Researchers link male fertility to air pollution
Exposure to particulate matter in air pollution may be a factor influencing the quality and fertility of sperm in men, according to a recent study.
"Fine particles contain many toxic chemicals, such as heavy metals and polycyclic aromatic hydrocarbons, which have been found to be harmful to sperm quality in laboratory and animal studies," said senior researcher Xiang Qian Lao.
"The shape and size of sperm is an important factor for fertility," he said.
The researchers studied exposure to very fine particles in air pollution in the short and long term. These fine particles can penetrate the lungs and even the bloodstream.
This type of particle can be found inside and outside the home and most often is caused by vehicle exhausts, wood burning, crops, coal, oils or emissions from power plants and other industries.
The research team analyzed the medical examination records and health questionnaires of approximately 6,500 Taiwanese men aged 15 to 49 who participated in the medical examination program between 2001 and 2014.
Semen samples were taken and sperm quality was assessed based on their total number, size, shape and mobility.
Because men usually take 3 months to produce new sperm, the researchers used participants' addresses to estimate their exposure to particulate matter over a 3-month period and average exposure within two years.
The researchers found that the proportion of non-normal sperm cells increased by 18 percent during near-term exposure and by 26 percent in the long term.