Health and Medicine
PUBLISHED
7
One in three Americans has traces of weed killer 2,4-Dichlorophenoxyacetic acid (2,4-D) in their body, according to a study published in the journal Environmental Health.
Scientists at George Washington University in DC studied 14,395 people in the US, finding that nearly 33 percent had detectable levels of a 2,4-D biomarker in their pee. The situation also appears to be getting worse – the number of participants with high 2,4-D levels rose significantly from 17 percent in 2001–2002 to 39 percent in 2011–2012.
"Our study suggests human exposures to 2,4-D have gone up significantly and they are predicted to rise even more in the future," Marlaina Freisthler, a PhD student and researcher at George Washington University, said in a statement.
"These findings raise concerns with regard to whether this heavily used weed-killer might cause health problems, especially for young children who are very sensitive to chemical exposures."
2,4-D kills broadleaf weeds by sparking uncontrolled cell growth, but leaves other plants largely unscathed. The chemical was a key ingredient of Agent Orange, the infamous herbicide used to strip the forest of leaves in the Vietnam War.
The prolific use of this chemical during the war caused major health problems for many people who were exposed, plus their offspring. However, the majority of participants in this study likely came across the chemical because it is one of the most widely available weed killers in the world.
Kids can pick up the chemical just by playing on a lawn treated with it. Food and agriculture are other common routes of exposure since 2,4-D is widely used on GMO soybeans and cotton, causing the herbicide to enter the air and surrounding environment.
The impact of the chemical on human health is not widely agreed on by health authorities. However, it has been linked to a number of health concerns – especially for children, women of childbearing age, and highly exposed individuals such as farmers.
The US Environmental Protection Agency says 2,4-D “generally has low toxicity for humans, except certain acid and salt forms can cause eye irritation.” On the other hand, a World Health Organization study in 2015 concluded that the herbicide can “possibly” cause cancer. Given this potential risk, the Natural Resources Defense Council has called 2,4-D "the most dangerous pesticide you've never heard of.”
Although the impact on health is hazy, the researchers say their latest discovery highlights the need to get a better understanding of what 2,4-D is doing to our bodies.
“Further study must determine how rising exposure to 2,4-D affects human health – especially when exposure occurs early in life," explained Melissa Perry, senior author of the paper and a professor of environmental and occupational health
"In addition to exposure to this pesticide, children and other vulnerable groups are also increasingly exposed to other pesticides and these chemicals may act synergistically to produce health problems."
