At a Glance

Scientists found traces of neonicotinoids in samples of treated tap water in Iowa.The pesticide is linked to declining bee colonies and some bird populations.Researchers say the find is not a cause for alarm just yet.

Scientists have discovered traces of one of the world's most popular and controversial bee-killing insecticidesin Iowa's drinking water.

According to conducted by the United States Geological Survey and the University of Iowa and published Wednesday in Environmental Science and Technology Letters, researchers say insecticides known as neonicotinoids were found in samples of some treated tap water collected in Iowa. Other samples in the state that used a different method of filtration were found to have lesser amounts of the chemical.

According to the study, tap water from the samples with the higher concentration of the chemical had 0.24 to 57.3 nanograms of individual neonicotinoids per liter.

"These are very low levels," Gregory LeFevre, one of the authors of the study from the University of Iowa, . "But at the same time, there are concerns about what those low levels might do from an exposure standpoint."

While the health impact of the chemical on humans is unknown, scientists say further study is necessary.

Neonicotinoids are very popular but . So much so that The European Union banned the use of them on flowering crops in 2013. In the United States,the Environmental Protection Agency has not identifiedneonicsas a threat and there are no regulatory limits in place for these substances. Studies conducted have shown that over a brief period results in “low rates of adverse health effects” for humans.

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LeFevre told The Washington Post that .

“Having these types of compounds present in water does have the potential to be concerning,” he told the Post, “but we don’t really know, at this point, what these levels might be.”

The pesticides became popular in the 1990s and were meant to be more environmentally friendly. They work by paralyzing and eventually killing pests that wreak havoc on crops. However, the chemical became linked to declining bee colonies and has shown a ripple effect in the food chain. A 2014 study found that that hadless to eat.

Also in 2014, the USGSfound collected from nearly 50 different rivers and streams in the United States.

While the EPA reassures residents that there is no cause for alarm, George Washington University public health researcher Melissa Perry told the Washington Post the new study “provides further evidence that neonicotinoid pesticides are present in our daily environments. From a public health standpoint, this issue clearly needs better attention."

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