In a study conducted by IIT-Delhi, a link was found between mortality and the chemical species of PM 2.5. The study identified the 15 major components of PM 2.5 and tracked their emission sources such as emissions from biomass, coal, soil, etc. These factors were then correlated with the mortality rate of Delhiites over 24 hours.

“Association between acute exposure to PM2.5 chemical species and mortality in megacity Delhi” is the first study in India highlighting the dangers of PM2.5 and stressing the importance of guidelines to control their emissions to prevent health issues. The researchers stated that unlike developed countries such as the US, and Japan, metallic components are not a hazard in our nation. But the elementary carbon fossil combustion, emission, nitrates, sulfates, and related pollutants are the major risk species. They explained that nitrate and sulfates react with ammonia to form ammonium nitrate and ammonium sulfate, which increases the mortality rate to 2.4%, and 3.89% in a small duration of 24 hours respectively. 

Dey, Associate professor, Delhi-IIT stated that the males exposed to nitrate and sulfate were at high risk of developing comorbidities and cancer. However, in women, they saw an increased risk of mortality by 2.9% and 2.73% when exposed to elementary and organic carbon respectively.

(Source: https://health.economictimes.indiatimes.com/news/industry/why-pm2-5-emissions-are-deadlier-than-other-pollutants-for-delhiites/91275476)