- The study was conducted among 6475 male participants aged 15–49 years
- Semen quality was assessed according to the WHO guidelines
- Exposure to PM2.5 leads to lower level of sperm normal morphology
New Delhi: In the last few years, researchers across the globe have unearthed a number of health risks associated with exposure to air pollution. Among them are acute and chronic respiratory diseases (including asthma and changes in lung function), cardiovascular diseases, adverse pregnancy outcomes, and even death. Regarded as a single biggest environmental killer by United Nations, air pollution claims over 6.5 million lives a year. Even World Health Organisation in 2013 concluded that air pollution is carcinogen to humans. Now, according to a new study done by researchers in Taiwan, exposure to fine particles in air pollution may affect men’s sperm quality and their fertility.
The researchers investigated the health effects of short-term and long-term exposure to fine particulate matter (PM2.5) on semen quality in Taiwanese men from the general population. The study was conducted among 6475 male participants aged 15–49 years who participated in a standard medical examination programme between 2001 and 2014.
Semen quality was assessed according to the WHO 1999 guidelines, including sperm concentration, total motility, progressive motility and morphology (the size and shape of sperm).
Since it takes about three months for a man to make new sperm, the researchers used each participant’s address as well as satellite data to estimate his exposure to PM 2.5 pollution over a this period, along with his average exposure over two years.
For every incremental exposure increase of 5 micrograms, researchers found that men’s sperm concentration increased slightly while their risk of abnormally shaped sperm rose by 18 percent with short-term exposure and 26 percent with long-term exposure. In conclusion, the study found a robust association between exposure to PM2.5 air pollution and low percentage of normal sperm morphology in reproductive-age men.
Although the effect estimates are small and the significance might be negligible in a clinical setting, this is an important public health challenge. But given the ubiquity of exposure to air pollution, a small effect size of PM2.5 on sperm normal morphology may result in a significant number of couples with infertility, the authors of the study write in BMJ Occupational and Environmental Medicine.
Researchers also advocated having global strategies on mitigation of air pollution to improve reproductive health as infertility has turned out to be a global health concern with about 48.5 million couples identified as infertile in 2010.