Air pollution linked to DNA changes in sperm, research shows — SkimNews
SkimNews Take
Identifying epigenetic rather than genetic changes in sperm suggests air pollution's reproductive harm can travel across generations without altering DNA itself — expanding the public health frame from personal fertility to inherited risk.
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- Dr Carrie Nobles of the University of Massachusetts Amherst led a study of more than 2,000 men in Salt Lake City between 2013 and 2017, tracking semen samples over six months alongside estimates of exposure to outdoor air pollutants during the three-month sperm production window.
- Researchers identified 39 DNA methylation changes linked to air pollution mixtures in the 1,220 men who provided a six-month follow-up sample, with ozone and nitrogen dioxide showing the strongest associations.
- The study, presented Tuesday at the European Society of Human Reproduction and Embryology meeting in London, highlighted the GNAS gene — previously linked to poorer semen quality and foetal development — as one of the affected imprinted genes that can persist beyond embryo development.
- Nobles said the findings suggest air pollution exposure during key stages of sperm development may be associated with changes in sperm DNA, while noting future work is needed to directly link these methylation changes to fertility outcomes.
- Prof Allan Pacey of the University of Manchester said the study demonstrated a measurable effect but cautioned it was not yet possible to conclude whether the observed changes are clinically meaningful for male infertility.
- Prof Richard Lea of the University of Nottingham called it an important addition to a growing body of evidence that airborne pollutants adversely affect sperm quality.
Why it matters: The research points to DNA methylation — chemical tags that regulate gene activity without altering the genetic code — as a plausible biological mechanism linking air pollution to declining male fertility, a link that has been suspected but mechanistically unclear. With 39 specific epigenetic changes identified and one (GNAS) previously tied to semen quality and foetal development, the study gives regulators and fertility researchers a concrete molecular target — though experts stress the clinical link to infertility remains unproven.
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