21
May
Weed Killers Dicamba and 2,4-D Found in Pregnant Women in Midwest USA, Linked to Serious Effects
(Beyond Pesticides, May 21, 2024) In a first-of-its kind series of biomonitoring studies published in Agrochemicals, researchers identified the presence of the herbicides dicamba and 2,4-D in all pregnant participants from both cohorts in 2010-2012 and 2020-2022. The findings from this research are not surprising given the explosion of toxic petrochemical pesticides in the Midwest region of the United States. “The overall level of dicamba use (kilograms applied in one hundred thousands) in the U.S. has increased for soybeans since 2015 and slightly increased for cotton and corn,†the authors report, based on U.S. Department of Agriculture National Agriculture Statistics Service surveys. “The overall level of 2,4-D use (kilograms applied in one hundred thousands) in the U.S. was highest in 2010 for wheat, soybeans, and corn. The amount of 2,4-D applied increased the most for soybeans and corn from 2010 to 2020.†The researchers focused on the states of Illinois, Indiana, and Ohio, given the increase in dicamba and 2,4-D during the study period for both cohorts (2010-2022).
The researchers are based at Indiana University School of Medicine in the Department of Biostatistics and Health Data Science and Department of Obstetrics and Gynecology, Quebec Toxicology Center within the Institut national de santé publique du Québec, and Benbrook Consulting Services. Charles Benbrook, PhD one of the authors, served as an expert witness in herbicide litigation but stepped down as executive director of the Heartland Health Research Alliance to avoid any conflicts of interest pertaining to the studies cited in this report. The study was published online on February 20, 2024. The methodology included the analysis of urine samples from 2010-2012 Nulliparous Pregnancy Outcomes Study that enrolled 10,0037 pregnant participants from eight study sites across the three states, as well as a “smaller nested case-control study†in which 61 samples were gathered from women enrolled in the original study, in the first trimester in 2020-2022 periods, and based specifically in Indiana. “Cases were selected as participants in which any of the following occurred: hypertensive disorders of pregnancy, spontaneous preterm birth, gestational diabetes, stillbirth, or fetal demise < 20 weeks,†according to the researchers. The study identified metabolites found within the samples evaluated, “including herbicides (dicamba, 2,4-D, and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)), organophosphates insecticides (malathion dicarboxylic acid (MDA), para-nitrophenol (PNP), 3,5,6-trichloro-2-pyridinol (TCPy), 2-diethylamino-6-methylpyrimidin-4-ol (DEAMPY), and 2-isopropyl-6-methyl-4-pyrimidinol (IMPY)), and synthetic pyrethroids insecticides (cis-3-(2,2-Dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DCCA), trans-3-(2,2-Dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (trans-DCCA), 3-Phenoxybenzoic acid (3-PBA), 4-Fluoro-3-phenoxybenzoic acid (4-F-3-PBA), and cis-3-(2,2-Dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DBCA)).â€
“We found that dicamba in pregnant study participants increased significantly in the more recent Midwest cohort from 2020 to 2022 relative to the earlier cohort from 2010 to 2012,†the researchers arrive at this conclusion based on existing and recent studies. “Concentration levels of 2,4-D also increased in the more recent cohort, but the difference was not statistically significant.â€
There are a plethora of studies that demonstrate the adverse health effects of both dicamba and 2,4-D, even at low levels. The research reported in Agrochemicals adds to the knowledge of widespread exposure and adverse effects. For example, a 2021 study published in Toxicology found individuals working or residing in areas with frequent pesticide use, including 2,4-D, experience more incidences of neurodegenerative disease amyotrophic lateral sclerosis (ALS) relative to the general population. Additionally, studies published earlier this year in Toxics and Environmental Sciences Europe found increased instances of cancer, including liver cancer, as well as endocrine disruption and metabolic disorders via inducement of oxidative stress from chronic exposure to 2,4-D. A troubling trend found in a separate study published in Global Pediatric Health found that young people are facing an unprecedented rise in liver disorders and metabolic syndrome. Tracking the latest science, particularly regarding pesticide exposure and chemical mixtures, can help bridge the existing research gaps.
Regarding dicamba, exposure to the toxic herbicide has been linked to various cancers according to a 2020 research study published by the National Institute of Health in International Journal of Epidemiology. Dicamba has also been linked to neurotoxicity, birth defects, and kidney and liver damage, not to mention posing harm to birds, fish, and other aquatic organisms, according to various peer-reviewed studies identified in the Gateway on Pesticide Hazards and Safe Pest Management. Dicamba also causes serious damage to non-GE (genetically engineered), non-target plants, damaging habitat and food sources for various organisms, especially for birds, according to fieldwork by Audubon of Arkansas. See Daily News sections on dicamba and 2-4,D to learn more about the latest regulatory decisions and scientific literature pertaining to these two toxic pesticides.
There has been a flurry of litigation, industry reaction, and corresponding actions by the U.S. Environmental Protection Agency on dicamba since dicamba-tolerant soybeans and corn entered the domestic market back in 2016 when EPA initially registered dicamba-based products such as Xtendimax™. In 2020, the Ninth Circuit nullified “EPA’s 2018 conditional registration of three dicamba weed killer products for use on an estimated 60 million acres of DT (dicamba-tolerant through GE) soybeans and cotton,†finding that EPA did not adequately consider adverse health effects from over-the-top (OTT) spraying of dicamba in approving its conditional registration. Again, earlier this year in February, the U.S. District Court for Arizona rendered moot the EPA’s 2021 approval of three dicamba-based herbicides after a damning Inspector General Report called out EPA’s violation to both the Endangered Species Act and Federal Insecticide, Fungicide, and Rodenticide Act and the agency’s failure to appropriately manage resistance and the devasting impact this failure has on farmers’ livelihoods.
For context, according to USDA data gathered in 2018 and analyzed by Center for Food Safety, “As much as 1 in every 6 acres of ultra-sensitive soybeans were injured by dicamba drift in 2018 alone, over 15 million acres.†In spite of these developments, EPA announced an existing stocks order permitting use of dicamba products for the 2024 growing season just a few weeks after this most recent court ruling. The latest action regarding dicamba is the proposed registration of a new dicamba-based product for genetically engineered cotton and soybean crops with a 60-day public comment period that ends on June 3, 2024.
Advocates who champion public health, environmental protections, and organic agriculture and land management practices put faith in the decades-long body of scientific literature that demonstrates the adverse health effects of toxic chemicals, substances, and chemicals. In this context, EPA continues to permit the use of toxic pesticides, despite the compounding scientific research that supports Beyond Pesticides’s goal to eliminate toxic petrochemical-based pesticides by 2032, and replace the current system defined by product swapping with one that aligns with the National Organic Program and its National List of Allowed and Prohibited Substances.
See Keeping Organic Strong to engage with strengthening organic standards and opportunities to improve federal and state policies in support of organic agriculture and land management. See Tools for Change and Parks for a Sustainable Future to learn how to engage in eliminating toxic pesticides in your community. See Eating With a Conscience to learn which toxic pesticide residues are likely to show up in common produce items to better inform your next grocery haul.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Agrochemicals
