Describe the key points of the revised Global Air Quality Guidelines (AQGs) recently released by the World Health Organisation (WHO). How are these different from its last update in 2005? What changes in India’s National Clean Air Programme are required to achieve these revised standards ?
Introduction
The WHO's 2021 Global Air Quality Guidelines (AQGs) tightened pollutant limits based on new health evidence, challenging India's air quality management.
Key Revisions and Differences from 2005 AQGs
The 2021 AQGs drastically reduced recommended limits for key pollutants, emphasizing no safe exposure level for particulate matter. PM2.5 annual guideline halved from 10 µg/m³ (2005) to 5 µg/m³, and 24-hour from 25 µg/m³ to 15 µg/m³. PM10 annual limits reduced from 20 µg/m³ to 15 µg/m³, and 24-hour from 50 µg/m³ to 45 µg/m³. Other pollutants like O3, NO2, SO2, CO also saw stricter guidelines.
Required Changes in India's National Clean Air Programme (NCAP)
- Revise NCAP targets for alignment with stricter WHO 2021 standards.
- Enhance monitoring, robust source apportionment studies.
- Implement regional air quality management, stricter emission standards.
- Strengthen inter-sectoral coordination.
Conclusion
Meeting these stringent global benchmarks is vital for India's public health and sustainable environmental goals.
129 words · target ~150
The directive 'describe' requires a detailed account of the key features, differences, and necessary changes related to the WHO Air Quality Guidelines and India's NCAP.
Suggested structure
Introduction to WHO AQGs and India's air pollution challenge
Key points of the revised Global Air Quality Guidelines (2021)
Differences between 2021 and 2005 WHO AQGs
Required changes in India's National Clean Air Programme (NCAP)
Conclusion: Importance of stringent air quality standards
Key points
The 2021 WHO AQGs significantly tightened recommended limits for key pollutants (PM2.5, PM10, O3, NO2, SO2, CO) based on new scientific evidence of health impacts at lower concentrations.
For PM2.5, the annual guideline was halved from 10 µg/m³ (2005) to 5 µg/m³ (2021), and the 24-hour guideline from 25 µg/m³ to 15 µg/m³.
For PM10, the annual guideline was reduced from 20 µg/m³ (2005) to 15 µg/m³ (2021), and the 24-hour guideline from 50 µg/m³ to 45 µg/m³.
The revised guidelines emphasize that no safe level of exposure exists for certain pollutants, particularly particulate matter, and introduce interim targets.
India's NCAP needs to revise its current targets (20-30% reduction by 2024 from 2017 levels) to be more ambitious and align with the significantly stricter WHO 2021 standards.
NCAP requires enhanced monitoring networks, robust source apportionment studies, regional air quality management plans, stricter emission standards across sectors, and stronger inter-sectoral coordination to meet the revised global benchmarks.
Common mistakes
Lack of specific figures for WHO 2005 vs. 2021 guidelines for key pollutants.
Providing generic solutions for NCAP without specifically linking them to achieving the *revised* WHO standards.
Not clearly distinguishing between the *key points* of the revised guidelines and their *differences* from 2005.
Overlooking the comprehensive nature of the revised guidelines (e.g., including O3, NO2, SO2, CO, not just PM).
Difficulty: Hard — Requires specific factual knowledge of WHO's 2005 and 2021 Air Quality Guidelines (including specific pollutant limits and their changes) and the ability to critically analyze India's National Clean Air Programme in light of these revised international standards.