July 7, 2026

expert reaction to conference abstract from ESHRE exposure to air pollution mixtures during spermatogenesis and sperm DNA methylation in men seeking infertility treatment

An unpublished conference abstract presented at ESHRE looks at air pollution, spermatogenesis and DNA methylation. 

Prof Richard Lea, Professor of Reproductive Biology, University of Nottingham, said:

“This is an important piece of research that adds to a growing body of evidence that sperm quality is adversely affects by air borne pollutants.

“Since there is currently increased public, academic and clinical awareness around pollutant effects on reproductive health, the release of this work in abstract form is timely.

“Although air pollution is recognised as a major route of exposure with studies beginning to emerge in the literature, few studies have directly addressed this by identification of differentially methylated genes in sperm. The research is of good quality, and the analytical techniques are robust and account for confounders. Limitations are clearly acknowledged and the press release summary captures the design, results and overall message well.

“The authors have identified the risk of a type 1 error in their analyses which is experimentally valid. They have focused on a defined population of individuals in one broad location which is a logical approach given the pollutant evaluation. Analysis of a further sample and full replication of the study is ultimately needed.” 

Prof Allan Pacey, Professor of Andrology at the University of Manchester, said:
“There has been growing evidence in recent years that aspects of human health can by impacted by air pollution, and this includes male infertility. However, we have not really understood much about the likely mechanism by which this occurs. In this study, the authors looked at changes to DNA methylation patterns in sperm and suggest there are clear differences between men who were exposed to air pollution mixtures and those that were not. These include differences in the methylation of key genes which are known to control for sperm production. Whilst I have only seen the abstract of this work, it appears to have been very thoroughly done. However, at the present time it is not possible to conclude whether the observed changes to sperm DNA methylation are clinically meaningful for male infertility and further work will need to be done to confirm or refute that.”

‘Exposure to air pollution mixtures during spermatogenesis and sperm DNA methylation in men seeking infertility treatment’ by C. Nobles et al. was presented at ESHRE. 00:01 UK time on Tuesday the 7th of July 2026. 

Declared interests

Prof Allan Pacey:  “AAP is a member of the Cryos International External Scientific Advisory Committee. In the last two years he has also undertaken consultancy for Carrot Fertility, and has delivered educational lectures for IBSA Institut Biochemique SA, and Mealis Group but all monies were paid to the University of Manchester. He is also the co-chair of the UKNEQAS Reproductive Sciences Advisory Committee, is a member of the Advisory Boards for the Progress Educational Trust (Charity Number 1139856) and the Science Media Centre (Charity Number 1140827) and Patron of the Fertility Alliance (Charity Number 1206323 (all unpaid). He is a member of the Guidelines Development Groups for the National Institute for Health and Care Excellence, and the World Health Organisation (again all unpaid).”

Prof Richard Lea: “My primary research area concerns pollutant effects on male reproduction and I am a member of the Society for Reproduction and Fertility. I have no conflicts of interests to declare.”