Link Found Between Pesticides and ADHD in Children

Wednesday June 02, 2010

It comes at no surprise that the ubiquitous use of pesticides is not only harmful to the environment, but especially harmful to humanity's future:  its children.

For years, science has known pesticides (containing organophosphates, also known as "Nerve Gas Relatives" per Radcliffe's IPM World Textbook) have been associated with adverse effects on neurodevelopment such as behavioral problems and lower cognitive function.  As such, there is a very good reason workers applying pesticides often wear rubber boots and gloves, protective eyewear, suits, and masks; they are protecting their health!

However, previously known scientific findings were based on studies of populations with high levels of exposure such as farm workers, residents of neighborhoods adjacent to industrial farms, and others with fairly regular contact with pesticides such as landscapers.

The recent study, conducted by researches at the University of Montreal and Harvard, narrows its aim and focuses on low-exposure children, ranging in age from 8-15, with established cases of attention-deficit/hyperactivity disorder (ADHD) and levels of organophosphate exposure common among US children.

Conclusions from the study support the hypothesis that levels common to US children of pesticides exposure "may contribute to ADHD prevalence" (Pediatrics 2010, 125:e1270-e1277).

The study notes, "approximately 40 organophosphate pesticides are registered with the US EPA for use in the United States.   In 2001, 73 million pounds of organophosphates were used in both agricultural and residential settings.  The EPA considers food, drinking water, and residential pesticide use important sources of exposure."  The study goes on to mention that "residential pesticide use is common, but the major source of exposure to pesticides for infants and children would be the diet, according to the National Academy of Sciences."  Interestingly, the ability of pesticides to linger in the environment long enough to travel onto our plate seems to contradict the scientific findings that organophosphates "are chemically unstable and nonpersistent" (Radcliffe's IPM World Textbook).

Although the study maintains the majority of exposure of pesticides is through diet (sounding a blaring case for organic food production), they do acknowledge that residential pesticide use is a common source for contamination.

This hoists a huge red flag for all landscapers, gardeners, and the general public alike.  Pesticides, whose long-range effects on human beings and the environment are just now being understood, should be treated with utmost skepticism and used (if ever) in the most cautious manner possible.  But unfortunately, the use of pesticides in the residential arena is often the most lax and misunderstood with homeowners and DIY’s who throw caution (and pesticide) into the wind by disregarding warning and instruction labels.  This inadvertently leads to improper use and allows chemicals to pollute our soil, air, water, and our health.

As landscape professionals who often work in the residential setting, the results of this study should ring clear.  Rather than responding defensively to this information, we should be angered that one of our common “tools” has such potential to negatively affect our children and environment.  In response, we should be inspired to pledge to implement even stricter guidelines for pesticide use – starting with our own practice.  Additionally, we should embrace the notion of Integrated Pest Management and begin to address landscape challenges more holistically.  For example, install mulch to keep weeds at bay as opposed to spraying pesticides.  Spraying may temporarily address the symptoms but laying mulch will solve the problem.

One of our most integral responsibilities as landscape designers, contractors, and maintenance workers is to design, build and maintain safe and sustainable environments to be enjoyed by all.  To this successfully, we must begin to question or reliance on pesticide use and carefully analyze its role in construction and maintenance programs. 

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