Scientists find link between noise pollution and male infertility

City boys considering fatherhood might want to consider a move to the countryside, as new research reveals that long-term exposure to noise could contribute to male infertility.

Whether it's rowdy neighbours, barking dogs, or living on a busy road, living and sleeping in a noisy environments can be a nightmare. Not only is noise pollution irritating, it has also been linked to health problems, including sleep disorders, heart disease, mental illness, and has been shown to change social behaviour and seriously interfere with concentration. Now, a new study has revealed that long-term exposure to even relatively low levels of noise (particularly at night) may contribute to the development of infertility in men. Previous research focusing on fertility in women has also shown a link between exposure to noise and birth-related problems, such as premature birth, miscarriage and birth defects. The study, published in Environmental Pollution, found that exposure above the WHO night noise level (55 dB - equivalent to the noise of a suburban street) was linked to a significant increase in infertility. Dr Jin-Young Min, the scientist behind the study, says it is important to consider noise when assessing environmental conditions that could contribute to infertility:

"Infertility is becoming a significant public health issue because of unexpected adverse effects on the health and quality of life and heavy expenditures on the health system. We know noise exposure has an effect on male fertility in animals, but our study is the first to show the risk of exposure to environmental noise on male infertility in humans."

Fertility problems affect one in six couples worldwide and can be down to a variety of causes, such as genetic abnormalities, infectious disease, environmental agents or certain behaviours. Dr Min looked at environmental exposure to noise, focusing on 206,492 men aged between 20 and 59. They calculated the levels of noise exposure using information from the men's postal codes. In the eight years covered by the study, 3,293 men had an infertility diagnosis. After adjusting the data for variables like age, income, BMI and smoking, the research team found that the chances of being diagnosed with a fertility problem were significantly higher in men exposed to noise over 55 dB at night (about as noisy as an air conditioner). Dr Min says that noise pollution is a more significant health issue than people might think:

"One of the biggest problems the world is facing today is environmental pollution; my special concern is what Theo Colborn described in her book Our Stolen Future: that the rapid decline in men's sperm counts in the 20th century was due to environmental pollution. If this trend continues, humans in the future will not be able to have normal pregnancy and childbirth. If you are a man and suffer from infertility, you need to consider exposure to environmental pollution as a risk factor."