The study by researchers from the Chinese University of Hong Kong found that high levels of air pollution were also associated with poor sperm quality and may also be responsible for a sharp drop in male fertility, The Guardian reports.
The scientists studied the sperm count of almost 6,500 men, and found a “strong association” between increased levels of particulate air pollution and “abnormal sperm shape.”
Their report was published in the journal Occupational & Environmental Medicine and said that though the effect is “relatively small in clinical terms,” it could nevertheless lead to infertility for a “significant number of couples” considering the high levels of air pollution in major cities around the world.
“We found a robust association between exposure to PM2.5 air pollution and low percentage of sperm normal morphology in reproductive-age men,” wrote the researchers.
“Although the effect estimates are small and the significance might be negligible in a clinical setting, this is an important public health challenge,” they added.
The study analyzed men in Taiwan aged 15-49 between 2001-2009, assessing sperm count and the level of fine particulate pollution caused by automobiles, construction dust and wood-burning near study participant’s homes. Researchers said they found a strong association between PM2.5 exposure and the shape of sperm.
Why is the study important? Because, The Guardian noted further, sperm counts among men have been cut in half over the last four decades, though researchers aren’t yet sure why. And fertility experts viewed the latest air pollution research with some caution.
As the news site reported further:
Allan Pacey, professor of andrology at the University of Sheffield, welcomed the report but said that although the findings “may seem quite interesting” the assessment of “sperm size and shape [sperm morphology] is one of the most difficult tests to carry out on sperm and therefore can be less accurate. Moreover, many doctors and scientists now believe that on its own poor sperm morphology is probably not as clinically relevant as we once thought it was.”
Also, Richard Sharpe, a male reproductive health expert and professor at the University of Edinburgh noted he was “thoroughly underwhelmed” by the results of the Chinese study.
“Sperm morphology is highly variable, both between men and within the ejaculate of an individual man … So changes of the order of magnitude reported here in association with exposure to fine particulate matter are unlikely to be of any great relevance to likely fertility, as the authors admit,” he told The Guardian.
Researchers noted that theirs was an observational study, meaning there are no firm conclusions to be drawn about cause and effect. Also, they noted they did not have any information on previous fertility problems involving any of the study participants.
Still, Pacey noted that the findings were important in understanding one potential cause of male infertility. (Related: Excessive Laptop Computer Use Linked To Male Infertility.)
“From this and other studies,” he told The Guardian, “I remain of the opinion that air pollution probably does have the potential to negatively influence male reproductive health."
He added that “the jury is still out about quite how and to what extent this impacts on male fertility, rather than measurable and small interesting changes in semen quality.”
In April of this year, Natural News reported that there was a rise in male infertility around the world that seems to be taking place below the radar of most societies.
Also, as reported by Natural News in April 2014, a previous report from the World Health Organization blamed air pollution for the deaths of seven million people annually. But a separate study by researchers at Columbia University and Chongqing Medical University linked toxic air pollution to developmental problems in infants beginning in the womb.