Mead residents still being exposed to pesticides from AltEn, study shows

A study of 21 people conducted jointly by the University of Nebraska and Creighton University found one-third of residents living near AltEn had measurable amounts of pesticides commonly used in seed treatments in their urine.

AltEn used discarded seeds coated with neonicotinoids to make ethanol — an unusual process among ethanol plants in the U.S. — which also created heavily contaminated solid and liquid byproducts.

Those waste products were spread on area farm ground or stockpiled on AltEn’s facility roughly 2 miles south of Mead where they were exposed to the elements.

The plant shut down in 2021 after the company came under scrutiny of environmental regulators and efforts to clean up the site began shortly after.

Of the seven area residents who showed detectable levels of insecticides in the university study, three had concentrations comparable to what was found in a 2015-16 study of the general population conducted by the National Center for Environmental Health, a division of the Centers for Disease Control.

That survey showed roughly half of all Americans had between 0.4 and 2.8 parts per billion of the insecticide imidacloprid in their bodies on average — an exposure the 2019 study said was likely through consuming foods treated with the compound.

The other four samples submitted by Mead residents in 2022 showed concentrations of imidacloprid well above the range recorded in the CDC study, according to Eleanor Rogan, an associate dean in UNMC's College of Public Health who is leading the research effort.

Those quantities ranged between 12 parts per billion to 42 parts per billion, a concentration roughly 20 times higher than the average reported in the CDC study.

A second round of testing done earlier this year once again showed roughly one-third of participants in the study had detectable amounts of neonicotinoids in their urine, Rogan added, though at lower levels than the first round of testing.

One sample in the second round of testing recorded imidacloprid at roughly 16 parts per billion, according to Rogan, while others were within the range of the CDC study.

The low numbers also fall under the benchmark the Environmental Protection Agency considers unsafe for human exposure, which is also the figure used by the Nebraska Department of Environment and Energy.

While the decline in concentrations is encouraging, and tracks with what researchers have seen in other facets of their wide-ranging study, Rogan said that the results demonstrate residents of Mead continue to be exposed to chemicals from the AltEn plant.

"The neonics don't hang around," Rogan said, adding they dissolve quickly in water and are passed through the human body. "If we are still detecting them in people, they are still getting exposed."

The study was done more than 18 months after the plant stopped its operations, and months after the AltEn Facilty Response Group — six agribusiness giants who formerly supplied seed to AltEn — capped an estimated 84,000 tons of pesticide-contaminated solid waste under a layer of concrete and clay.

Those measures have helped control the spread of the waste through the environment, Rogan said, and point to contaminated dust already in the homes of Mead-area residents as the likely route of exposure for many.

Mead's source of drinking water is upgradient from the AltEn plant and not affected by any pesticide contamination, according to village officials.

Rogan said more research is needed, both among residents living in proximity to AltEn as well as on the effects of neonicotinoids on humans in general.

The university study is limited in its scope as well as its geography, Rogan said. Researchers would like to expand the study to people living south and east of AltEn, as well as attract more volunteers to provide blood and urine samples in order to determine their level of exposure.

The studies also record a snapshot in time and do not provide evidence linking exposure to chemicals at AltEn to any health conditions, she said.

In fact, Rogan said the science around the effects of neonicotinoids on humans is incomplete, though there is a scattering of studies linking exposure to conditions ranging from autism to respiratory illnesses, obesity and diabetes.

"Those are just associations, not cause and effect," she said. "It would take a long-term, big study to try and see what the health effects are."