We need more information about pesticides

Every day, Marylanders are exposed to pesticides in our drinking water, on our food and through chemicals in our homes, lawns and public spaces. We also encounter pesticides in our rivers and streams and the Chesapeake Bay. While these exposures are often in small doses, growing evidence suggests they can add up to great harm. Unfortunately, the very public health officials responsible for protecting us are denied basic information about when and where dangerous pesticides are used.

In Maryland, it is almost impossible for health care providers, public health experts and biomedical researchers to accurately understand the risks pesticides pose. We cannot easily determine whether a fish kill in the Chesapeake Bay is the result of a recent herbicide spraying or if an autism cluster can be connected to pesticides used locally.


It's time to change that with passage of the Pesticide Information Act slated to go before the Maryland General Assembly in 2013. The bill requires pesticide applicators, as well as sellers of restricted use pesticides, to report information they are required to collect anyway on pesticide use and sales.

Not surprisingly, pesticides pose the greatest risk to the smallest among us: infants and children. Pesticide exposure during pregnancy and childhood is now linked to certain childhood cancers and other health conditions, including impaired cognitive function and behavioral problems. Just a few weeks ago, in response to growing scientific evidence, the American Academy of Pediatrics — more than 60,000 professionals devoted to the health and safety of American's children — took an important step by issuing its first policy statement aimed at minimizing pesticide exposure in children.

As physicians who represent the Maryland Chapter of the Academy of Pediatrics and Baltimore Physicians for Social Responsibility, respectively, we feel a growing alarm about the mounting evidence linking pesticides to a number of acute and long-term health problems. Exposures to pesticides are linked to many chronic illnesses, including asthma, autism spectrum disorders, attention deficit hyperactivity disorder (ADHD), cancer and Parkinson's disease, as well as to birth defects and fertility problems.

Until very recently, the paradigm "the dose makes the poison" guided the field of toxicology. This principle — which influenced much scientific study and regulatory law — is being turned on its head by new data and new ways of measuring toxins in water, food and our bodies. New research, noted in a 2012 article by the National Institute of Environmental Health Sciences, shows that long-term, minutely low-level exposure to certain pesticides may be just as harmful as high levels of intermittent exposure and may affect greater numbers of people.

And emerging proof shows that low-dose impacts of a particular kind of hormone-mimicking chemical called endocrine-disrupters, which includes many pesticides, can adversely affect both humans and aquatic species. While our focus is clearly on human health, we recognize that signals of health problems in other species may provide clues about diseases in humans. For example, growing data show links between atrazine, a commonly used herbicide, and intersex fish showing both male and female characteristics, suggesting an effect on reproductive systems.

It's clear that we must improve our information about these chemicals so we can continue to understand the health risks from exposures and better protect our children and ourselves.

Maryland has reinstituted a voluntary survey of pesticide applicators' usage, to be published in a hard copy report once every five years beginning in 2013. This is an outdated format and is inadequate.The last published voluntary survey, in 2004, had low reporting rates (participation was only about 55 percent) and provided skewed, inaccurate data.

Since that same year, Maryland has required health care providers to report suspected pesticide exposure. However, investigating such exposures in a timely and accurate manner becomes challenging, if not impossible, without basic pesticide information.

As physicians, we need all the tools at hand to help us better understand the risk that pesticides pose to human health and to protect our children. We believe that the implementation of a mandatory pesticide reporting database, through the 2013 Pesticide Information Act, would be an essential tool to help us provide the best care possible for Maryland families.

Dr. Lorne Garrettson ( is a professor emeritus of pediatrics at Emory University. Dr. Richard L. Humphrey ( is an associate professor of pathology at Johns Hopkins School of Medicine.