How does air pollution increase the risk of infertility?

New research suggests that exposure to air pollutants may harm the development of eggs, sperm and embryos, increasing the risk of infertility.

According to The Guardian , previous studies have shown that exposure to air pollution can contribute to infertility, but it is unclear whether the toxins affect men or women more.

These studies also did not determine when the damage occurred during conception.

Pollutants affect fertility

It is often assumed that air pollution harms women more, but new research suggests that paternal exposure is also a problem.

The new study by US scientists looked at about 1,400 men and women who were trying to conceive using in vitro fertilisation (IVF). This allowed the researchers to look at how oocytes, which later develop into eggs, and sperm develop separately from each other, in different physical regions.

Exposure to air pollution may contribute to infertility - (Photo: REUTERS).

The authors looked at air quality data in the participants' homes and at fertility clinics.

Results showed that exposure to organic carbon and fine dust during egg and sperm developmental cycles had negative effects on egg viability, fertilization, and embryo quality.

'We don't often think about the effects of male exposure in the preconception period, but these effects are important, not only for fertility but also for the health of future offspring,' said Audrey Gaskins, a researcher at Emory University and lead author of the study.

Pollution "attacks" the clinic

Exposure to organic carbon, a component of fine dust, during ovarian stimulation appears to make it harder for eggs to survive, according to the researchers.

Fine dust is a common air pollutant created by diesel vehicles, power plants and other industrial facilities, as well as smoke from wildfires.

Gaskins said a previous study found that the wives of traffic policemen in India, where air pollution levels are high, had lower rates of successful pregnancies.

'The study highlights that short-term impacts during critical periods are also important ,' Gaskins said. 'Wildfire smoke contains a lot of organic carbon, so areas affected by wildfires need to be particularly concerned,' she added.

Even the air quality inside clinics has an impact. Research has shown that higher levels of organic carbon on the day of egg thawing are associated with lower egg survival rates, while higher ozone levels are associated with lower fertilization rates. This relationship was found even when clinics had air filtration systems.

The study found no significant effects of some other air pollutants such as nitrogen dioxide.

Those trying to conceive can take some protective measures, such as using a Hepa air filtration system in their home, or furnace filters with a high Merv rating to filter out fine dust, according to the study authors.

Also avoid crowded traffic areas, and stay indoors on days with high air pollution.