Pollution harms men's fertility, but traffic noise affects women's

Roughly one in six people are affected by infertility worldwide.

And with more than half the world's population now living in urban areas, researchers are interested in whether living in noisy and polluted cities could be to blame.

A new study in Denmark has used nationwide data to explore infertility.

It found long-term exposure to air pollution and traffic noise may be associated with higher infertility — but these factors affect men and women differently.

What do pollution and noise do to the body?

We know traffic pollution has undeniable impacts on the environment. Its negative effects on human health are also well established, with links to cancers and heart disease.

Inhaled chemicals from polluted air may also travel to the reproductive tract via the blood. They can reduce fertility by either disrupting hormones or causing direct damage to eggs and sperm.

Effects of traffic noise on Health are less clear, but some research suggests this affects stress hormones, which could alter fertility.