Exposure to common air pollutants can alter gene activity in sperm cells, potentially affecting male fertility, pregnancy outcomes, and the health of future children. This conclusion was reached by researchers who presented their results at the annual meeting of the European Society of Human Reproduction and Embryology.
The study analyzed data from more than two thousand men in Salt Lake City, Utah, collected between 2013 and 2017.
- Participants provided semen samples:
- at enrollment in the study;
- then after 2, 4 and 6 months.
- DNA methylation analysis of sperm cells was conducted for 1220 people who completed the 6-month follow-up.
- Scientists assessed each participant’s exposure to mixtures of outdoor pollutants during the spermatogenesis period (about 3 months), including:
- ozone (O₃);
- nitrogen dioxide (NO₂);
- sulfur dioxide (SO₂);
- PM2.5.
A total of 39 DNA methylation changes associated with mixtures of air pollutants were identified, with ozone and nitrogen dioxide emerging as the most significant factors. Of particular interest was a change in the GNAS gene, which is associated with poorer semen quality and plays an important role in fetal development.
Study lead Dr. Kerry Nobles noted that exposure to pollutants at key stages of sperm cell formation is associated with methylation changes, including in genes involved in spermatogenesis and early development.
Professor Karen Sermon added that these data help explain why couples exposed to polluted air more often face difficulties conceiving. 🌫️