missing. In the past several decades, researchers have proposed to fill these missing data gaps using biological monitoring of specific markers related to exposures. In this paper, authors present a review of existing analytical methodology for the biological monitoring of exposure to pesticides. They also present a critical assessment of the existing methodology and explore areas in which more research is needed.
  [Barr, D and Needham, L. 2002. Journal of Chromatography B 778 (1-2); 5-29]
• Measurement of organophosphate metabolites in postpartum meconium as a potential biomarker of prenatal exposure: a validation study.
  Experimental data have linked exposure to prenatal organophosphates to adverse neurocognitive sequalae. However, epidemiologic research has been hampered by lack of reliable dosimeters. Existing biomarkers reflect short-term exposure only. Measurements of pesticides in postpartum meconium may yield a longer-term dosimeter of prenatal exposure. As the initial step in biomarker validation, this research determined background levels, detection limits, and stabilities of six organophosphate metabolites in meconium: diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), dimethylphosphate (DMP), dimethylthiophosphate (DMTP), and dimethyldithiophosphate (DMDTP). The meconium was collected from 20 newborns at New York Presbyterian Hospital; analyses were undertaken at the Centers for Disease Control and Prevention (CDC). DEP was detected in 19/20 samples and DETP was detected in 20/20. DMP and DEDTP were each detected in 1/20 (at 16 and 1.8 microg/g, respectively). DMTP and DMDTP were not detected. Levels were similar to those seen in adult urine in population-based research. Results indicate that measurements of organophosphate metabolites in meconium have promise as biomarkers of prenatal exposure. Further research is needed to determine the time frame of exposure represented by pesticide levels in meconium and to evaluate the dose-response relationship.
  [Whyatt, RM and Barr, DB. 2001. Environ Health Perspect. 109(4): 417–420]
• Biomonitoring of persons exposed to insecticides used in residences
  Pesticides used indoors inevitably result in some unintentional and unavoidable exposures of residents. Measured dosages of residents are well below toxic levels. Exposures are substantially less and occur over a longer time than suggested by unvalidated estimates derived from previous extreme, conservative default assumptions based solely on environmental residues. Human chlorpyrifos exposures were monitored following three different types of applications: fogger, broadcast, and crack-and-crevice. Persistence of total residue on carpet was substantially greater than the persistence of transferable residue. Low-level exposures of family members persisted for periods of weeks to a month after pesticide use. Although few children who resided with their parents in pest-protected homes have been monitored, they eliminated more biomarker than their parents on a kg body weight-day basis when absorbed dosages were derived from spot urine specimens corrected for volume by an age-specific creatinine correction. Ultimately environmental residues may become useful elements of predictive residential exposure models, but their potential contribution to indirect exposure assessments must include careful determination of residue availability for contact transfer to clothing or skin and biological validation. Experimental and situational monitoring of exposed persons is essential for meaningful and responsible predictive resident exposure model building.
  [Krieger, R.I., Bernard, C.E., Dinoff, T.M., Ross J.H. and Williams R.L. 2001. Ann Occup Hyg, 45 (suppl 1): S143-S153. doi: 10.1093/annhyg/45.suppl_1.S143]
• Potential exposure and health risks of infants following indoor residential pesticide applications.
  The current study was conducted in two apartments and examines the accumulation of the pesticide chlorpyrifos in childrens' toys after the time suggested for reentry after application. It has been established for the first time that a semivolatile pesticide will accumulate on and in toys and other sorbant surfaces in a home via a two-phase physical process that continues for at least 2 weeks postapplication. A summation of the above for a 3-6-year-old child yielded an estimated nondietary total dose of 208 microg/kg/day. Potential exposure from the inhalation pathway was negligible, while dermal and nondietary oral doses from playing with toys contributed to 39 and 61% of the total dose, respectively. If children with high frequency mouthing behavior are considered as candidates for acute exposure to chlorpyrifos residues, the estimated acute dose could be as high as 356 microg/kg/day. The above information should be used to determine if current procedures for postapplication reentry are sufficient and to evaluate the need for procedures to store frequently used household toys, pillows, and other sorbant objects during insecticidal application.
  [Gurunathan, S., M. Robson, N. Freeman, B. Buckley, A. et al.1998. Environ Health Perspec.t. 106(1): 9–16]
• Biomonitoring for Pesticide Exposure
  The biological monitoring of pesticide residues and metabolites is becoming increasingly important in the surveillance of occupationally and environmentally exposed individuals. Detection of these compounds in the body indicates that an exposure has occurred; that the pesticide is bioavailable, having been absorbed; and that a dose to critical tissues may have been incurred. Biomarker methods such as for adducted proteins or nucleic acids are being investigated for some pesticides. However, the chemical analyses of readily sampled matrices, such as urine and blood, for parent compound and/or metabolite(s) remain the standard tools of the trade. Methods are becoming more sensitive as advances are made in analytical instrumentation systems. Immunochemical methods are being developed and emphasized for screening purposes, as well as for an enhanced sensitivity and the potential to detect parent compound and multiple metabolites through selective cross-reactivity. When initiating the biomonitoring component of an exposure assessment for pesticides an array of decisions must be made, primarily based on what is known about the metabolism of the pesticide of interest. Detectability of pesticide exposure depends upon selecting the most appropriate biological matrix, the dominant analyte(s) in that matrix, and the timing of sample collection relative to exposure. Useful analytical results are dependent on proper handling and storage of biological samples, as well as the availability of sensitive analytical methods. These factors, currently known biomonitoring approaches, and the results of selected recent biomonitoring studies are presented.
  [Nauman, C.H. et al. 1993. Biomarkers of Human Exposure to Pesticides Chapter 1, pp 1–19 ACS Symposium Series, Vol. 542]
• Pesticides in the Diets of Infants and Children
  Groundbreaking report presents the findings on a committee charged with responsibility for examining scientific and policy issues faced by government agencies, particularly EPA, in regulating pesticide residues in foods consumed by infants and children. Specifically, the committee was asked to examine the adequacy of current risk assessment policies and methods; to assess information on the dietary intakes of infants and children; to evaluate data on pesticide residues in the food supply; to identify toxicological issues of greatest concern; and to develop relevant research priorities. The committee considered the development of children from the beginning of the last trimester of pregnancy (26 weeks) through 18 years of age, the point when all biological systems have essentially matured.The committee found both quantitative and occasionally qualitative differences in toxicity of pesticides between children and adults; that quantitative differences in toxicity between children and adults are usually less than a factor of approximately 10-fold; and that infants and children differ both qualitatively and quantitatively from adults in their exposure to pesticide residues in foods.
  [National Research Council. 1993. NATIONAL ACADEMY PRESS. Washington, D.C.]
• Potential exposure and health risks of infants following indoor residential pesticide applications.
  Air and surface chlorpyrifos residues were measured for 24 hours following a 0.5 percent Dursban broadcast application for fleas inside a residence. Two of the three treated rooms were ventilated following application. Maximum air concentrations were measured 3-7 hours post-application. Peak concentrations in the infant breathing zone were 94 micrograms/m3 in the nonventilated room and 61 micrograms/m3 in the ventilated room, and were substantially higher than concentrations in the sitting adult breathing zone. Concentrations of approximately 30 micrograms/m3 were detected in the infant breathing zone 24 hours post-application. Surface residues available through wipe sampling were 0.7-1.6 micrograms/cm2 of carpet on the day of application and 0.3-0.5 micrograms/cm2 24 hours post-application. Estimated total absorbed doses for infants were 0.08-0.16 mg/kg on the day of application and 0.04-0.06 mg/kg the day following application, with dermal absorption representing approximately 68 percent of the totals. These doses are 1.2-5.2 times the human No Observable Effect Level (NOEL). Exposures to cholinesterase inhibiting compounds following properly conducted broadcast applications could result in doses at or above the threshold of toxicological response in infants, and should be minimized through appropriate regulatory policy and public education.
  [Fenske R.A., K. Black, K. Elkner, L. Chorng-Li, M.M. Methner and R. Soto. 1990. Am J Pub Health. 80(6): 689-93.]

Farmworkers and Farmworker Children

• Acute Pesticide Illnesses Associated with Off-Target Pesticide Drift from Agricultural Applications — 11 States, 1998–2006
  A study by the Centers for Disease Control and Prevention’s (CDC) National Institute for Occupational Safety and Health (NIOSH) and state agency partners finds that pesticide drift from conventional, chemical-intensive farming has poisoned thousands of farmworkers and rural residents in recent years. According to the authors, agricultural workers and residents in agricultural regions were found to have the highest rate of pesticide poisoning from drift exposure, and soil fumigations were a major hazard causing large drift incidents. Daily News
  [Lee, SJ. et al. 2011. Environ Health Perspect. 119:1162–1169]
• Repeated pesticide exposure among North Carolina migrant and seasonal farmworkers
  Data were collected from 196 farmworkers four times at monthly intervals in 2007. Urine samples were tested for 12 pesticide urinary metabolites. Farmworkers had at least one detection for many pesticide urinary metabolites; for example, 84.2% had at least one detection for acephate, 88.8% for 3,5,6-trichloro-2-pyridinol. Most farmworkers had multiple detections for specific metabolites.
  [Arcury, T. et al. 2010. Am. J. Ind. Med. 53:802–813]
• Agreement of pesticide biomarkers between morning void and 24-h urine samples from farmers and their children
  In pesticide biomonitoring studies, researchers typically collect either single voids or daily (24-h) urine samples. Collection of 24-h urine samples is considered the "gold-standard", but this method places a high burden on study volunteers, requires greater resources, and may result in misclassification of exposure or underestimation of dose due to noncompliance with urine collection protocols. To evaluate the potential measurement error introduced by single void samples, we present an analysis of exposure and dose for two commonly used pesticides based on single morning void (MV) and 24-h urine collections in farmers and farm children. The agreement between the MV concentration and its corresponding 24-h concentration was analyzed using simple graphical and statistical techniques and risk assessment methodology. A consistent bias towards overprediction of pesticide concentration was found among the MVs, likely in large part due to the pharmacokinetic time course of the analytes in urine. These results suggest that the use of single voids can either over- or under-estimate daily exposure if recent pesticide applications have occurred. This held true for both farmers as well as farm children, who were not directly exposed to the applications. As a result, single void samples influenced the number of children exposed to chlorpyrifos whose daily dose estimates were above levels of toxicologic significance. In populations where fluctuations in pesticide exposure are expected (e.g., farm families), the pharmacokinetics of the pesticide and the timing of exposure events and urine collection must be understood when relying on single voids as a surrogate for longer time-frames of exposure.
  [Scher, D. et al. 2007, J. Exposure Science and Environmental Epidemiology;17, 350–357]
• Pesticides and their metabolites in the homes and urine of farmworker children living in the Salinas Valley, CA.
  In support of planning efforts for the National Children's Study, authors conducted a study to test field methods for characterizing pesticide exposures to 20 farmworker children aged 5-27 months old living in the Salinas Valley of Monterey County, California. Study tested methods for collecting house dust, indoor and outdoor air, dislodgeable residues from surfaces and toys, residues on clothing (sock and union suits), food, as well as spot and overnight diaper urine samples. Authors measured 29 common agricultural and home use pesticides in multiple exposure media samples. A subset of organophosphorus (OP), organochlorine (OC) and pyrethroid pesticides were measured in food. Urine samples were also analyzed. Pesticides were detected more frequently in house dust, surface wipes, and clothing than other media, with chlorpyrifos, diazinon, chlorthal-dimethyl, and cis- and trans-permethrin detected in 90% to 100% of samples. Levels of four of these five pesticides were positively correlated among the house dust, sock, and union suit samples. Pesticide loading on socks and union suits was higher for the group of 10 toddlers compared to the 10 younger crawling children. Several OP pesticides, as well as 4,4'-DDE, atrazine, and dieldrin were detected in the food samples. Future uses of these data include the development of pesticide exposure models and risk assessment.
  [Bradman A, Whitaker D, Quirós L, Castorina R, et al. 2007. J Expo Sci Environ Epidemiol;17(4):331-49]
• Paraoxonase polymorphisms, haplotypes, and enzyme activity in Latino mothers and newborns.
  Recent studies have demonstrated widespread pesticide exposures in pregnant women and in children. Plasma paraoxonase 1 (PON1) plays an important role in detoxification of various organophosphates. The goals of this study were to examine in the Center for Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort of Latina mothers and their newborns living in the Salinas Valley, California, the frequencies of five PON1 polymorphisms in the coding region (192QR and 55LM) and the promoter region (-162AG, -909CG, and -108CT) and to determine their associations with PON1 plasma levels [phenylacetate arylesterase (AREase) ] and enzyme activities of paraoxonase (POase) and chlorpyrifos oxonase (CPOase) . Authors found that PON1-909, PON1-108, and PON1(192) had an equal frequency (0.5) of both alleles, whereas PON1-162 and PON1(55) had lower variant allele frequencies (0.2) . Nearly complete linkage disequilibrium was observed among coding and promoter polymorphisms (p < 0.001) , except PON1(192) and PON1-162 (p > 0.4) . Children's PON1 plasma levels (AREase ranged from 4.3 to 110.7 U/mL) were 4-fold lower than their mothers' (19.8 to 281.4 U/mL) . POase and CPOase activities were approximately 3-fold lower in newborns than in mothers. The genetic contribution to PON1 enzyme variability was higher in newborns (R2 = 25.1% by genotype and 26.3% by haplotype) than in mothers (R2 = 8.1 and 8.8%, respectively) . However, haplotypes and genotypes were comparable in predicting PON1 plasma levels in mothers and newborns. Most of the newborn children and some pregnant women in this Latino cohort may have elevated susceptibility to organophosphate toxicity because of their PON1192 genotype and low PON1 plasma levels.
  [Holland N, Furlong C, Bastaki M, et al. 2006. Environ Health Perspect. 114(7):985-91]
• Association of in utero organochlorine pesticide exposure and fetal growth and length of gestation in an agricultural population.
  Although substantial evidence exists for the fetal toxicity of organochlorines in animals, information on human reproductive effects is conflicting. Study investigated whether infants' length of gestation, birth weight, and crown-heel length were associated with maternal serum levels of 11 different organochlorine pesticides: p,p -dichlorodiphenyltrichloroethane (p,p -DDT), p,p -dichlorodiphenyldichloroethylene (p,p -DDE), o,p -dichlorodiphenyltrichloroethane (o,p -DDT), hexachlorobenzene (HCB), gamma-hexachlorocyclohexane (gamma-HCCH), gamma-hexachlorocyclohexane (gamma-HCCH), dieldrin, heptachlor epoxide, oxychlordane, trans-nonachlor, and mirex. Our subjects were a birth cohort of 385 low-income Latinas living in the Salinas Valley, an agricultural community in California. Results found no adverse associations between maternal serum organochlorine levels and birth weight or crown-heel length. Decreased length of gestation with increasing levels of lipid-adjusted HCB was found. Study did not find reductions in gestational duration associated with any of the other organochlorine pesticides. Study's finding of decreased length of gestation related to HCB does not seem to have had clinical implications for this population, given its relatively low rate of preterm delivery (6.5%).
  [Fenster L, Eskenazi B, Anderson M, Bradman A. 2006. Environ Health Perspect. 114(4):597-602]
• Urinary and hand wipe pesticide levels among farmers and nonfarmers in Iowa
  In the spring and summer of 2001, as part of a larger study investigating farm family pesticide exposure and home contamination in Iowa, urine and hand wipe samples were collected from 24 male farmers and 23 male nonfarmer controls. The samples were analyzed for the parent compound or metabolites of six commonly used agricultural pesticides: alachlor, atrazine, acetochlor, metolachlor, 2,4-dichlorophenoxyacetic acid (2,4-D) and chlorpyrifos. For atrazine, acetochlor, metolachlor and 2,4-D, farmers who reported applying the pesticide had significantly higher urinary metabolite levels than nonfarmers, farmers who did not apply the pesticide, and farmers who had the pesticide commercially applied. Generally, there were no differences in urinary pesticide metabolite levels between nonfarmers, farmers who did not apply the pesticide, and farmers who had the pesticide commercially applied. Among farmers who reported applying 2,4-D themselves, time since application, amount of pesticide applied, and the number of acres to which the pesticide was applied were marginally associated with 2,4-D urine levels. Among farmers who reported applying atrazine themselves, time since application and farm size were marginally associated with atrazine mercapturate urine levels. Farmers who reported using a closed cab to apply these pesticides had higher urinary pesticide metabolite levels, although the difference was not statistically significant. Farmers who reported using closed cabs tended to use more pesticides. The majority of the hand wipe samples were nondetectable. However, detection of atrazine in the hand wipes was significantly associated with urinary levels of atrazine above the median.
  [Curwin, B. et al. 2005. J of Exposure Analysis and Environmental Epidemiology 15, 500–508]
• Biologic monitoring to characterize organophosphorus pesticide exposure among children and workers: an analysis of recent studies in Washington State.
  Study examined findings from five organophosphorus pesticide biomonitoring studies conducted in Washington State between 1994 and 1999 and compared urinary dimethylthiophosphate (DMTP) concentrations for all study groups and composite dimethyl alkylphosphate (DMAP) concentrations for selected groups. Children of pesticide applicators had substantially higher metabolite levels than did Seattle children and farmworker children. Metabolite levels of children living in agricultural communities were elevated during periods of crop spraying. Median DMTP concentrations for Seattle children and farmworker children did not differ significantly; however, the DMAP concentrations were higher for Seattle children than for farmworker children. DMTP concentrations of U.S. children 6-11 years of age (1999-2000 National Health and Nutrition Examination Survey population) were higher than those of Seattle children and farmworker children. DMTP concentrations for workers actively engaged in apple thinning were 50 times higher than DMTP concentrations for farmworkers sampled outside of peak exposure periods. Study concludes that workers who have direct contact with pesticides should continue to be the focus of public health interventions and that elevated child exposures in agricultural communities may occur during active crop-spraying periods and from living with a pesticide applicator. Timing of sample collection is critical for the proper interpretation of pesticide biomarkers excreted relatively soon after exposure. Authors surmise that differences in dietary exposure can explain the similar exposures observed among farmworker children, children living in the Seattle metropolitan area, and children sampled nationally.
  [Fenske RA, Lu C, Curl CL, Shirai JH, Kissel JC. 2005. Environ Health Perspect.;113(11):1651-7]
• Children’s Exposure to Chlorpyrifos and Parathion in an Agricultural Community in Central Washington State
  Authors measured two diethyl organophosphorus (OP) pesticides--chlorpyrifos and parathion--in residences, and their metabolic by-products, in the urine of children 6 years old or younger in a central Washington State agricultural community. Median chlorpyrifos house dust concentrations were highest for the 49 applicator homes (0.4 microg/g), followed by the 12 farm-worker homes (0.3 microg/g) and the 14 nonagricultural reference homes (0.1 microg/g); authors observed a similar pattern for parathion in house dust. Chlorpyrifos was measurable in the house dust of all homes, whereas parathion in only 41% of the homes was found. Child urinary metabolite concentrations did not differ across parental occupational classifications. Homes in close proximity (200 ft/60 m) to pesticide-treated farmland had higher chlorpyrifos (p = 0.01) and parathion (p = 0.014) house dust concentrations than did homes farther away, but this effect was not reflected in the urinary metabolite data. Use of OP pesticides in the garden was associated with an increase in TCPy concentrations in children's urine. Parathion concentrations in house dust decreased 10-fold from 1992 to 1995, consistent with the discontinued use of this product in the region in the early 1990s.
  [Fenske, R.A., Lu, C, Barr, D, and Needham, L. 2002. Environ Health Perspect. 11(5):: 549–553]
• Evaluation of take-home organophosphorus pesticide exposure among agricultural workers and their children.
  Researchers analyzed organophosphorus pesticide exposure in 218 farm worker households in agricultural communities in Washington State to investigate the take-home pathway of pesticide exposure and to establish baseline exposure levels for a community intervention project. House dust samples were collected from within the homes, and vehicle dust samples were collected from the vehicles used by the farm workers to commute to and from work. Urine samples were obtained from a farm worker and a young child in each household. Dust samples were analyzed for six pesticides, and urine samples were analyzed for five dialkylphosphate (DAP) metabolites. Azinphosmethyl was detected in higher concentrations than the other pesticides. Dimethyl DAP metabolite concentrations were higher than diethyl DAP metabolite concentrations in both child and adult urine. Azinphosmethyl concentrations in house dust and vehicle dust from the same household were significantly associated. Dimethyl DAP levels in child and adult urine from the same household were also significantly associated, and this association remained when the values were creatinine adjusted. The results of this work support the hypothesis that the take-home exposure pathway contributes to residential pesticide contamination in agricultural homes where young children are present.
  [Curl CL, Fenske RA, Kissel JC, et al. 2002. Environ Health Perspect;110(12):A787-92]
• Biological monitoring survey of organophosphorus pesticide exposure among pre-school children in the Seattle metropolitan area
  In this study we assessed organophosphorus (OP) pesticide exposure among children living in two Seattle metropolitan area communities by measuring urinary metabolites, and identified possible exposure risk factors through a parental interview. We recruited children in clinic and outpatient waiting rooms. We obtained spot urine samples in the spring and fall of 1998 from 110 children ages 2-5 years, from 96 households. We analyzed urine samples for six dialkylphosphate (DAP) compounds, the common metabolites of the OP pesticides. Through parental interviews we gathered demographic and residential pesticide use data. At least one of the DAP metabolites was measured in 99% of the children, and the two predominant metabolites (DMTP and DETP) were measured in 70-75% of the children. We found no significant differences in DAP concentrations related to season, community, sex, age, family income, or housing type. Median concentrations of dimethyl and diethyl DAPs were 0.11 and 0.04 micromol/L, respectively (all children). Concentrations were significantly higher in children whose parents reported pesticide use in the garden (0.19 vs. 0.09 micromol/L for dimethyl metabolites, p = 0.05; 0.04 vs. 0.03 micromol/L for diethyl metabolites, p = 0.02), but were not different based on reported pet treatment or indoor residential use. Nearly all children in this study had measurable levels of OP pesticide metabolites. Some of this exposure was likely due to diet. Garden pesticide use was associated with elevated metabolite levels. It is unlikely that these exposure levels would cause acute intoxication, but the long-term health effects of such exposures are unknown. We recommend that OP pesticide use be avoided in areas where children are likely to play.
  [Lu C, Knutson DE, Fisker-Andersen J, Fenske RA. 2001. Environ Health Perspect;109(3):299-303]
• Biological monitoring of organophosphorus pesticide exposure among children of agricultural workers in central Washington State.
  Children up to 6 years of age who lived with pesticide applicators were monitored for increased risk of pesticide exposure: 48 pesticide applicator and 14 reference families were recruited from an agricultural region of Washington State in June 1995. A total of 160 spot urine samples were collected from 88 children, including repeated measures 3-7 days apart. Dimethylthiophosphate (DMTP) was the dominant metabolite and levels were significantly higher in applicator children than in reference children, with median concentrations of 0.021 and 0.005 microg/ml, respectively; maximum concentrations were 0.44 and 0.10 microg/ml, respectively. Percentages of detectable samples were 47% for applicator children and 27% for reference children. A marginally significant trend of increasing concentration was observed with decreasing age among applicator children, and younger children within these families had significantly higher concentrations when compared to their older siblings. Applicator children living less than 200 feet from an orchard were associated with higher frequency of detectable DMTP levels than nonproximal applicator children. These results indicate that applicator children experienced higher organophosphorus pesticide exposures than did reference children in the same community and that proximity to spraying is an important contributor to such exposures. Trends related to age suggest that child activity is an important variable for exposure. It is unlikely that any of the observed exposures posed a hazard of acute intoxication. This study points to the need for a more detailed understanding of pesticide exposure pathways for children of agricultural workers.
  [Loewenherz C, Fenske RA, Simcox NJ, Bellamy G, Kalman D. 1997. Environ Health Perspect.;105(12):1344-53]
• Biomonitoring of exposure in farmworker studies
  Although biomonitoring has been used in many occupational and environmental health and exposure studies, we are only beginning to understand the complexities and uncertainties involved with the biomonitoring process--from study design, to sample collection, to chemical analysis--and with interpreting the resulting data. Author presents an overview of concepts that should be considered when using biomonitoring or biomonitoring data, assess the current status of biomonitoring, and detail potential advancements in the field that may improve our ability to both collect and interpret biomonitoring data. Author also discusses issues such as the appropriateness of biomonitoring for a given study, the sampling time frame, temporal variability in biological measurements to nonpersistent chemicals, and the complex issues surrounding data interpretation. In addition, we provide recommendations to improve the utility of biomonitoring in farmworker studies.
  [Barr DB, et al. 2006. Environ Health Perspect.;114(6):936-42]
• Pesticides in household dust and soil: exposure pathways for children of agricultural families.

  Child of agriculture families are likely to be exposed to agricultural chemicals, even if they are not involved in farm activities. This study was designed to determine whether such children are exposed to higher levels of pesticides than children whose parents are not involved in agriculture and whose homes are not close to farms. Household dust and soil samples were collected in children's play areas from 59 residences in eastern Washington State (26 farming, 22 farmworker, and 11 nonfarming families). The majority of the farm families lived within 200 feet of an operating apple or pear orchard, whereas all reference homes were located at least a quarter of a mile from an orchard. Four organophosphorous (OP) insecticides commonly used on tree fruit were targeted for analysis: azinphosmethyl, chlorpyrifos, parathion, and phosmet. Pesticide concentrations in household dust were significantly higher than in soil for all groups. OP levels for farmer/farm-worker families ranged from nondetectable to 930 ng/g in soil (0.93 ppm) and from nondetectable to 17,000 ng/g in dust (17 ppm); all four OP compounds were found in 62% of household dust samples, and two-thirds of the farm homes contained at least one OP above 1000 ng/g.These results demonstrate that children of agricultural families have a higher potential for exposure to OP pesticides than children of nonfarm families in this region. Children's total and cumulative exposure to this pesticide class from household dust, soil, and other sources warrants further investigation.
  [Simcox N.J., Fenske, R.A, Wolz. S.A, Lee, I.C, and Kalman, D.A. 1995. Environ Health Perspect. 103(12):1126-34.]

Obesity

• The association between urinary concentrations of dichlorophenol pesticides and obesity in children
  This study was conducted to assess the association of exposure to environmental pesticides with childhood obesity.A total of 6770 subjects aged 6-19 years were selected from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey (NHANES). Exposure to environmental pesticides was determined based on the concentrations of pesticide residues in urine. A dose-dependent increase in prevalence of obesity was observed in the groups with inter-quartile urinary concentrations of 2,5-dichlorophenol (2,5-DCP). There was a significant association between urinary 2,5-DCP levels and childhood obesity. However, urinary concentrations of 2,4-dichlorophenol were not shown to be significantly associated with childhood obesity. This study suggests a possible relationship between exposure to 2,5-DCP and obesity in children.
  [Twum, C. and Wei. Y. 2011. Reviews on Environ Health.26(3): 215–219.]
  
• Low dose organochlorine pesticides and polychlorinated biphenyls predict obesity, dyslipidemia, and insulin resistance among people free of diabetes
  The current study examined if low dose POPs predicted future adiposity, dyslipidemia, and insulin resistance among controls without diabetes in that study. 90 controls were diabetes-free during 20 years follow-up. They were a stratified random sample, enriched with overweight and obese persons. POPs measured in 1987-88 (year 2) sera included 8 organochlorine (OC) pesticides, 22 polychlorinated biphenyls (PCBs), and 1 polybrominated biphenyl (PBB). Body mass index (BMI), triglycerides, HDL-cholesterol, LDL-cholesterol, and homeostasis model assessment value for insulin resistance (HOMA-IR) were study outcomes at 2005-06 (year 20). Parallel to prediction of type 2 diabetes, many statistically significant associations of POPs with dysmetabolic conditions appeared at low dose, forming inverted U-shaped dose-response relations. Among OC pesticides, p,p'-DDE most consistently predicted higher BMI, triglycerides, and HOMA-IR and lower HDL-cholesterol at year 20 after adjusting for baseline values. Simultaneous exposure to various POPs in the general population may contribute to development of obesity, dyslipidemia, and insulin resistance, common precursors of type 2 diabetes and cardiovascular diseases. Although obesity is a primary cause of these metabolic abnormalities, POPs exposure may contribute to excess adiposity and other features of dysmetabolism.
  [Lee, D.H., Steffes, M., Sjödin, A., et al. 2011. PLoS ONE. 6: e15977.]
• Does early-life exposure to organophosphate insecticides lead to prediabetes and obesity
  Researchers gave neonatal rats chlorpyrifos, diazinon or parathion in doses devoid of any acute signs of toxicity, straddling the threshold for barely-detectable cholinesterase inhibition. Organophosphate exposure during a critical developmental window altered the trajectory of hepatic adenylyl cyclase/cyclic AMP signaling, culminating in hyperresponsiveness to gluconeogenic stimuli. Consequently, the animals developed metabolic dysfunction resembling prediabetes. When the organophosphate-exposed animals consumed a high fat diet in adulthood, metabolic defects were exacerbated and animals gained excess weight compared to unexposed rats on the same diet. At the same time, the high fat diet ameliorated many of the central synaptic defects caused by organophosphate exposure, pointing to nonpharmacologic therapeutic interventions to offset neurodevelopmental abnormalities, as well as toward fostering dietary choices favoring high fat intake. These studies show how common insecticides may contribute to the increased worldwide incidence of obesity and diabetes.
  [Slotkin, T.A. 2011. Reproductive Toxicology. 31: 297–301.]
• Obesity and Persistent Organic Pollutants: Possible Obesogenic Effect of Organochlorine Pesticides and Polychlorinated Biphenyls
  This study aims to assess the associations between serum levels of persistent organic pollutants (POPs) and the prevalence of obesity in a cohort of obese and lean adult men and women. POP serum samples were investigated cross-sectionally in 98 obese and 47 lean participants, aged ≥18 years. Serum samples were analyzed for the presence of polychlorinated biphenyl (PCB) congeners and for the organochlorine pesticides, dichloro-diphenyl-dichloroethylene (pp-DDE), and β-hexachlorocyclohexane (βHCH). Authors established a significant negative correlation between BMI, waist, fat mass percentage, total and subcutaneous abdominal adipose tissue, and serum levels of PCB and the sumPCBs. For βHCH, authors demonstrated a positive correlation with BMI, waist, fat mass percentage, and total and subcutaneous abdominal adipose tissue. A strong correlation was established between all POP serum levels and age. Combined, these results suggest that the diabetogenic effect of low-dose exposure to POPs might be more complicated than a simple obesogenic effect.
  [Dirinck, E., Jorens,P., Covaci, A., Geens, T., et al. 2010. Obesity. 19: 709–714.]

GMOs

Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada
Study analyzed blood samples for 39 nonpregnant women and 30 pregnant woman and their fetuses and finds pesticides associated with genetically engineered (GE) foods are present in maternal, fetal and nonpregnant women’s blood. Baccillus thuringiensis (Bt) was detected in 93% of maternal blood samples, 80% of fetal blood samples and 69% of the nonpregnant women’s blood. Glufosinate was detected in 18% of nonpregnant women’s blood but not detected in maternal and fetal blood. It’s metabolite, 3-mehtylphosphinicopropionic acid (3-MPPA), however, was detected in 100% of maternal and umbilical cord blood samples and in 67 % of the nonpregnant women’s blood. Visit the Genetic Engineering page and Daily News.

Wildlife

Diamondback terrapins as indicator species of persistent organic pollutants: Using Barnegat Bay, New Jersey as a case study
The diamondback terrapin's (Malaclemys terrapin) wide geographic distribution, long life span, occurrence in a variety of habitats within the saltmarsh ecosystem, predatory foraging behavior, and high site fidelity make it a useful indicator species for contaminant monitoring in estuarine ecosystems. In this study fat biopsies and plasma samples were collected from males and females from two sites within Barnegat Bay, New Jersey, as well as tissues from a gravid female and blue mussels (Mytilus edulis), which are terrapin prey. Samples were analyzed for persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), chlorinated pesticides, and methyl-triclosan. Terrapins from the northern site, Spizzle Creek, closest to influences from industrial areas, had higher POP concentrations for both tissues than terrapins from the less impacted Forsythe National Wildlife Refuge. Sex differences were observed with males having higher contaminant concentrations in fat and females in plasma. PCB patterns in terrapin fat and plasma were comparable to other wildlife. Plasma contaminant concentrations significantly and positively correlated with those in fat. This study addresses several aspects of using the terrapin as an indicator species for POP monitoring: site and sex differences, tissue sampling choices, maternal transfer, and biomagnification.
[Basile ER, Avery HW, Bien WF, Keller JM. 2011. Chemosphere. 82(1):137-44]

• Incidence of organochlorine pesticides and the health condition of nestling ospreys (Pandion haliaetus) at Laguna San Ignacio, a pristine area of Baja California Sur, Mexico.
  Researchers identified and quantified organochlorine (OC) pesticide residues in the plasma of 28 osprey (Pandion haliaetus) nestlings from a dense population in Laguna San Ignacio, a pristine area of Baja California Sur, Mexico, during the 2001 breeding season. Sixteen OC pesticides were identified and quantified. a-, ß-, d- and ?-hexachlorocyclohexane, heptaclor, heptachlor epoxide, endosulfan I and II, endosulfan-sulfate, p,p'-DDE, p,p'-DDD, aldrin, dieldrin, endrin, endrin aldehyde, and endrin ketone were the OCs found in the plasma of nestlings, ranging from 0.002 to 6.856 pg/µl (parts per billion). No differences were found in the concentration of pesticides between genders (P > 0.05). In this work, the concentrations detected in the plasma were lower than those reported to be a threat for the species and that affect the survival and reproduction of birds. The presence of OC pesticides in the remote Laguna San Ignacio osprey population is an indication of the ubiquitous nature of these contaminants. OCs are apparently able to travel long distances from their source to the study area. A significant relationship between hemoglobin and mean corpuscular hemoglobin concentrations and OC concentrations were found suggesting that a potential effect on the health of chicks may exist in this osprey population caused by the OC, e.g. anemia. The total proteins were positively correlated with a-BHC, endosulfan I, and p,p'-DDD. It has been suggested that OC also affects competitive interactions and population status over the long term in vertebrate species, and these results could be used as reference information for comparison with other more exposed osprey populations.
  [Rivera-Rodríguez LB, Rodríguez-Estrella R. 2011. Ecotoxicology.;20(1):29-38]
• Partitioning of persistent organic pollutants between blubber and blood of wild bottlenose dolphins: implications for biomonitoring and health
  Biomonitoring surveys of wild cetaceans commonly utilize blubber as a means to assess exposure to persistent organic pollutants (POPs), but the relationship between concentrations in blubber and those in blood, a better indicator of target organ exposure, is poorly understood. To define this relationship, matched blubber and plasma samples (n = 56) were collected from free-ranging bottlenose dolphins (Tursiops truncatus) and analyzed for 61 polychlorinated biphenyl (PCB) congeners, 5 polybrominated diphenyl ether (PBDE) congeners, and 13 organochlorine pesticides (OCPs). With the exception of PCB 209, lipid-normalized concentrations of the major POPs in blubber and plasma were positively and significantly correlated (R(2) = 0.828 to 0.976). Plasma concentrations, however, significantly increased with declining blubber lipid content, suggesting that as lipid is utilized, POPs are mobilized into blood. Compound- and homologue- specific blubber/blood partition coefficients also differed according to lipid content, suggesting POPs are selectively mobilized from blubber. Overall, these results suggest that with the regression parameters derived here, blubber may be used to estimate blood concentrations and vice versa. Additionally, the mobilization of lipid from blubber and concomitant increase in contaminants in blood suggests cetaceans with reduced blubber lipid may be at greater risk for contaminant-associated health effects.
  [Yordy JE, Wells RS, Balmer BC, Schwacke LH, Rowles TK, Kucklick JR. 2010. Environ Sci Technol. 15;44(12):4789-95]
• Flame retardants and organochlorine pollutants in bald eagle plasma from the Great Lakes region
  Study reports measurements of polybrominated diphenyl ethers and of emerging flame retardants in the plasma of nestling bald eagles sampled from early May to late June of 2005. Concentrations of total PBDEs ranged from 0.35 ng g(-1) ww to 29.3 ng g(-1) ww. Several emerging flame retardants, such as pentabromoethylbenzene (PBEB), hexabromocyclododecanes (HBCDs), and Dechlorane Plus (DP), were detected in these samples. Polychlorinated biphenyls (PCBs) and organochlorine pesticides were also detected at levels close to those previously published. A statistically significant relationship was found between total PBDE concentrations and total PCB and p,p'-DDE concentrations, suggesting that these compounds share a common source, which is most likely the eagle's food.
  [Venier M. et al. 2010. Chemosphere.80(10):1234-40]
• Concentrations in bird feathers reflect regional contamination with organic pollutants.
  Feathers have recently been shown to be potentially useful non-destructive biomonitoring tools for organic pollutants. However, the suitability of feathers to monitor regional variations in contamination has not been investigated until now. Here concentrations of organic pollutants were compared in feathers of common magpies (Pica pica) between urban and rural areas in Flanders, Belgium. The results showed that concentrations of p,p'-dichlorodiphenyldichloroethylene (DDE) were significantly higher in the rural areas, while polychlorinated biphenyls (PCBs) were significantly more available in an urban environment. This pattern agrees with previous studies using other tissues than feathers as a biomonitoring tool. In addition, differences in PCBs and PBDEs profiles were found with lower halogenated congeners being more prominent in the urban areas in comparison to the rural areas. In summary, feathers seem to reflect regional variations in contamination, which strengthens their usefulness as a non-destructive biomonitor for organic pollutants.
  [Jaspers VL, Covaci A, Deleu P, Eens M. 2009. Sci Total Environ;407(4):1447-51]
• Chiral organochlorine contaminants in blood and eggs of glaucous gulls (Larus hyperboreus) from the Norwegian Arctic.
  Glaucous gulls (Larus hyperboreus) and their eggs from Svalbard (Norwegian Arctic) have been used as biomonitors of contaminants in the marine environment. In this study, the enantiomer fractions (EFs) of chiral chlordanes and atropisomeric polychlorinated biphenyl (PCB) congeners were determined in the blood plasma of adult male and female glaucous gulls from three breeding colonies in Svalbard. Plasma EFs were similar in magnitude and direction to EFs previously reported in glaucous gulls from other arctic food webs, suggesting overall similarities in the biochemical processes influencing the EFs of bioaccumulated organochlorine (OC) contaminants within the food webs at those locations. Additionally, EFs in yolk of eggs collected concurrently from within the same nesting colonies varied with location, laying date, and OC concentrations, and may be influenced by changes in the local feeding ecology between those colonies. The use of eggs as a valuable and noninvasive means of OC biomonitoring may also extend to enantiomer compositions in glaucous gulls, and perhaps also in other seabird species from arctic regions.
  [Ross MS, Verreault J, Letcher RJ, Gabrielsen GW, Wong CS. 2008. Environ Sci Technol.;42(19):7181-6]
• Can predatory bird feathers be used as a non-destructive biomonitoring tool of organic pollutants?
  The monitoring of different types of pollutants that are released into the environment, and that present risks for both humans and wildlife have become increasingly important. In this study, authors examined whether feathers of predatory birds can be used as a non-destructive biomonitor of organic pollutants. Study demonstrates that polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and polybrominated diphenyl ethers (PBDEs) are measurable in one single tail feather of common buzzards (Buteo buteo) and that levels in this feather and internal tissues are significantly related to each other. Findings provide the first indication that feathers of predatory birds could be useful in non-destructive biomonitoring of organic pollutants, although further validation may be necessary.
  [Jaspers, V,L. et al. 2006. Biol. Lett. 2, 283-285]
• Organochlorine chemical residues in fish from the Mississippi River basin, 1995.
  Fish were collected in late 1995 from 34 National Contaminant Biomonitoring Program (NCBP) stations and 13 National Water Quality Assessment Program (NAWQA) stations in the Mississippi River basin (MRB) and in late 1996 from a reference site in West Virginia. Four composite samples, each comprising (nominally) 10 adult common carp (Cyprinus carpio) or black bass (Micropterus spp.) of the same sex, were collected from each site and analyzed for organochlorine chemical residues. At the NCBP stations, which are located on relatively large rivers, concentrations of organochlorine chemical residues were generally lower than when last sampled in the mid-1980s. Residues derived from DDT (primarily p,p'-DDE) were detected at all sites (including the reference site); however, only traces of the parent insecticide (p,p'-DDT) were present, which indicates continued weathering of residual DDT from past use. Nevertheless, concentrations of DDT (as p,p'-DDE) in fish from the cotton-farming regions of the lower MRB were great enough to constitute a hazard to fish-eating wildlife and were especially high at the NAWQA sites on the lower-order rivers and streams of the Mississippi embayment. Mirex was detected at only two sites, both in Louisiana, and toxaphene was found exclusively in the lower MRB. Most cyclodiene pesticides (dieldrin, chlordane, and heptachlor epoxide) were more widespread in their distributions, but concentrations were lower than in the 1980s except at a site on the Mississippi River near Memphis, TN. Concentrations were also somewhat elevated at sites in the Corn Belt. Endrin was detected exclusively at the Memphis site. PCB concentrations generally declined, and residues were detected at only 35% of the stations, mostly in the more industrialized parts of the MRB.
  [Schmitt CJ. 2002. Arch Environ Contam Toxicol.;43(1):81-97]