Nitrogen dioxide (NO2) is a chemical mainly produced by vehicle emissions. It can also be present indoors from cigarette smoke or butane and kerosene heaters and stoves. (Related: Unprecedented science study proves that air pollution can negatively affect babies while in the womb.)
For the review, researchers at the University of Aberdeen in the U.K. looked at over a decade’s worth of scientific evidence from around the world to measure the effects of mothers’ exposure to everyday substances, including air pollutants, alcohol, and diet on the size of the unborn baby. These were measured through ultrasound from halfway through the pregnancy onward.
The studies in the review date back 13 years, when the first studies linking exposure to fetal measurements were first published. Seven studies from different countries, including the U.S., Australia, and several European countries measured air pollution which was linked to fetal size.
However, in all the studies, evidence showed that in the third trimester, exposure to NO2 reduced fetal growth. This can increase the child’s risk of heart disease, Type 2 diabetes, and asthma.
"Our research has shown that the link between exposure and fetal growth is apparent well before birth, so any potential interventions need to happen in the early stages of pregnancy," said Professor Steve Turner, the lead author of the study.
Turner and his team suggested that their findings indicated that public health measures are needed immediately to reduce the exposure of pregnant mothers to NO2.
Researchers all over the world have studied how air pollution affects pregnancy for years now. Here are some other consequences that researchers have found:
Exposure to air pollution is something you can avoid or minimize. To reduce your exposure to air pollution, you can get an air purifier, place air-purifying plants inside your home, and avoid using contaminants such as hair spray and paint as much as possible.