(Beyond Pesticides, August 26, 2009)
The commonly used herbicide atrazine can spike at extremely high levels which go undetected by regular monitoring, according to new report by the Natural Resources Defense Council (NRDC), Poisoning the Well. Currently, the U.S. Environmental Protection Agency (EPA) considers an annual average atrazine level of below 3 parts per billion to be acceptable for human consumption, although studies have shown adverse health impacts below EPA’s “safe” levels. The analysis by NRDC discovered that in the 139 municipal water systems from which EPA collected data on a biweekly basis in 2003 and 2004, atrazine is found 90% of the time. Furthermore, 54 of these water systems have at least one spike above 3 parts per billion.
“The data shows that EPA is unable to adequately regulate atrazine and protect the public from this hazardous herbicide in our drinking water,” said Jay Feldman, executive director of Beyond Pesticides. “With studies showing hormonal and other adverse effects at extremely low levels, any level of atrazine in our drinking water is dangerous and spikes above EPA’s 3 ppb threshold are completely unacceptable. EPA must put public health first and ban this toxic chemical.”
Under the federal Safe Drinking Water Act, municipal water supplies are tested for chemicals about four times a year. Because this is done so infrequently, EPA mandates that companies manufacturing a chemical, in this case, Syngenta for atrazine‚ must monitor drinking water in a sample pool of towns as much as once a week. A New York Times investigation finds, however, that too often reports of these spikes of atrazine in the drinking water go unreported to residents or fail to reflect the higher concentrations.
The town of Piqua, Ohio was found to have concentrations of atrazine at 59.57 parts per billion in April of 2005 by Syngenta, with similar levels in 2004 and 2007. In a report sent to citizens in 2005, though, the highest level was said to be 11.6 parts per billion. Residents were also not told when or for how long these peaks occurred. Syngenta claims that they provided city officials in Piqua with results, yet city officials are unaware of this.
EPA asserts that it does not believe these one-time spikes are of concern to human health; however, plenty of evidence exists suggesting otherwise.
“Our biggest concern is early-life-stage development,” says Jennifer Sass, senior scientist at NRDC. “These endocrine disruptors act in the body at extremely low levels. These spikes matter.”
Earlier this year, a study published in the medical journal Acta Paeditrica found that the highest rates of birth defects for U.S. babies occur when conception occurs in the spring and summer months, when the highest concentrations of pesticides are found in surface waters. The correlation between the month of the last menstrual period and higher rates of birth defects is statistically significant for half of the 22 categories of birth defects reported in the Centers for Disease Control database from 1996 to 2002, including spina bifida, cleft lip, clubfoot and Down’s syndrome. The study relies on findings by the U.S. Geological Survey, the EPA and other agencies on the seasonal variations in nitrates, atrazine and other pesticides in the surf
ace water.
Even at levels considered “safe” by EPA drinking water standards, atrazine is linked to endocrine-disrupting effects. Research by UC Berkeley professor, Tyrone Hayes, Ph.D., demonstrates that exposure to doses of atrazine as small as 0.1 parts per billion, turns tadpoles into hermaphrodites – creatures with both male and female sexual characteristics.
Atrazine has also been implicated in a study as a possible cause for male infertility, blocking the action of the male sex-hormone testosterone and could impact the development of male reproductive organs in humans.
In yet another study last year by Dr. Rick Relyea, Ph.D., an associate professor of biological sciences in the University of Pittsburgh’s School of Arts and Sciences, a mixture of small amounts of ten of the most commonly used pesticides, including atrazine killed 99 percent of the leopard frog tadpoles that he was testing.
While EPA is aware of these new studies, the agency will not review the research until sometime next year, and in the meantime has not warned pregnant women about the risks of atrazine or to use a simple carbon water filter.
“The public believes that the EPA has carefully reviewed all the chemicals that are used and has the authority it needs to deal with risks, but that’s often not the case,” says Erik D. Olson, director of food and consumer product safety at the Pew Charitable Trusts.
While atrazine is one of the most common agricultural pesticides in the U.S., runoff from lawns and gardens is a serious concern. Dr. David Skelley, Ph.D. a professor of ecology at the Yale School of Forestry and Environmental Studies, discovered last year that intersex frogs are more common in suburban areas than agricultural areas. His research focused on specific chemicals, such as atrazine which is increasingly used to manicure home lawns and gardens.
Pesticides, such as atrazine, even at low levels, have been associated with reproductive and developmental effects as well as endocrine disruption. Atrazine is the most commonly detected pesticide in rivers, streams and wells, with an estimated 76.4 million pounds of atrazine applied in the U.S. annually. Atrazine has a tendency to persist in soils and move with water, making it a common water contaminant.
