(Beyond Pesticides, September 14, 2010) A new study confirms that indoor uses of consumer products, including pesticides, are the primary sources of indoor exposure to endocrine disruptors â€“chemicals that disrupt hormones and cause adverse developmental, disease, and reproductive problemsâ€“ and shows that indoor levels are higher than those outdoors. Researchers from Silent Spring Institute, Columbia University, and the University of California-Berkeley measured airborne concentrations of endocrine disruptors in two California communities: Bolinas, a rural, affluent coastal town, and Richmond, a working-class city ringed by oil refineries. The study is published online in the September 1, 2010 issue of Environmental Science & Technology.
The researchers analyzed 104 chemicals in 50 homes, including both chemicals that penetrate indoors from outdoor industrial and transportation sources and those from indoor use of consumer products and building materials. Similar levels of contamination were found inside homes in both communities, but outdoor levels were higher in Richmond. Among the chemicals found were pesticides, phthalates, parabens, PBDE flame retardants, and PCBs.
A total of 38 pesticides are evaluated, including banned organochlorines (e.g., DDT, PCP), and current use products such as carbamates (e.g., propoxur), organophosphates (e.g., chlorpyrifos), and pyrethroids (cypermethrin). Thirteen pesticides were detected outdoors and sixteen pesticides were detected in indoor air.
Unlike industrial and transportation pollutants and agricultural pesticides, which vary greatly by geographic region, the authors note that pollutants from consumer products do not vary widely geographically or demographically. This is significant because it shows the pervasive effects of common consumer products on indoor air quality.
The endocrine system consists of a set of glands (thyroid, gonads, adrenal and pituitary) and the hormones they produce (thyroxine, estrogen, testosterone and adrenaline), which help guide the development, growth, reproduction, and behavior of animals, including humans. Hormones are signaling molecules, which travel through the bloodstream and elicit responses in other parts of the body.
Endocrine disruptors function by: (i) Mimicking the action of a naturally-produced hormone, such as estrogen or testosterone, thereby setting off similar chemical reactions in the body; (ii) Blocking hormone receptors in cells, thereby preventing the action of normal hormones; or (iii) Affecting the synthesis, transport, metabolism and excretion of hormones, thus altering the concentrations of natural hormones. Endocrine disruptors have been linked to attention deficit hyperactivity disorder (ADHD), Parkinsonâ€™s and Alzheimerâ€™s diseases, diabetes, cardiovascular disease, obesity, early puberty, infertility and other reproductive disorders, and childhood and adult cancers.
More than 50 pesticide active ingredients (see the list on page 2) have been identified as endocrine disruptors by the European Union and endocrine disruptor expert Theo Colborn, PhD. Endocrine disruption is the mechanism for several health effect endpoints.
For more information on pesticides and endocrine disruption, see Beyond Pesticidesâ€™ Endocrine Disruptors brochure. To learn more about the links between pesticide exposure and a wide range of health effects, see the Pesticide-Induced Diseases Database.