A recent quantitative summary of thirteen studies provides new ‘suggestive evidence’ that exposure to ambient air pollution during pregnancy heightens the risk of stillbirth particularly during the third term of pregnancy. This study was just published on the Occupational and Environmental Medicine which is one of the top journals in environmental health.
The effects of air pollution on stillbirth have been studied especially in developed countries and the summary results from previous two reviews were inconsistent due to limited number of studies available. By summarising and analysing the body of evidence with a substantial number of new studies the authors were able to show that a 4 µg/m3 increase in small particulate matter of less than 2.5 in diameter (PM2.5) and a 10 ppb increase in exposure to nitrogen dioxide (NO2) are associated with a 2.0% and 6.6% increased risk of stillbirth respectively, while exposure to carbon monoxide, PM10 and ozone were also linked to a heightened risk.
Nevertheless though the authors conclude that “The body of evidence suggests that exposure to ambient air pollution increases the risk of stillbirth”, they also call for the future studies to strengthen the evidence. In 2015, there was an estimated 2,6 million stillbirth globally but yet it is one of the neglected global health issues. If future research confirms the association of air pollution and stillbirth; it would be of major public health importance.
Furthermore, stillbirth as well as any adverse health effect caused by air pollution are obviously preventable by increasing awareness through health sector and reduction of air pollution through implementation of policies on control of vehicular emissions, fuel quality improvement and control of industrial waste emission.
The study was conducted by Doctoral Students Nazeeba Siddika (MPH), Hamudat A. Balogun (MSc) along with Dr Adeladza K. Amegah (PhD) and Professor Jouni J. K. Jaakkola (MD, PhD) at Center for Environmental and Respiratory Health Research (CERH), University of Oulu, Finland.
Siddika N, Balogun HA, Amegah AK, Jaakkola JJK. Prenatal ambient air pollution exposure and the risk of stillbirth: systematic review and meta-analysis of the empirical evidence. Occupational and Environmental Medicine 2016 (doi 10.1136/oemed-2015-103086).
More information: Jouni J. K. Jaakkola, Professor of Public Health and Director of the Center for Environmental and Respiratory Health Research (CERH), University of Oulu.
Email: jouni.jaakkola(a)oulu.fi, mobile: +358 40 6720 927
Last updated: 1.7.2016