(Beyond Pesticides, January 31, 2012) The Environmental Protection Agency (EPA) has proposed an expansion in pyrethrins/pyrethroid insecticide uses as part of its cumulative risk assessment for this neurotoxic class of chemicals. In the cumulative risk assessment, EPA concludes that pyrethroids ‚Äúdo not pose risk concerns for children or adults,‚ÄĚ ignoring a wealth of independent data that links this class of chemicals to certain cancers, respiratory and reproductive problems, and the onset of insect resistance. It went as far as to state that its cumulative assessment supports consideration of registering additional new uses of these pesticides, potentially opening the flood gates for manufacturers to bombard the market with more pyrethroid pesticides, endangering the health of the public. The agency is accepting public comments through February 8, 2012. Tell EPA that it has ignored numerous health effects and that these pesticides do pose unacceptable risks to human health given the availability of alternatives. Submit comments directly to the EPA docket or sign-on to Beyond Pesticides’ comments.
In its comments to EPA, Beyond Pesticides states:
There are several major concerns and flaws plaguing this cumulative assessment, which therefore does not meet the regulatory burden in fully evaluating synthetic pyrethroids‚Äô effect on public and environmental health. We are troubled that EPA‚Äôs analysis and conclusions allow the expanded use of synthetic pyrethroids, despite the known adverse effects associated with exposures and the high degree of uncertainty associated with multiple adverse endpoints. The most egregious conclusion of this assessment is the reduction of the FQPA safety factor from 10x to 3x for children under six years of age and 1X for persons over six years old, including pregnant women. Given that some members of this chemical class are probable carcinogens and endocrine disruptors, and may suppress the immune system, endpoints that EPA has not sufficiently taken into consideration, it is not appropriate for the agency to reduce the FQPA safety factor at this time. The agency further states that cumulative estimated risks from existing pyrethroid uses are not of concern, and that there is sufficient room in the pyrethroid cumulative ‚Äėrisk cup‚Äô to support consideration of new pyrethroids and new uses. The agency violates its statutory duty under the ‚Äúunreasonable adverse effect‚ÄĚ provision of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) in welcoming the proliferation of this class of insecticides when it has been shown to be associated with a host of acute and chronic health problems, and the contamination of homes and terrestrial and aquatic environments. Not fully evaluated in the assessment is the rise of insect resistance to the chemicals, inevitable with elevated use and exposure.
One of the most troubling aspects of EPA’s risk assessment is its decision to reduce the Food Quality Protection Act (FQPA) protective safety factor from 10X (an additional margin of safety of 10 times) to 1X for children and adults over six years, and to 3X for children under six years of age. The FQPA safety factor is intended to protect infants and children to account for their special vulnerability to pesticides, taking into account the potential for pre- and post-natal toxicity. Given that children are especially sensitive to the effects of synthetic pyrethroids like permethrin, this reduction in the special safety factor is egregious. Studies have found that certain pyrethoids like permethrin are almost five times more toxic to the young compared to adults, and in sensitive individuals the difference is even greater. Additionally, studies have shown that permethrin may inhibit neonatal brain development. In this new cumulative risk assessment, the agency even states, ‚ÄúBased on pharmacokinetic data, there is evidence that indicates an increase in sensitivity to pyrethroids of the young compared to adults,‚ÄĚ which is attributed to the difference in the ability of the adults and juveniles to metabolize pyrethroids. EPA‚Äôs modeling data also predict a 3-fold increase of pyrethroid concentrations in juvenile brains compared to adults. Similarly, researchers at Emory University and the Centers for Disease Control and Prevention (CDC) in a published study conclude that residential pesticide use represents the most important risk factor for children‚Äôs exposure to pyrethroid insecticides. Despite all this, EPA chooses to forgo this evidence and green light more uses of pyrethroid chemicals which will inevitably impact more vulnerable children.
With the phase-out of most residential uses of the common organophosphate insecticides, home use of pyrethroids has increased. Pesticide products containing synthetic pyrethroids are often described by pest control operators and community mosquito management bureaus as ‚Äúsafe as chrysanthemum flowers.‚ÄĚ While pyrethroids are a synthetic version of an extract from the chyrsanthemum plant, they are chemically engineered to be more toxic, take longer to break down, and are often formulated with synergists, increasing potency, and compromising the human body‚Äôs ability to detoxify the pesticide.
As a consequence of their widespread use, many pests -such as bed bugs- are now becoming resistant to pyrethroids. A recent study shows that modern bed bugs have developed the ability to defend themselves against pyrethroid pesticides, with a required dosage of as much as 1,000 times the amount that should normally be lethal, due in part to the widespread use of such treatment methods. Due to the ability of these organisms to develop resistance to chemical agents, exposing these bugs to more pesticides would lead to higher rates of resistance among insect populations, a point that EPA does not acknowledge.
EPA is mandated to complete cumulative risk assessments for chemicals that have the same mechanism of toxicity. In 2009, EPA conceded that pyrethroid chemicals did in fact have a common mechanism of toxicity. In this risk assessment, not all pyrethroids were evaluated and various routes of exposures, such as dermal and inhalation exposures, were not adequately examined, with the agency stating that these exposures ‚Äúgenerally do not significantly contribute to the overall risk picture,‚ÄĚ even though numerous pyrethroid formulations of ‚Äėapply to skin‚Äô mosquito repellent and indoor bug sprays are widely available.
Pyrethroids are a widely used class of insecticides used for mosquito control and various insects in residential and agricultural settings. This class of chemicals includes permethrin, bifenthrin, resmethrin, cyfluthrin and scores of others. Exposure to synthetic pyrethroids has been reported to lead to headaches, dizziness, nausea, irritation, and skin sensations. There are also serious chronic health concerns related to synthetic pyrethroids. EPA classifies permethrin and cypermethrin as possible human carcinogens, based on evidence of lung tumors in lab animals exposed to these chemicals. EPA also lists permethrin as a suspected endocrine disruptor. Synthetic pyrethroids have also been linked to respiratory problems such as hypersensitization, and may be triggers for asthma attacks. Material Safety Data Sheets, issued by the Occupational Safety and Health Administration (OSHA), for pyrethroid products often warn, ‚ÄúPersons with history of asthma, emphysema, and other respiratory tract disorders may experience symptoms at low exposures.‚ÄĚ Pyrethroids are persistent and are making their way into human bodies at alarming rates. CDC ‚Äės Fourth National Report on Human Exposure to Environmental Chemicals reports that widely used pyrethroids are found in greater than 50% of the subjects tested.
In addition to human health effects, which this cumulative risk assessment addresses, pyrethroids are also persistent in the environment and adversely impact non-target organisms. A 2008 survey found pyrethroid contamination in 100 percent of urban streams sampled in California. Researchers also find pyrethroid residues in California streams, although at relatively low concentrations (10-20 parts per trillion) in river and creek sediments that are toxic to bottom dwelling fish. Other studies find pyrethroids present in effluent from sewage treatment plants at concentrations just high enough to be toxic to sensitive aquatic organisms.
At the same time, there are clear established methods for managing homes and schools that prevent infestation of unwanted insects without the use of synthetic chemicals, including exclusion techniques, sanitation and maintenance practices, as well as mechanical and least toxic controls (which include boric acid and diatomaceous earth). Based on the host of health effects linked to this chemical class, an increase in synthetic pyrethroid use is hazardous and unnecessary.
Take Action: Tell EPA that more uses of pyrethroids is hazardous and unnecessary. Submit comments directly to EPA‚Äôs docket or sign onto Beyond Pesticides‚Äô comments by signing this petition. We will include all organizational sign-ons when we submit the comments to EPA and keep all signatories in the loop on this issue.