A recent study in the journal Environmental Research determined that exposure to course particles (PM10), fine particles (PM2.5), and ozone during an entire pregnancy were all associated with preterm birth (gestational age <37 weeks). The increased risk for PM10/coarse particles was 1.09, the increased risk for PM2.5/fine particles was 1.24, and the increased risk for ozone was 1.03. All were statistically significant, meaning that the results are unlikely to be due to chance.
Particulate air pollution is also known as soot, it comes from burning fuels (cars, trucks, power plants, etc.). Ozone is also known as smog, it is formed on hot days in a chemical reaction from oxygen, vehicle exhaust and sunlight.
