Common air pollutants may cause subtle DNA changes in developing sperm that could impact male reproductive health, according to new research [1].

These findings suggest that environmental factors play a more significant role in male fertility than previously understood. By identifying specific pollutants that alter gene activity, researchers can better understand the epigenetic drivers of infertility and potential risks to future generations.

The research, which included Professor Richard Lea of the University of Nottingham, spanned four years [1]. The team investigated whether exposure to air pollution during the critical stages of sperm development could trigger epigenetic changes, which are modifications that affect how genes are expressed without changing the DNA sequence itself [1], [2].

According to the study, ozone and nitrogen dioxide showed the strongest links to these biological changes [1]. The researchers said they observed subtle DNA modifications in sperm that was still developing, suggesting that the male reproductive system is sensitive to atmospheric toxins during the maturation process [1], [3].

The findings were presented at the 42nd Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE) in 2026 [2], [3]. The presentation highlighted the need for further investigation into how these specific pollutants interact with the male reproductive system over time.

While the study identifies a correlation between pollutants and DNA changes, the researchers said they focused on the potential for these alterations to impair overall fertility [1], [2]. The work adds to a growing body of evidence regarding the impact of urban environments on human biology.

“Ozone and nitrogen dioxide showed the strongest links to these biological changes.”

This research indicates that male fertility is not only influenced by genetics and lifestyle but is also susceptible to external environmental stressors. If common urban pollutants like nitrogen dioxide can alter the epigenetic markers of sperm, it suggests that air quality standards have direct implications for public reproductive health and the biological viability of offspring.