A scientific study revealed that air pollution is as bad for pregnant women as smoking in raising the risk of miscarriage, the Guardian newspaper reported.
Air pollution is already known to harm fetuses by increasing the risk of premature birth and low birth weight. Recent research has also found pollution particles in placentas.
The effect of long-term exposure to dirty air on the risk of miscarriage has been analyzed previously in studies from Brazil to Italy to Mongolia that found a link, but others failed to do so. However, the latest study is the first to assess the impact of short-term exposure to air pollution.
The study found that raised levels of nitrogen dioxide (NO2) pollution that are commonplace around the world increased the risk of losing a pregnancy by 16 percent. NO2 is produced by fuel burning, particularly in diesel vehicles.
"It's pretty profound," said Dr. Matthew Fuller, at the University of Utah’s department of emergency medicine and one of the research team.
"If you compare that increase in risk to other studies on environmental effects on pregnancies, it’s akin to tobacco smoke in one third miscarriages,” he added.
The research, published in the journal Fertility and Sterility, was conducted in Salt Lake City in the US, and surrounding urban areas. But Fuller said the results were applicable elsewhere: "There are many places in the world that suffer from pollution that is far greater, so this is not a problem unique to Utah. This is a problem we are all facing."
NO2 levels in Salt Lake City are similar to those in cities, such as London and Paris.
Fuller was initially alerted to the issue when a family member lost a miscarried during a particularly poor period of air quality in 2016.
He said: "That triggered the question in my mind and then I started noticing anecdotally that I was seeing spikes in miscarriage numbers in the emergency department during and after pollution spikes."
