Exposure to air pollution increases the chances of having low birth weight in babies and the risk can be mitigated if pregnant women live in greener spaces, a new study has found.

Studies have shown that children with low birth weight are at an increased risk of asthma and chronic obstructive pulmonary diseases (COPD) as they grow older.

The latest study highlights the importance of reducing pollution and increasing green spaces in residential areas for the health of future generations. The findings were published in BMC Medicine.

Researchers used data from the Respiratory Health in Northern Europe (RHINE) study, which contains information about 4,286 children and their mothers. The study measured the greenness of the areas using satellite images and the pollution in the area in terms of five pollutants: nitrogen dioxide, ozone, black carbon and two types of particulate matter (PM2.5 and PM10).

The team compared the birth weights of children born to pregnant women exposed to various levels of pollution and found that higher levels of air pollution were linked with lower birth weight. The average reductions in birth weight were 56g, 46g, 48g and 48g for PM2.5, PM10, nitrogen dioxide and black carbon respectively.

"The time when babies are growing in the womb is critical for lung development. We know that babies with lower birth weights are susceptible to chest infections, and this can lead to problems like asthma and COPD later on," said Robin Mzati Sinsamala, who presented the study at the European Respiratory Society International Congress in Italy on Sunday.

"Our results suggest that pregnant women exposed to air pollution, even at relatively low levels, give birth to smaller babies. They also suggest that living in a greener area could help counteract this effect. It could be that green areas tend to have lower traffic or that plants help to clear the air of pollution, or green areas may mean it's easier for pregnant women to be physically active," Sinsamala said.

Professor Arzu Yorgancioğlu, the chairperson of the European Respiratory Society Advocacy Council, said the study adds more evidence to the impact of air pollution on human health.

"This study adds to a growing body of evidence on the damage that air pollution is having on our health, especially in vulnerable babies and young children. Women who are pregnant will want to protect their babies from potential harm. However, as individuals, it can be difficult to reduce our exposure to air pollution or make our neighborhoods greener," explained Yorgancioğlu, who was not involved in the study.

"As doctors and researchers who care about children's health, we need to put pressure on governments and policymakers to lower the levels of pollution in the air we breathe. This study also suggests that we could help to mitigate some of the effects of pollution by making our neighborhoods greener," Yorgancioğlu added.