A recent study published in Nature Communications used data on stillbirths and air pollution between 1998 and 2016 from 54 low and middle income countries including India, Pakistan and Nigeria and concluded that air pollution causes almost a million stillbirths a year. The report estimated that approximately half of stillbirths recorded could be caused by exposure to pollution particles smaller than 2.5 microns (PM2.5) that are mostly produced from the burning of fossil fuels. Nearly all the mothers included in the study were exposed to PM2.5 levels above the WHOs current guideline level of 5 micrograms per cubic metre (g/m3). Researchers also found that an increase in PM2.5 exposure of about 10 g/m3 was associated with an 11 per cent increase in the risk of stillbirth.Overall, the study covered 137 countries in Asia, Africa and Latin America where 98 per cent of stillbirths occur. Polluted air is a known factor that leads to an increase in the risk of stillbirths but this global study is the first to assess the number of deaths. Even though it isnt clear how air pollution causes this, researchers believe that pollution particles pass through the placenta and cause irreversible embryonic damage that in some cases, harms the placenta itself. Air pollution may also hamper the ability of the mothers body to pass on oxygen to the foetus and the study followed another 2022 study where researchers found toxic air pollution particles were found in the lungs and brains of foetuses.The solution is, of course, clean air policies but in addition to this, vulnerable pregnant women can also take some steps to protect themselves against pollution like wearing masks, installing air purifiers and avoiding going outside when air pollution occurs.