FAIRFAX, Va. - Earlier this week Environmental Health Perspectives released an advance publication of a study from a group of researchers in California called "Neurodevelopmental Disorders and Prenatal Residential Proximity to Agricultural Pesticides: The CHARGE Study." The exploratory research examined whether residential proximity to agricultural pesticides during pregnancy is associated with autism spectrum disorders or developmental delay, and claims to have found evidence linking neurodevelopmental disorders with gestational pesticide exposures, and particularly, organophosphates.
Researchers reviewed the residential addresses of mothers of children enrolled in the Childhood Autism Risks from Genetics and Environment (CHARGE) Study during the time of their pregnancies and compared the information to commercial pesticide application data from the California Pesticide Use Report (1997-2008).
The CHARGE Study, an ongoing California population-based case-control study that examines environmental causes and risk factors for autism and developmental delay, launched in 2003 and is sponsored by the National Institutes of Health and the EPA. The group currently has about 1,600 enrolled families and the
children in the study are divided into three groups: children with autism, children with developmental delay, and children chosen at random from the general population.
Although the majority of participants, even those with autism and developmental delays, had not lived near any pesticide applications during their pregnancies, about one-third had been within a mile of where the products were applied.The study evaluated pesticide application data of organophosphates, organochlorines, pyrethroids and carbamates, and concluded that organophosphates were the most commonly applied agricultural pesticide near the homes of CHARGE Study mothers during the time of gestation. The study also examined specific windows of vulnerability during gestation, such as the second and third trimesters.
Experts have begun poking holes in the study, questioning the science as well as the conclusions, as referenced here in this HealthDay article published on WebMD:
"While the association between possible pesticide exposure and autism is interesting, an expert not involved in the research pointed out that it has a major flaw.
Because the study looked back in time, researchers weren't able to collect blood or urine samples to directly measure pesticide exposures. And they looked at risks associated with four different classes of chemicals.
'So this study cannot pinpoint specific substances as a culprit,' said Philippe Grandjean, an adjunct professor of environmental health at Harvard School of Public Health in Boston. 'Also, they cannot relate to specific levels of exposure, and they have not taken into account the possible contribution by residues in food,' he said.
As a result, he said, the link reported in this study is weak."
However, other media outlets covering the results of the study aren't doing as much research and are incorrectly bridging the gap between agricultural product applications and pesticide use in structural pest control. One of the lead researchers and authors of the study, Irva Hertz-Picciotto, an environmental epidemiologist at the MIND Institute at University of California, Davis, is advising expecting mothers to use less toxic alternatives, like diatomaceous earth, to curb insect problems in the home. Others are using the results of the study to encourage pregnant women and those considering pregnancy to avoid the use of pesticides in and around the home completely.
NPMA has reviewed the recent study published in Environmental Health Perspectives and believes that the methodology and assumptions of the study are flawed and therefore the conclusions are inaccurate and misleading; in fact, such poorly conducted research presented as fact may divert attention away from the real research that is needed to understand more about causes of autism and developmental delays. It's also important to note that this study evaluated a regional sample (parts of California) to determine whether residential proximity to agricultural pesticides during pregnancy is associated with neurodevelopmental disorders among participants in the Childhood Autism Risks from Genetics and Environment (CHARGE) Study and that approximately two-thirds of respondents reported no residential proximity to agricultural pesticides during the time of their pregnancies. No other factors were evaluated.
Within the professional pest management industry, products used to address pest infestations - infestations, which can negatively affect public health and property - are an important and essential tool. All pest products used by the industry are reviewed and registered by the Environmental Protection Agency (EPA) and as such, consumers should feel confident that the application of these products will be done expertly by qualified pest professionals, as directed on the product label.
Crop Life America Statement
NPMA's colleagues at CropLife America, a crop protection association that represents the companies that develop, manufacture, formulate and distribute crop protection chemicals and plant science solutions for agriculture and pest management, issued this statement and guidance on the poor methodology of the study.
• All products used in the treatment of structural pest infestations - for which NPMA members are responsible - are rigorously studied, reviewed and registered by the Environmental Protection Agency (EPA) to be used by certified applicators for pest management. The NPMA works closely with the EPA to ensure that all products used in pest management practices are consistently reviewed, re-evaluated, re-registered and provided with accurate and comprehensive labeling for use.
• The study draws particular attention to organophosphates, a class of insecticides that is not commonly used in structural pest control; however, they are used in agriculture applications and in mosquito abatement programs, etc. Organochlorines are also not used in structural pest control.
• It is important to remember, leaving pests unmanaged can lead to real health and structural issues. If concerned by the issues raised in the study covered in the Environmental Health Perspectives journal as related to your overall pest management plan, the NPMA encourages consumers to consult with a qualified and licensed pest professional to discuss these concerns and discuss the proactive and preventative measures that they can take to avoid pest infestations. More importantly, by working with a pest professional, consumers can ensure that a pest problem is properly identified and effectively treated.
WebMD via HealthDay: Pesticide Exposure in Pregnancy Tied to Autism Risk: But it doesn't prove pesticides cause autism and didn't directly measure women's chemical exposure, expert notes. By Brenda Goodman.
Neurodevelopmental Disorders and Prenatal Residential Proximity to Agricultural Pesticides: The CHARGE Study. By Janie F. Shelton, Estella M. Geraghty, Daniel J. Tancredi, Lora D. Delwiche, Rebecca J. Schmidt, Beate Ritz, Robin L. Hansen, and Irva Hertz-Picciotto. June 2014.
The CHARGE study, UC Davis M.I.N.D. Institute.