Two studies published in international journals have reported a worrying link between air pollution levels and the incidence of type 2 diabetes in Chennai and Delhi. The study is notable not because the findings are new – they aren’t unprecedented – but because they have found that the link, which has been indicated in Western countries and more recently in China as well, also holds in urban India.
Indian cities have consistently dominated the tops of lists of places with the worst air for residents, with air quality frequently several times higher than the limits set by the World Health Organisation.
The new studies are part of the Centre for cArdiometabolic Risk Reduction in South Asia (CARRS) Surveillance Study. Here, researchers roped in 6,722 adults in Chennai and 5,342 in Delhi and tracked their health through questionnaires and blood samples, with which they checked for fasting plasma glucose (FPG) and glycosylated haemoglobin (HbA1c), at specific intervals from 2010 to 2016.
