Pesticide Runoff Can Pose Risk to Humans, Wildlife in Chesapeake Bay Region

Pesticides used by farmers, residents and business owners pose a significant risk to Chesapeake Bay wildlife and human health, according to a recent report released by the Maryland Pesticide Network.

Pesticides and the Maryland Chesapeake Bay Watershed lists the major types and sources of pesticides in the Bay region and explains how pesticides can affect the fish we eat and the water we drink. Toxic chemicals in pesticides can move up the food web when larger fish and birds eat smaller, contaminated organisms. Humans can also be affected if they catch contaminated fish or drink contaminated water.

According to the report, pesticides are a threat to the region’s environmental health because they can be toxic to aquatic life, wildlife and humans, even though those species are not being targeted by the pesticide applier. Even at low levels, toxic effects of pesticides can put additional stress on fish, plants, microscopic animals and other species. A 2007 report by the U.S. Geological Survey found that synthetic organic pesticides were widely detected at low levels throughout the Bay watershed.

One type of pesticide discussed in Pesticides and the Maryland Chesapeake Bay Watershed is atrazine, the most commonly used herbicide in the United States. Atrazine, which is used in both agriculture and on lawns, has been linked to sexual abnormalities in frogs and is a suspected endocrine disruptor: a substance that mimics hormones and can cause reproductive anomalies.

Pesticides get into our local waterways and the Chesapeake Bay when we apply them to the ground and rain washes them into nearby streams and storm drains. The largest source of pesticides in the Bay watershed is from agriculture, but commercial, residential and government properties also contribute measurable amounts of pesticides to local waterways and groundwater supplies. Pesticides used in our homes, such as the antimicrobial ingredient triclosan in soaps and personal care products, can also find their way into the Bay through treated wastewater.

Fortunately, there are many ways people can help reduce the flow of pesticides to the Chesapeake Bay and its rivers, from using effective pesticide alternatives to taking preventative measures rather than resorting to pesticides. The report’s conclusion outlines several recommendations for consumers, regulators and policymakers, including:

• Educating residents about mosquito breeding habits to reduce the need for spraying.
• Planting forest buffers along the edges of farm field to reduce polluted runoff into local waterways.
• Promoting the use of Integrated Pest Management (IPM), a strategy that uses mostly non-chemical prevention techniques on farms and in residential gardens.
• Supporting research on the effects of pesticides – from endocrine-disrupting chemicals to the interaction of multiple pesticides in the water – on wildlife, aquatic life and human health.

For more information, read the full Pesticides and the Maryland Chesapeake Bay Watershed report.