Kolkata, a city in India, continues to struggle with hazardous air quality despite national efforts to improve air quality. A recent study by the Bose Institute found a strong correlation between ultrafine particulate matter (PM2.5) and rising toxicity levels, with biomass and solid waste burning identified as key contributors. The study analyzed the oxidative potential of PM2.5, which refers to its ability to produce reactive oxygen species in human lungs, leading to oxidative stress and severe respiratory and cardiovascular problems.
The research found a non-linear pattern in toxicity levels, with a sharp spike in oxidative potential between concentrations of 70-130 µg/m³ PM2.5. This plateau suggests that once PM2.5 concentrations exceed 130 µg/m³, toxicity levels do not continue to increase, likely due to the overwhelming of the body’s natural antioxidant defenses.
Using Positive Matrix Factorization, the team identified biomass and solid waste burning as the primary sources of toxicity in PM2.5, despite efforts to reduce emissions from other sources such as vehicular emissions and construction waste. The city’s air quality continues to suffer due to the legacy of biomass emissions, with the National Clean Air Programme (NCAP) unable to make a significant impact.
The study’s findings have prompted local authorities to take stricter measures to curb waste burning activities. The researchers urge more targeted efforts to address pollutant sources that disproportionately affect public health, as India spends billions of rupees on clean air missions. To achieve sustainable clean air goals, it is essential to eliminate high-toxicity sources like biomass burning in cities like Kolkata.