Exposure to air pollution increases the risk of infertility, according to American research
Exposure of mothers and fathers to common air pollutants can increase the risk of infertility because it can be harmful to the development of eggs, sperm and embryos. new research finds in the US.
Previous papers have found that exposure to air pollution likely contributes to infertility, but it is unclear whether the toxins affect men or women because both parents face similar exposure. That also made it difficult to determine when in the conception process the damage occurred.
The new study examined about 1,400 men and women who were trying to have a child through in vitro fertilization. This allowed researchers to look at donor eggs, which turn into eggs, and sperm, which were developed separately and in physically different areas.
It was widely believed that air pollution harmed women more, but new research shows that fathers’ exposure is also a problem.
“We don’t normally think about male partner exposure in the preconception window, but we and others are increasingly showing that male exposure is important, both in terms of fertility, and potentially later in children’s health outcomes,” says Audrey Gaskins , a researcher from Emory University and lead author of the study.
The article looked at air quality data in participants’ zip codes and at fertilizer clinics to determine exposure to a range of pollutants. It found that exposure to organic carbon and particles during egg and sperm development cycles is most strongly associated with deleterious effects on egg survival, fertilization and embryo quality.
Particulate matter is a common air pollutant produced by diesel vehicles, power plants and other industrial facilities, as well as by smoke from wildfires. The Environmental Protection Agency this year lowered the threshold at which it takes action to reduce levels, as research shows the substance is more toxic than previously thought.
Gaskins cited a potential real-world example in previous research showing that wives of traffic police officers in India, where air pollution is high, had less successful pregnancies.
Exposure to organic carbon, a component of particulate matter, during ovarian stimulation, the period in in vitro fertilization when ovulation is medically induced, appeared to increase the chance that eggs would not survive. The contaminant also appeared to affect folliculogenesis and spermatogenesis, which are crucial steps in egg and sperm development.
“The study really underlines that even these short-term exposures during critical periods are important,” Gaskins said.
Wildfire smoke is rich in organic carbon, so areas affected by the fires are of particular concern, she added.
Even the air quality in the clinic seemed to matter. The study found that higher levels of organic carbon on the day of egg thawing were associated with lower egg survival, while higher levels of ozone were associated with lower fertilization rates. That correlation was found even though clinics generally have air filtration systems.
The study also found no effects on the process for several air pollutants, such as nitrogen dioxide.
Those trying to conceive can take a number of steps to protect themselves, such as using a Hepa indoor filtration system, or using high Merv (minimum efficiency reporting value) furnace filters that tackle particulate matter. Gaskins also recommended avoiding high-traffic areas and staying indoors on days when air pollution is particularly high.