Air pollution, particularly with tiny particles (PM2.5), is associated with bad sperm quality and may increase the chance of infertility for a man, according to a new Chinese scientific study. Although the clinical impact is relatively small, given the spread of the pollution problem internationally, Chinese scientists warn that a significant number of couples around the world are likely to have difficulty having a child because of this reason.
The researchers, led by Dr. Shiang Kian Lao of the Hong Kong Public School of Public Health, who published the publication in the Occupational & Environmental Medicine magazine, analyzed data for nearly 6,500 men aged 15 to 49 in Taiwan.
A close correlation has been found between the existence of semen with anomalies (in size and morphology) and the exposure of a man at high levels of air pollution at his place of residence. For every five micrograms per cubic meter of air (5 μg / m3) increase in air content with particles up to two and a half million meters (PM2.5) over a two-year period, there was a significant decrease in normal spermatozoa by approximately 1.3%.
On the other hand, it was found that pollution is associated with increased sperm counts, possibly as a counterbalance to their negative effect on size and shape. Similar findings in morphology and sperm counts were also found when a man’s exposure to pollution did not exceed three months.
Through just the biological mechanism, pollution is related to sperm growth, it remains unclear. Previous studies in experimental animals have however shown that many microparticulate components, such as heavy metals and aromatic hydrocarbons, cause damage to the semen.