Sulfur dioxide exposure linked to lower sperm count

In China, men’s sperm counts have plummeted by nearly 30% since 2001, a problem experienced worldwide. A new study conducted in the industrial city of Wuhan links that decrease to exposure to sulfur dioxide emitted from burning fossil fuels (Environ. Sci. Technol. 2017, DOI: 10.1021/acs.est.7b03289). Yuewei Liu of Hubei Provincial Center for Disease Control & Prevention and his team analyzed semen samples collected from 1,759 men who had visited Tongji Hospital between 2013 and 2015 seeking help to conceive a child with their partners. The researchers measured sperm concentration, total sperm, and total motile sperm in each sample, controlling for factors that might affect semen quality, such as age and smoking. The scientists then estimated the men’s exposure to air pollutants for the 90 days prior to semen collection using data from nine air-quality monitoring stations in Wuhan. Liu says that for each 10 µg/m³ increase in SO₂ exposure during the first stage of sperm development, sperm concentration dropped by 6.5%, total sperm count by 11.3%, and total motile sperm by 13.2%.