PRETERM BIRTH IN INDUSTRIAL CITY OF INDIA, KANPUR: A CASE STUDY OF THE EFFECT OF AIRBORNE PARTICULATE MATTER OF PM2.5 OR LESS

Anindita Bhattacharya and Alka Tangri*

ABSTRACT

Scarcely any examinations from western countries have connected pre-birth to particulate matter < 2.5 μm (PM2.5) with increased risk of congenital anomalies. However, the outcomes are of mixed opinion. In this review study, the information of all pregnant ladies women laboured in public hospitals during 2017–2018 in Kanpur, an industrial city of the country were matched with the data of daily average PM2.5, nitrogen dioxide (NO2), sulphur dioxide (SO2) and ozone (O3) concentrations of the nearest monitoring station. A time-dependent exposure over the entire pregnancy for each woman was calculated. The study used a time varying Cox proportional hazards model to explore the association between PM2.5 exposure and the risk of congenital anomalies, after adjusting for individual confounders and other pollutants. A total of 9386 singleton live births were included in the study, and 127 (1.35%) were with congenital anomalies. An increase of every 10 μg/m3 in PM2.5 exposure over the entire pregnancy was significantly associated with increased risk of congenital anomalies, with hazard ratio (HR) of 1.35. For subtype analyses, PM2.5 exposure exhibited a significant association with cardiac anomalies and other unclassifiable anomalies with HRs of 1.60 and 1.42 respectively. The impacts of PM2.5 exposure on orofacial anomalies and musculoskeletal anomalies were not significant. The results indicate high concentration of PM2.5 could increase the risk of congenital anomalies among Indians, especially for cardiac anomalies. Self-protective measures involving reducing PM2.5 pollution exposure during pregnancy as well as environmental policies aiming to restrict PM2.5 emission could be helpful to reduce the burden of cognitional anomalies.

Keywords: PM2.5 exposure; Congenital anomalies; Cardiac anomalies.