Pollution driving premature deaths across cities in South Asia: Study
Rajeev Choudhury
Increasing levels of PM2.5 particulate matter in the air driven by anthropogenic activities are driving up premature deaths in cities across South Asia, researchers of a new study published in the journal Science Direct said.
The study was undertaken by the researchers from the universities of Birmingham, Harvard and Brussels analysed satellite data from 46 cities in tropical Africa, the Middle East, and Asia that are projected to become megacities with a population of over 10 million by 2100, and found that the concentration of nitrogen dioxide (NO2) have increased in as many as 41 cities between 2006 and 2018.
The increase in NO2 concentration, which has the potential to lead to increases in PM2.5 by forming aerosol nitrate, has been found to be significant in 34 cities with Dhaka and Chittagong in Bangladesh recording a two and three-fold increase during the study period.
The study further revealed that across nine cities in the region there has been a 1.3 times increase in premature death that could be attributed to air pollution.
Moreover, during the study period, the average rate of premature deaths as compared to deaths from all causes rose from 3.48% in 2005 to 41.35% in 2018, the data reveal.
Aerosol Optical Depth (AOD), which is the measure of aerosols like urban haze, smoke particles etc. is seeing a steep rise in the South Asian cities during the study period, the researchers wrote in the paper.
The researchers further noted that since dust from the Thar Desert makes a negligible contribution to AOD trends across the rest of India, the increase in AOD is because of a substantial increase in PM2.5, due to increased formation of secondary inorganic aerosols resulting from increases in sulphur dioxide emissions primarily resulting from coal-burning and nitrogen oxides caused by burning of petro products.
In 2018, exposure to PM2.5 and nitrogen dioxide can be attributed to additional 1.8 lakh premature deaths in the 46 cities studied, which is a 62% rise over the 2005 numbers, the researchers noted.
