Pollutants implicated in births of more girls than boys.

• Author: Herro, Alana
• Position: EYE ON EARTH - Emissions and dioxins associated with inverted sex ratio - Brief article

A recent study found that residents of Canadian communities who were exposed to emissions from nearby polluting industries gave birth to more females than males, a reversal of the normal sex ratio. This is likely due to high levels of common air pollutants called dioxins and is not a surprise, according to study author James Argo, a medical geographer with the IntrAmericas Centre for Environment and Health. "There is a very strong association between chronic exposure to dioxins and an inverted sex ratio," he said.

The abnormal sex ratios became apparent when Argo looked at the genders of children born to parents who lived within 25 kilometers of a polluting industry, such as an oil refinery, metal smelter, or pulp mill. The percentage of girls was higher in all of the nearly 90 communities surveyed; in some communities, residents gave birth to as few as 46 males for every 54 females, compared to a normal sex ratio of 51 males for every 49 females. Chronic exposure to dioxins "interferes with the process of conception," so people who have been exposed for over...