What is PM 2.5?
PM2.5, or fine particulate matter, is a type of air pollution that can cause serious health problems. It’s made up of tiny solid particles and liquid droplets that are 2.5 micrometers or less in diameter.
Main Highlights from Study Published in Nature Communications
- Sources of PM2.5 vary with sites
- Delhi: Major sources include ammonium chloride and organic aerosols from vehicles, residential heating, and fossil fuel use.
- Beyond Delhi, bulk contribution includes ammonium sulfate, ammonium nitrate, and biomass burning organic aerosols.
Oxidative Potential and Health Risks
- PM2.5 oxidative potential has much to do with health risk indicators mainly due to organic aerosols from inefficient biomass and fossil fuel burning.
- By the same measure, traffic emissions contribute only 40% to organic aerosols at urban roadside locations.
- Hitherto, the toxicity of PM2.5 was five times worse in India compared to that of Chinese and European cities.
Air Quality Variations from Season to Season
- Winter
- Poor ambient air quality from burning cow dung for heating and cooking has increased cold season organic aerosols, especially at night.
- This winter shows increases in concentration up to 10 fold in comparison with the warm months, mainly due to much more emissions and a shallower boundary layer.
- All of the year Wind Blend
- Consistent seasonal characteristics: hydrocarbon like organic aerosols from vehicular emission.
- Urban oxygenated organic aerosols resulted from both fossil (vehicles) and non fossil (cooking) sources.
Policy Recommendations and Implications
- It will significantly reduce exposure to PM2.5 by reducing primary emissions due to incomplete combustion.
- Spatially and specially target strategies for urban and rural areas to address vehicle emissions, residential heating, and industrial pollution.
The study revealed the necessity for local air pollution control in Northern India, especially in high traffic and biomass burning areas, to prevent the most severe health impacts.
Source: The Hindu
