What's wrong with our nation's approach to regulating pesticides

Pesticides are regulated much more strictly than industrial chemicals under U.S. law, requiring a significant amount of safety data before being registered for use, and undergoing a registration review process every 15 years in case new data on potential harm has come to light. Nonetheless, there are weaknesses, loopholes, and flaws in all aspects of the process from legal requirements to implementation to enforcement and oversight. Here I've put together some of the most endemic widespread and fundamental weaknesses with the process, in the hopes that they can be addressed by the Office of Pesticide Programs (OPP) staff at the Environmental Protection Agency (EPA).

Failure to test for known risks

Pesticide manufacturers (registrants) are required to supply a significant amount of safety data on their products to the government before their products can be registered, including acute, chronic, sub-chronic, and ecological toxicity tests on multiple species and both sexes, as well as basic chemistry data.[i] Nonetheless, most legal limits for pesticides are based on “toxic ignorance”, not on safety. That is, toxicity studies required to register a pesticide do not include many disease endpoints such as immune system toxicity, endocrine or hormone system disruptions, learning deficits, or chronic diseases such as Parkinson’s Disease. Yet, all of these have been linked to pesticide exposure in the peer-reviewed scientific literature (see reviews here and here).[ii]  Further, pesticides are only reviewed every fifteen years, leaving long lag times between science and regulations.

Register now, test later: The problem of conditional registrations

An analysis by NRDC revealed that the majority of pesticide products are approved for use as a ‘conditional registration’ before all required studies are completed (see NRDC comments on nanosilver here).[iii] Completion and review of these studies may occur years later, if at all, with little public oversight.

Industry science versus academic science

The truth is that when new studies are published that indicate the need for more protective exposure limits, the pesticide labels are stuck in time. This is because the exposure limits are set based on the data supplied by the industry (the registrant). This restrictive and biased use of science is defended by industry claims that only the industry data is conducted according to pre-validated study designs required for the registration process and performed in Good Laboratory Practices (GLP)-certified labs.[iv]  However, study designs are often very outdated and do not reflect the current science, most sensitive disease endpoints, or chronic disease outcomes. Moreover, GLP standards were imposed on industry labs during the 1970’s after flagrant violations and fraud were identified.[v] GLP requirements are designed to set a baseline of cleanliness, animal care, and record-keeping; they are not associated with higher quality research, proper study design or correct statistical analysis. In contrast, academic research which has found pesticides to be harmful has been published in respected scientific journals and relies on the peer-review process and public accessibility to uphold scientific quality.

Failure to promote reduced risk alternatives

When registering pesticides, there is no requirement for EPA to consider reduced risk or non-toxic alternatives or lower use/exposure levels.  While registrants have an incentive to approval the greatest potential uses of their product, EPA does not assess the availability of safer alternatives when considering product registration.

Failure to regulate to reduce over-use

The amount of pesticide residue that is legally allowed on our food, called a ‘tolerance’ is set based on how much pesticide a person can ‘safely’ consume and still meet the EPA standard of ‘reasonable certainty of no harm’, considering aggregate (from other uses of the same pesticide) and cumulative (uses of other pesticides in the same mode of action family) exposures. This may be much higher than a pesticide needs to be to have its desired pesticidal effect. It is likely that pesticides most could be used in far less amounts and still be effective. Unfortunately, this is not in the interests of the companies that manufacture and sell the pesticide, and negotiate the registration with EPA.

History of post-market recalls after decades of harm

As we learn more about the harmful effects of pesticides, ones that had been approved may later be restricted or even cancelled. For example, in June, 2010, after many years of public comments and even a petition and a lawsuit by NRDC, endosulfan, a highly persistant toxic pesticide is finally being cancelled due to its “unacceptable neurological and reproductive risks to farmworkers and wildlife” according to the EPA (see my blog here).[vi] Unfortunately, these actions come after decades of harmful use. Other examples are:  

  • Chlorpyrifos:  Scientific studies have reported that exposure to chlorpyrifos during pre-birth and early life stages is associated with poor birth outcomes and long-term neurobehavioral deficits. For these reasons, since 2001, residential uses of chlorpyrifos were all cancelled, resulting in a reduction of over 6 million pounds annually from people’s homes. This action has been associated with a 66% reduction in poisonings since 1995. However, approximately 10 million pounds are still used annually on corn, in orchards, and on other vegetable row crops. Its breakdown products have been detected in the bodies of three-quarters of the US population.
  • Diazinon: The phase-out of over 11 million pounds annually of non-agricultural uses of diazinon took ¾ of diazinon off the market. This was correlated with a measurable reduction of diazinon in streams of between 20 and 40%, according to government geological survey data. Unfortunately, although EPA cancelled all non-agricultural uses of diazinon (11 million pounds annually), it left agricultural uses that total approximately 3 million pounds annually.

Failure to consider farm children

Farm children, especially the children of farmworkers, come in contact with pesticides through residues from their parents’ skin and clothing, soil and dust tracked into their homes, contaminated soil and other surfaces in areas where they play, food eaten directly from the fields, drift from agricultural pesticide applications, contaminated well water, and breast milk from exposed parents (see for example here and here.[vii] In December, 2009 EPA proposed a policy to consider the unique risks to the children of farmworkers. However, as of January, 2011 this policy has still not been finalized.[viii]

Illegal uses

All of the above limitations in pesticide regulations presume legal use of pesticides. However, we know that illegal uses take place routinely, albeit not always intentionally; for example, the use of old stores of pesticides that have since been banned, or the use of pesticides according to last year’s practices even though current labels have been updated to reflect that application rates have been lowered or buffer zones have been increased. Many stores and small outlets sell pesticides that have been banned, or maybe that have never been legal in the US, for residential uses including folk remedies and other off-label illegal applications.[ix] These uses of pesticides can be dangerous, and even deadly.

[i] A summary of data required to register pesticides is here: http://www.epa.gov/opp00001/regulating/data_requirements.htm

[ii] An overview of health effects associated with pesticides is provided in the introductory remarks and study findings of the NIH Agriculture Health Study here: http://aghealth.nci.nih.gov/

See also Marina Bjørling-Poulsen et al Env Health 2008 http://www.ehjournal.net/content/7/1/50

[iii] Comments from the NRDC on the proposed conditional registration of a pesticide product HeiQ AGS-20, containing nanosilver. Sept 10, 2010. Docket ID # EPA-HQ-OPP-2009-1012

[iv] Comment from Dow Chemical company on why industry data is trustworthy: http://www.dow.com/productsafety/faq/process.htm

[v] History of GLP here: http://www.labcompliance.com/tutorial/glp/default.aspx#history

[vi] Jennifer Sass’s blog. EPA cancelling toxic pesticide, endosulfan. June 9, 2010. http://switchboard.nrdc.org/blogs/jsass/epa_cancels_endosulfan.html

[vii] Bradman A, Harnly ME, Draper W, Seidel S, Teran S, Wakeham D, Neutra R  1997. Pesticide exposure to children from California’s Central Valley: results of a pilot study. J. Expo. Anal. Environ. Epidemiol. 7, 217-234

See also Fenske et al, EHP 2002

[viii] EPA-HQ-OPP-2009-0889-0002

[ix] See the EPA website on illegal pesticide products available for sale in the U.S.: http://www.epa.gov/opp00001/health/illegalproducts/

About the Authors

Jennifer Sass

Senior Scientist, Health program

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