Science
Scientists warn of male reproductive crisis as data shows testosterone halved and air pollution linked to sperm DNA changes
July 13, 2026 at 07:23 PM · Updated 95d ago
Coverage
4 reports · over 103 hours
TGThe Guardian
‘Spermageddon’: is the world facing a male reproductive crisis?
(opens the publisher’s site)
TGThe Guardian
Is male testosterone in freefall? – podcast
(opens the publisher’s site)
TGThe Guardian
Men’s average testosterone levels have halved in last 50 years, say scientists
(opens the publisher’s site)
TGThe Guardian
Air pollution linked to DNA changes in sperm, research shows
(opens the publisher’s site)Researchers presented data at a European conference showing a 54% decline in average testosterone levels since 1972 and a separate study linking air pollution to epigenetic changes in sperm.
- Scientists presented findings at the European Society of Human Reproduction and Embryology meeting showing average testosterone levels in men declined by 54% between 1972 and 2019.
- A separate study presented at the same meeting linked exposure to ozone and nitrogen dioxide to changes in sperm DNA methylation, which can affect gene expression.
- Prof Hagai Levine, who led the testosterone analysis, said the decline indicates a "major crisis in male reproductive health."
- Prof Allan Pacey, who was not involved in the air pollution study, said the observed changes are measurable but it is not yet possible to conclude they are clinically meaningful for male infertility.
Latest developments
- Researchers said rising obesity and diabetes, along with possible environmental factors like endocrine-disrupting chemicals and global heating, have contributed to the testosterone decline.
- Scientists called for further investigation and policy responses to address what they described as a male fertility crisis.