“Although people argue against costly regulations, unrestricted use of these chemicals is far more expensive in the long run, with American children bearing the largest burden.”

(Beyond Pesticides) Exposure to environmental chemicals in the U.S. since the turn of the century has resulted in millions of lost IQ points, hundreds of thousands of cases of intellectual disability, and trillions of dollars of lost economic activity. This is according to a study led by a team of scientists at the New York University Grossman School of Medicine, published in the journal Molecular and Cellular Endocrinology. “Although people argue against costly regulations, unrestricted use of these chemicals is far more expensive in the long run, with American children bearing the largest burden,” says senior study author Leonardo Trasande, MD, MPP in a press release.

Exposure to environmental chemicals can result in neurotoxic effects. Prenatal exposure represents a critical window when these effects can be particularly pronounced and result in lasting damage to a child. Researchers focused their study on contact with mercury, lead, organophosphate pesticides, and flame retardants in the womb.

Biomonitoring data from a long-running Centers for Disease Control and Prevention study on environmental chemicals was used to determine exposure levels. Because each chemical results in differing levels of intellectual damage, each was assigned an IQ impact based on past research. For example, scientists indicated that 4.25 IQ points are lost for every 10-fold increase in organophosphate exposure. Intellectual disability was determined to be when IQ dropped below 70. Again using previous research, each lost IQ point was assigned a value of $22,268. Each case of intellectual disability was estimated to result in $1,272,470 in lost productivity. These dollar amounts are all inflation-adjusted to the year 2018.

With increased attention to childhood lead and mercury exposure, the contribution of these chemicals to IQ decay remains significant yet declined over the last two decades. At the same time, the proportion of IQ loss attributable to flame retardants (polybrominated diphenyl ethers [PBDEs]) and organophosphate pesticides has increased substantially, from 67% to 81%. Flame retardants were identified as the most costly contributor, resulting in over 162 million lost IQ points and 738,000 cases of intellectual disability, totaling over $4.5 trillion over the course of the entire study period (2001-2016). Although exposure from lead declined over the study period alongside IQ loss, there is no safe level of exposure to the metal for children, resulting in neurotoxic effects. Lead-attributable IQ loss declined from 8 million per year in 2001 to 2 million in 2016.

Despite modest declines in organophosphate pesticide use over the study period, the impacts of organophosate exposure appear roughly on par with lead exposure. Pesticides were estimated to result in over 26 million lost IQ points and over 110,000 cases of intellectual disability, totaling roughly $735 billion in economic costs. The total impact of all the chemicals studied by researchers is estimated at nearly 200 million lost IQ points, and almost 1.2 million cases of intellectual disability, costing the U.S. economy an astounding $7.5 trillion.

Scientists attribute the continued effects of flame retardants and pesticides to lax regulation and unwillingness to adequately address exposure by government officials. The paper cites the failure of the Trump administration to ban chlorpyrifos as evidence that exposure to this highly toxic class of chemicals is likely to increase. “Unfortunately, the minimal policies in place to eliminate pesticides and flame retardants are clearly not enough,” said lead study author Abigail Gaylord, MPH.

The study also raised the prospect of regrettable substitutions, whereby chlorpyrifos would be replaced with another neurotoxic chemical class, such as the synthetic pyrethroids, as a reason for overhauling the way the nation analyzes hazardous pesticides. “Without proper toxicological testing standards for industrial chemicals in the United States we run the risk of introducing chemicals that are just as bad, or even worse, for human health,” the study reads.

Lead exposure is on the decline due to its removal in gas and paint, but legacy exposure in paint and pipes continues to plague communities like Flint, Michigan. Mercury exposure has been reduced due in part to regulations on coal plant emissions, but remains a significant risk for certain regions of the country. Flame retardants can in some instances be avoided through careful purchases on items like furniture but necessitate increased regulation. Likewise, individuals can focus on eating organic food in order to reduce organophosphate exposure, but uses remain on golf courses and for mosquito control, and farmworkers and agricultural communities are disproportionately impacted.

See here and here for past coverage of NYU’s work to uncover the hidden costs of environmental chemicals on our children’s intelligence and our economy. For more evidence on the need for increased regulation and the organic solution, see Beyond Pesticides’ Pesticide Induced Diseases Database and the Why Organic program page.

All unattributed positions and opinions in this piece are those of Beyond Pesticides.