MIT, Harvard researchers link small-scale actions to improved air quality in India

A new study by Massachusetts Institute of Technology (MIT) and Harvard University researchers shows how small-scale actions could improve air quality and health outcomes in India. 

The study by researchers identifies targeted and cost-effective methods to mitigate the harmful environmental impact from crop residue burning in India. 

According to the study, after harvesting rice, Indian farmers typically burn the leftover straw to prepare for planting wheat, releasing harmful carbon monoxide, ozone, and fine particulate matter (PM2.5) into the air, which causes health risks and raises rates of premature deaths throughout South Asia. 

Researchers attributed between 44,000 and 98,000 premature deaths annually from exposure to PM2.5 as a result of crop residue burning. Farmers largely have ignored government regulations intended to curtail crop residue burning. 

Researchers used computer models to determine when and where the most harmful crop residue burnings were taking place and found that approximately 67-90% of PM2.5 related-deaths are the result of crop residue burning in the states of Punjab, Haryana, and Uttar Pradesh. They say roughly 40% of India’s annual air-quality impacts came from crop residue burning from six districts within Punjab.

The study proposes that small changes could have huge impacts on air quality and health outcomes. Researchers estimate a 14% improvement in air quality and 10,000 deaths averted annually if Punjab farmers would burn crop residues two hours earlier in the day. 

They also proposed that farmers could adopt rice varieties that require less residue burning, such as basmati rice. 

“Our findings show that targeted and potentially inexpensive interventions could go a long way toward mitigating the public health impacts of crop residue burning in India,” said Sebastian Eastham, a lead author of the study and a principal research scientist at the MIT Joint Program on the Science and Policy of Global Change.  

The research team is preparing to present a comprehensive cost-benefit analysis of its proposed recommendations, along with other incentives, to farmers.