A new study conducted in Denmark has linked infertility to different types of pollution among men and women. While air pollution is associated with increased infertility risk in men, noise pollution leads to a higher risk of infertility in women. 

The study, published in the BMJ, drew from a database of 526,056 men and 377,850 women aged 30 to 45 who had less than two children, were cohabiting or married and had lived in the Nordic country between 2000 and 2017. The study did not include sterilised men and women who had undergone surgery to prevent pregnancy. 

The study stated that men exposed to air pollution over an average of five years had a higher risk of infertility, which further adds to evidence about the impact of fine particulate matter on human health. 

“Based on a nationwide cohort, designed to include a high proportion of people actively trying to achieve pregnancy, we found that PM2.5 was associated with a higher risk of an infertility diagnosis among men,” the study noted. 

As for infertility among women aged 35 to 45, noise pollution was the leading cause of infertility.  

“Road traffic noise was associated with a higher risk of an infertility diagnosis among women older than 35 years, and possibly among men older than 37 years,” the study added. 

During the 18-year period, infertility was diagnosed in 16,172 men and 22,672 women. Exposure to levels of PM2.5 that were 2.9 micrograms per cubic metre higher than average over five years was associated with a 24 per cent increased risk of infertility. 

“As many western countries are facing declining birthrates and increasing maternal age at the birth of a first child, knowledge on environmental pollutants affecting fertility is crucial,” the study stated. 

“If our results are confirmed in future studies, it suggests that political implementation of air pollution and noise mitigations may be important tools for improving birthrates in the western world.”

Infertility is defined as a lack of conception after at least a year of regular, unprotected sexual intercourse. Apart from pollution, infertility is linked to tobacco and alcohol use, sexually transmitted infections, various chronic conditions and diseases, obesity, and severe underweight. 

Exposure to environmental factors, such as pesticides, and ionising radiation, are also suspected risk factors for infertility. 

(With inputs from agencies)