A new study has found that air pollution could be a significant factor in male infertility, while noise pollution may affect women’s ability to conceive, especially those over the age of 35. The research, published in the BMJ, aimed to explore whether long-term exposure to air and noise pollution increased the risk of infertility in both men and women.
The Study’s Focus and Participants
The study analyzed data from 526,056 men and 377,850 women, all aged 30 to 45. The participants were chosen based on their lifestyle—many were cohabiting or married and had fewer than two children, making them likely to be trying to conceive. Importantly, the study excluded individuals who had undergone procedures like sterilization, which would naturally affect fertility.
Tracking Pollution and Infertility Rates
Researchers monitored each participant’s exposure to fine particulate matter (PM2.5), a form of air pollution, as well as road traffic noise levels. Pollution levels at participants’ home addresses were recorded between 2000 and 2017. Infertility diagnoses were tracked using Denmark’s national patient register.
Over the 18-year period, 16,172 men and 22,672 women were diagnosed with infertility. After accounting for various factors like income, education, and occupation, the researchers made some key discoveries.
Air Pollution’s Effect on Men
The study found that exposure to higher levels of PM2.5 (2.9 micrograms per cubic metre more than average) over five years increased the risk of infertility by 24% in men aged 30 to 45. This confirms previous concerns about the negative impact of air pollution on male fertility. While earlier studies had suggested that air pollution could lower sperm quality, those findings were often inconsistent. This new study, however, strengthens the link between air pollution and male infertility.
Noise Pollution’s Effect on Women Over 35
In contrast, PM2.5 was not linked to infertility in women. Instead, road traffic noise was the major concern. Women over 35 exposed to 10.2 decibels more road noise than average over five years had a 14% higher chance of experiencing infertility. For younger women, aged 30 to 35, noise pollution was not significantly linked to infertility.
Noise Pollution and Older Men
Interestingly, road noise also had a slight impact on men. Men aged **37 to 45** who lived in noisier areas experienced a small increase in infertility risk. However, for men younger than 37, there was no clear connection between noise pollution and infertility.
Implications for the Future
Infertility is a significant concern for many couples trying to conceive, with about one in seven couples in the UK facing fertility issues. The researchers emphasized that understanding how environmental factors like air and noise pollution affect fertility is crucial, especially as many Western countries see declining birthrates and older maternal ages at first childbirth.
If further studies confirm these findings, the researchers suggest that addressing air and noise pollution could help improve fertility rates in the Western world. They conclude, “Political action on reducing pollution could be an important tool for improving birth rates.”