Exposure to Common Herbicide Linked to Rare Birth Defect

A common herbicide used in the United States increases the risk of choanal atresia, a nasal disorder, among newborns, researchers from the Baylor College of Medicine have found.

The culprit has been identified as atrazine, a commonly used herbicide in corn crops.

Choanal atresia blocks the back of the nasal passage by tissue formed during fetal development. It is a rare condition but can be serious because it affects a baby's ability to breathe. It is typically treated through surgery.

According to the researchers, only very few risk factors for choanal atresia have been identified. But they believe that certain chemicals present in the atrazine weed that disrupts the mother's endocrine system could be associated with risk of developing choanal atresia.

"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 Philip Lupo, assistant professor of pediatrics-hematology/oncology at the Baylor College of Medicine.

To prove the link between atrazine and choanal atresia, researchers studied the health conditions of children who were exposed to the herbicide and those who were not.

The study found that mothers who lived in Texas counties with the highest levels of estimated atrazine application were 80 percent more likely to have children with choanal atresia or stenosis compared to women who lived in the counties with the lowest levels. Choanal stenosis is a less severe form of the condition.

Atrazine may affect the endocrine system by copying the activity of certain hormones in the body, thus blocking their activity and disrupting normal biological processes. While the latest findings were significant, scientists stressed that more research is needed before making any new policy recommendations, according to a Medical Daily report.

"Our results warrant more detailed exploration before any public health or policy-related recommendations are made but this study is a good first step in trying to understand the origin of this birth defect, including a possible role of atrazine," Lupo said.