(Beyond Pesticides, November 29, 2011) New research shows that women who drink water containing the widely used herbicide atrazine may be more likely to have irregular menstrual cycles and low estrogen levels, even at concentrations far below federal drinking water standards considered safe by the U.S. Environmental Protection Agency (EPA). Researchers compared women living in Illinois farm towns where atrazine is used regularly to women living in Vermont where the herbicide is used sparingly, and found that the women in Illinois were almost five times more likely to report irregular menstrual cycles, including more than six weeks between periods. Consumption of over two cups of unfiltered Illinois water daily was associated with increased risk of irregular periods.
The study, entitled â€śMenstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water,â€ť was published in the journal Environmental Research earlier this month, and is based on municipal tap water tested between July and September of 2005. In the study, participants maintained menstrual cycle diaries, answered a questionnaire, and provided daily urine samples for analyses of luteinizing hormone and estradiol and progesterone metabolites. To measure exposure, analysts looked at the state of residence, concentrations of atrazine and chlorotriazine in tap water, municipal water and urine, and estimated dose from water consumption.
According to researchers, the average concentration of atrazine in Illinois water was 0.7 parts per billion (ppb) â€“ which is well below EPAâ€™s standard of 3ppb. Whatâ€™s more alarming is that co-author Lori Cragin, Ph.D. says that drought conditions at the time of sampling for this study in 2005 would have slowed the runoff from farm fields.
Beyond Pesticides submitted comments to EPA earlier this month in response to a petition by the group Save the Frogs urging the agency to ban atrazine. In Beyond Pesticidesâ€™ comments, several studies are highlighed that have been published in the scientific literature since EPA began reevaluating atrazine under its registration review process in 2009. This research includes a 2011 study published in the journal Environmental Health Perspectives, showing that prenatal exposure to atrazine is linked to small head circumference and fetal growth restriction; a study published in the journal Reproductive Toxicology in 2010 finds male rats prenatally exposed to low doses of atrazine are more likely to develop prostate inflammation and to go through puberty later than non-exposed animals; and, a 2010 study published in the Proceedings of the National Academy of Sciences finds that male frogs exposed to atrazine can become so completely female that they can mate and lay viable eggs.
Even at low levels that are considered â€śsafeâ€ť by EPA standards, atrazine is known to harm fish, and has been associated with reproductive and developmental effects as well as endocrine disruption. 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.
As the most commonly detected pesticide in rivers, streams and wells, an estimated 76.4 million pounds of atrazine are applied in the U.S. annually. It has a tendency to persist in soils and move with water, making it a common water contaminant.
Source: Environmental Health News
All unattributed positions and opinions in this piece are those of Beyond Pesticides.