The Maryland General Assembly should ban the toxic pesticide chlorpyrifos when they return to work in January. They had the chance to put the ban in place this year, but many legislators wrongly believed that the Environmental Protection Agency would follow the science and ban the chemical as the agency had proposed in 2016. As a result, the state bill to ban chlorpyrifos failed to pass.

However, in mid-July the EPA declined to ban chlorpyrifos, despite its own experts linking its use to serious health problems in children. The agency argued that the pesticide is needed to protect crops.

Given the EPA’s inaction, we urge Maryland leaders to ban it. One of us is a public health professor at the University of Maryland, the other a senior scientist with the Chesapeake Bay Foundation. We know the risks to our children and the bay are significant if this pesticide continues to be applied.

Chlorpyrifos is a powerful neurodevelopment toxicant. It is most commonly used in agriculture to kill insects on crops or to treat seeds before they’re planted.

In 2016, an EPA scientific panel advised the agency that small amounts of chlorpyrifos exposure can harm infants while in the womb and early in their lives. This exposure can impair children’s ability to recall information necessary for learning and result in reduced academic achievement in their later years. Already the EPA has detected levels of chlorpyrifos in food that is 140 times higher than EPA deems safe for children ages 1 to 2, and 62 times above acceptable levels for women of reproductive age. The agency also warned there is no safe level of the pesticide in drinking water.

After the pesticide is applied on farm fields or elsewhere, it can be washed into streams, rivers, and the Chesapeake Bay when it rains. Since the early 1990s, scientific studies have found trace amounts of chlorpyrifos can harm the central nervous systems of crustaceans such as crabs and shrimp. It can also kill insect larvae — an important food source for marine life in the bay. The ongoing use of the pesticide has the potential to harm Maryland’s iconic blue crab fishery as well as the myriad insects and smaller crustaceans that support the base of the bay’s marine food web.

We understand that some farmers said the pesticide is only needed to treat seeds, while other supporters of the pesticide argued it’s needed to stop the invasive spotted lanternfly from spreading in the region. However, there are alternatives. At the Chesapeake Bay Foundation’s Clagett Farm in Upper Marlboro, we successfully grow plants such as sweet corn, kale, collards, cabbage and strawberries without chlorpyrifos. As for lanternfly control, Penn State University recommends several natural methods to control the spread of the pest as well as chemicals other than chlorpyrifos.

Chlorpyrifos is already being slowly phased out in Maryland, according to usage estimates from the Maryland Department of Agriculture. In 2004, the department estimated about 238,000 pounds of chlorpyrifos was applied in the state. By 2014, the most recent year the department has released publicly available statistics on pesticide usage, about 3,900 pounds of the pesticide was applied. The decreasing use shows that an outright ban won’t have a major impact on the state’s agriculture industry.

It’s obvious that the state can’t depend on the EPA to protect Maryland’s children and the Chesapeake Bay from the harmful effects of chlorpyrifos. It’s time for the state Legislature to do so.

Devon Payne-Sturges is an assistant professor at the Maryland Institute for Applied Environmental Health.

Doug Myers serves as the Maryland senior scientist for the Chesapeake Bay Foundation.

(2) comments


Agreed. There are demonstrated long-term detrimental effects on the environment due to this pesticide. A recent article in this space pointed to an interesting anecdotal observation that there are less flying insects recently. We rely on these insects to pollinate our fruit trees, and many other plants. What will we do when they're gone?


Spot on and a correct move to make. Thank you for this.

Welcome to the discussion.

Keep it clean. Please avoid obscene, vulgar, lewd, racist or sexually-oriented language.
Engage ideas. This forum is for the exchange of ideas, insights and experiences, not personal attacks. Ad hominen criticisms are not allowed. Focus on ideas instead.
Don't threaten. Threats of harming another person will not be tolerated.
Be truthful. Don't knowingly lie about anyone or anything.
Be nice. No racism, sexism or any sort of -ism that is degrading to another person.
No trolls. Off-topic comments and comments that bait others are not allowed.
No spamming. This is not the place to sell miracle cures.
Say it once. No repeat or repetitive posts, please.
Help us. Use the 'Report' link on each comment to let us know of abusive posts.