PM2.5 Pollution in North India: Sources and Health Risks
Why in the news
A Nature Communications study mapped where northern India’s fine particle pollution comes from and stressed local control in traffic and biomass-burning areas.
Key facts
- PM2.5: solid and liquid particles of 2.5 micrometres or less.
- Delhi: mainly ammonium chloride and organic aerosols from vehicles, household heating and fossil fuels.
- Elsewhere: ammonium sulfate, ammonium nitrate and biomass burning organic aerosols.
- Traffic gives only 40% of organic aerosols at urban roadsides.
| Period | Finding |
|---|---|
| Winter | Cow dung burnt for warmth and cooking adds night-time organic aerosols; levels reach 10-fold the warm months due to more emissions and a shallow boundary layer. |
| All year | Vehicle-linked hydrocarbon-like aerosols persist; urban oxygenated aerosols come from vehicles and cooking. |
Way forward
- Cut primary emissions from incomplete combustion.
- Use separate urban and rural strategies covering vehicles, heating and industry.
Exam angle
- Journal: Nature Communications.
- Related terms: oxidative potential, boundary layer, biomass burning.