Common Herbicide May Increase Risk of Rare Disorder in Infants

(Beyond Pesticides, October 2, 2012)

The herbicide atrazine may be linked to an amplified risk of choanal atresia, a congenital abnormality of the nasal cavity, according to researchers at Baylor College of Medicine and other Texas institutions. Choanal atresia is recognized when tissue formed during fetal development blocks an infant’s nasal cavity. Though it is a rare condition, it is considered quite serious because it can affect an infant’s ability to breathe.

The study, scheduled for publication in The Journal of Pediatrics, focused on atrazine because, although there are very few risk factors for choanal atresia, endocrine disrupting chemicals are suspected to be associated with the condition. “Endocrine disrupters aren’t fully understood, but it is believed they interfere with or mimic certain hormones, thereby blocking their proper function and potentially leading to adverse outcomes,” said Dr. Phillip Lupo, lead author of the study. Looking at mothers from Texas counties with the highest levels of estimated atrazine application, researchers discovered that they are 80 percent more likely to have children with choanal atresia or stenosis (a less severe form of the condition) than compared to mothers who live in counties with the lowest levels.

The herbicide atrazine and over 50 other active pesticide ingredients have been identified as endocrine disruptors by the European Union and endocrine disruptor expert Theo Colborn, PhD. The body’s hormone producing glands -the thyroid, gonads, adrenal and pituitary glands- produce hormones such as thyroxine, estrogen, testosterone, and adrenaline in order to guide human growth, development, reproduction, and behavior. These glands and the hormones they produce comprise our endocrine system. Endocrine disruptors are a serious cause for concern due to their potential for wide ranging effects on our health. These chemicals have the potential to mimic human estrogen, block the reception of certain hormones, and effect the concentration of natural hormones in our body. Endocrine disruption is implicated in numerous adverse health effects. Suspected endocrine disrupting chemicals have been linked to attention deficit hyperactivity disorder, Parkinsons, diabetes, Alzheimers, cardiovascular disease, obesity, early puberty, infertility, and childhood and adult cancers. A 2004 study links endocrine disrupting pesticides to birth defects and adverse impacts on neurological development in infants whose mothers have been exposed to the chemical.

A more recent 2012 study reveals that even minute doses of endocrine disrupting chemicals can have significant effects on human health. Unfortunately, our regulatory structure does not adequately protect people from these possible human health effects. Given reports finding traces of these chemicals in indoor air, schools, drinking water supplies, and urine, many Americans are in uncharted territory when it comes to the future of their health. The U.S. Environmental Protection Agency’s (EPA) largest move in this area came in 2007; a full 10 years after Congress mandated regulatory authorities to determine a mechanism to screen for these chemicals. When EPA did propose testing, the experiments performed were criticized by many as being outdated.

Atrazine is used nationwide to kill broadleaf and grassy weeds, primarily in corn crops, but also in turf management. Beyond endocrine disruption, the chemical has been implicated in a wide range of human health effects, including cancer, neurotoxicity, and kidney and liver damage. A study by the U.S. Geological Survey found atrazine in approximately 75 percent of stream water and 40 percent of groundwater sampled near agricultural areas. Earlier this year, U.S. Representative Keith Ellison (D-Minn.) reintroduced a bill that (H.R.4318) would ban the production, sale, importation or exportation of any pesticide containing atrazine. However, as it currently stands, nearly 10 years after atrazine was banned in the European Union, the chemical is still sold in the United States.

Source: Baylor College of Medicine Press Release