A new study points at a possible link between air pollution and a drop in sperm quality: “we can assume an exposition degrades the DNA of gametes.”
We knew that fine air particles were responsible for an increase in lung cancers, cerebrovascular accidents and heart diseases. But must we now add testicles to the list of organs who suffer from air pollution? This is the main conclusion of a Chinese study published on November 23rd in the specialized magazine Occupational & Environmental Medicine. “Air pollution is the world’s largest single environmental health risk,” said Dr Lao Xiang Qian, the study’s lead author and a researcher at the Chinese University of Hong Kong
The scientists who took part in the study have observed spermatozoids of about 6 500 men aged between 15 and 49, analysing their morphology, movement patterns and concentration levels between 2001 and 2014. At the same time, they matched it against the PM 2,5 fine particulate levels at their home addresses. The results showed “little” change induced by higher particle levels, however “considering the constant exposure to air pollution, the little effect induced by PM2,5 fine particles could be sufficient to cause infertility for a high number of couples”, according to the researchers.
The study shows that every 5-microgram increase of fine particles per cubic meter of air that lasts two years or more reduces spermatozoid size by 1,29 %. Such an effect was found “significant after a three-month exposure.” The team also noticed a simultaneous increase in the number of spermatozoids. They saw this as “compensation” for the drop in spermatozoid size. While some doubts still remain regarding the team’s conclusions, the scale of the study and the novel technology it used make their findings robust.
Professor Allan Pacey, an andrologist at the University of Sheffield flew in to support a “well-conducted study”. According to him, there should not be too much emphasis put on abnormally shaped sperm when assessing fertility. “From this and other studies, I remain of the opinion that air pollution probably does have the potential to negatively influence male reproductive health,” said Professor Pacey.
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