Flaws in Key American Academy of Pediatrics (AAP) Report Calls into Question Local Government Initiatives on Pesticide Exposure

Contact:  John Heinze, PhD

Flaws in Key American Academy of Pediatrics (AAP) Report
Calls into Question Local Government Initiatives on Pesticide Exposure

CHANTILLY, Va., July 10, 2015— A Scientific Evaluation issued by the Environmental Health Research Foundation (EHRF) has revealed serious omissions and mischaracterizations in both a December, 2012 Policy Statement by the American Academy of Pediatrics (AAP) on Pesticide Exposure in Children and a corresponding Technical Report[1] by the AAP’s Council on Environmental Health which provides key support for the Policy Statement. EHRF’s Scientific Evaluation was initiated in response to a proposed County ordinance in Montgomery County, Maryland[2] which referenced the AAP report as part of the rationale for advancing the proposed ordinance. Given the EHRF’s longstanding interest in examining the extent to which public policy is based on sound science, EHRF undertook a review of the scientific basis of the AAP Policy Statement and Technical Report.

The EHRF evaluation assesses both the quality of the scientific support for the AAP Policy Statement based on its reliance upon the Technical Report and the Policy Statement’s blanket conclusion which suggests that commonly-used pesticides registered by the US Environmental Protection Agency (US EPA) present the same chronic health effects as those pesticides reviewed in the Technical Report.  The evaluation was conducted by John Heinze, Ph.D., Executive Director of the Environmental Health Research Foundation (EHRF), and is part of a larger, multi-year review of green space-related issues undertaken by the EHRF that includes a variety of other studies which evaluate potential adverse health effects which may result from pesticide exposures.

In the evaluation, Heinze noted that “The American Academy of Pediatrics Policy Statement rightly attempts to offer guidance on an important topic – namely, children’s health and the potential chronic health impacts for children arising out of exposures to pesticides.  Unfortunately, in our view, there are serious weaknesses in the Technical Report and we believe that the Policy Statement’s conclusion that ‘pesticides cause chronic effects,’ overstates the more cautiously worded conclusion of the Technical Report which stated “there is a growing body of literature that suggests that pesticides may induce chronic health complications in children, including neurodevelopmental or behavioral problems, birth defects, asthma and cancer.”  By omitting important qualifying words such as ‘suggests’ and ‘may’, the Policy Statement overstates the conclusion of the Technical Report and could cause non-technical readers to misinterpret its meaning.”

Heinze also noted that the AAP Technical Report appears to ignore the considerable data that has been generated through the US EPA product registration process.  This long-standing EPA process rests upon a science-based decision making methodology that requires a demonstration that “the pesticide, when used according to label directions, can be used with a reasonable certainty of no harm to human health and without posing unreasonable risks to the environment.[3]

Importantly, Heinze stated that in determining a pesticide’s potential risk, US EPA employs a rigorous set of criteria that includes hazard identification, dose-response assessment and exposure assessment to create an overall risk characterization.  He compared the EPA’s detailed and well-established risk assessment process to the Technical Report’s lack of meaningful risk characterization.

Heinze observed that the Technical Report and the Policy Statement incorrectly imply that mere exposure to a “hazardous” pesticide is equivalent to risk.  He stressed that “risk is determined by comparing exposure level to a safety level, typically a level set by a health agency”.  As an example, he said that the “exposure levels for three currently used pesticides (2,4-D, deltamethrin, and cyfluthrin) from biomonitoring studies were compared to biomonitoring equivalent safety levels.  Exposure levels were found to be hundreds of times lower than safety levels, indicating low risk.”

In addition, Heinze stated that both the AAP Policy Statement and the related Technical Report could create the impression among non-technical readers that several commonly-used and widely-available pesticide products present the same level of risk as the known “bad actor” products that the Technical Report reviews.  As an example, Heinze observed that “there is a significant difference between a banned product like 2,4,5-T and a registered product like 2,4-D in terms of the risk presented.”

The EHRF study of the AAP Policy Statement and the corresponding Technical Report details a number of areas of concern regarding the utility of both documents.  For example, non-technical readers could fail to understand that more than two-thirds of the “highly toxic” pesticides listed in the AAP’s Technical Report have either been banned for more than a quarter century or are no longer approved for residential use.  Specifically:

  •  The AAP Technical Report identifies 14 “highly toxic” pesticides but does not provide a full or accurate description of their use pattern.  Of these 14:
    •  Five have been banned for over 25 years (DDT, enduring, aldrin, chlordane and parathion)
    •  Five are no longer approved for residential use (acephate, chlorpyrifos, methyl parathion, aldicarb, and paraquat)
    •  One has limited residential use (diquat)
    •  One is approved only for medical use (lindane) and
    •  For another, human exposure is unlikely (dichlorvos).

Based on these use patterns, human exposure is likely to be very low. Indeed, the fact that 72% of the identified products have either been banned for 25 years or are no longer approved for residential use indicates the potential for confusion, especially among non-technical readers, as to understanding issues involved in potential exposure to products approved for use around the house, or on public playgrounds and parks.

  • As for the remaining pesticide (carbaryl), it is registered for both agricultural as well as residential use by the US EPA.
    •   This means that the EPA’s rigorous testing of the products has determined that there are appropriate uses for the product consistent with the Agency’s charge of assuring that there is a “reasonable certainty (of) no harm” to people, animals or the environment from the product (if applied according to label instructions).[4]
    •   The classification in the Technical Report that this product is “highly toxic” is undefined in the Report and inconsistent with both fundamental principles of toxicology which prescribe that toxicity cannot be defined without stating the dose and route of exposure and with EPA definitions of these terms.
    •   For carbaryl, toxicity via dermal or inhalation routes of exposure, the most likely routes of accidental exposure, is considered to be low while toxicity via oral exposure is considered to be moderate.  There is no route of exposure to which EPA considers carbaryl to have “high” toxicity.[5]
  • The Technical Report mischaracterizes 2,4,5-T as a “commonly used herbicide” when, in fact, it was banned in the US nearly three decades ago in 1985.  The Report also characterizes 2,4-D as a hazardous substance (“moderately toxic” in Technical Report Table 1), apparently because “toxic substances can be produced during its manufacture including dioxins.” However, the Report doesn’t offer any documentation that would contradict EPA’s current assessment that “2,4-D uses (tolerances) are safe.”[6]
  • The Technical Report incorrectly implies that mere exposure to a “hazardous” pesticide is equivalent to risk.  Risk is determined by comparing exposure level to a safety level, typically a level set by a health agency.  As an example, exposure levels for three currently used pesticides (2,4-D, deltamethrin, and cyfluthrin) from biomonitoring studies were compared to biomonitoring equivalent safety levels.  Exposure levels were found to be hundreds of times lower than safety levels, indicating low risk.
  • The Technical Report cites the Centers for Disease Control National Biomonitoring program data as a source for biomonitoring information on pesticide exposures but overstates the number of pesticides detectible in the CDC biomonitoring program, claiming that 29 of 44 (66%) were detectable when, in fact only 22 of 51 (43%) were detectable.
  • The Technical Report’s claims of chronic health effects resulting from pesticide exposure (i.e., childhood cancer, neurodevelopmental effects, physical developmental defects, endocrine effects, asthma) are based on human epidemiology studies which have a number of scientific limitations, including: an inability to demonstrate critical causal relationships (i.e., correlation is not causation), insufficient information on dose response and a lack of supporting information regarding causes of developmental defects, endocrine effects, and asthma.

The EHRF concludes by stating that the available science does not support the concerns expressed in the Policy Statement regarding pesticides and chronic health effects.  The Technical Report, which serves, in part, as a basis for the Policy Statement, contains important omissions and mischaracterizations which limit the Policy Statement’s utility and calls into question the Report’s validity and the recommendations set forth by the Policy Statement.

To see all of EHRF’s work on greenspace-related issues, go to www.ehrf.info

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About EHRF

The Environmental Health Research Foundation (EHRF) is a nonprofit, nonpartisan scientific research foundation seeking to improve the analysis and communication of health and environmental science. Its goal is to further the understanding of science related to health and the environment, and especially the interaction between the environment and human health. EHRF Executive Director John Heinze, PhD brings over 20 years of research, management, and communications experience to the EHRF. In addition to his expertise in microbiology, molecular biology, genetics, and toxicology, Heinze has authored over 35 scientific papers and presentations to international conferences and workshops. Since 1995, Heinze has served as a senior science adviser on health and environmental issues, including the communications aspects of such issues. A particular focus has been on communication of health and environmental safety information including activities ranging from those focused on single substances to broad issues affecting numerous materials.

[1] Roberts JR, Karr, CK; American Academy of Pediatrics, Council on Environmental Health.  Technical report – pesticide exposure in children.  Pediatrics. 2012:130(6)

[2] Other local jurisdictions have considered similar ordinances, often referencing the AAP Policy Statement and Technical Report, or similar justification.

[3] U.S. Environmental Protection Agency. Pesticides. Regulating Pesticides.  Last updated 29 May 2014.  Available at: www.epa.gov/pesticides/regulating/

[4] U.S. Environmental Protection Agency, “Carbaryl: Order Denying NRDC’s Petition to Revoke Tolerances.” 40 CFR Part 180, Docket: EPA-HQ-OPP-2008-0347; FRL-8388-1, available at: http://www.gpo.gov/fdsys/pkg/FR-2008-10-29/pdf/E8-25693.pdf

[5] National Pesticide Information Center,  Carbaryl (General Fact Sheet) Oregon State University, 2003, http://npic.orst.edu/factsheets/carbgen.pdf

[6] U.S. Environmental Protection Agency, EPA Denies Petition on 2,4-D Pesticide, 9 Apr. 2012. Web. 16 Oct. 2012. http://www.epa.gov/oppfead1/cb/csb_page/updates/2012/2-4d-petition.html.