WASHINGTON: Exposure to air pollution, even for a short term, may significantly increase the risk of miscarriages, a study has found.
Air quality has been associated with numerous adverse health outcomes from asthma to preterm birth . Researchers at the University of Utah in the US found women living along the most populous region in the state of Utah had a higher risk (16%) of miscarriage following short-term exposure to elevated air pollution.
The study, published in‘Fertility and Sterility’, consisted of over 1,300 women (54% Caucasian, 38% Hispanic , and other/ missing 8%; average age 28 years).
The women in the study sought help at the emergency department following a miscarriage (up to 20-weeks gestation) between 2007 to 2015.
The team examined the risk of miscarriage during a three- or seven-day window following a spike in the concentration of three common air pollutants: small particulate matter (PM 2.5), nitrogen dioxide and ozone .
The study excluded women who lived outside Utah.
“We are really only seeing the most severe cases during a small window of time,” said Claire Leiser, from University of Utah.
The results suggest there could be an increased risk for an individual. The team found a 16% increased risk in miscarriage for women exposed to elevated levels of nitrogen dioxide.
Although small particulate matter does track with nitrogen dioxide, these results did not significantly associate with an increased risk of miscarriage.
The team conducted a case cross-over study that estimated a woman’s risk of miscarriage multiple times in a month where air pollution exposure varied. This approach removed other risk factors, like maternal age, from the study.
Scientists were unable to ascertain the age of the fetus at the time of the miscarriage and were unable pinpoint a critical period when the fetus may be most vulnerable to pollutants.
“While we live in a pretty unique geographic area, the problems we face when it comes to air pollution are not unique. As the planet warms and population booms, air pollution is going to become a bigger problem not only in the developing world but across the US,” said Matthew Fuller, assistant professor of Surgery and senior author on the paper