This is the first revision in the global air quality by WHO since 2005. In the new guidelines, WHO has lowered the acceptable exposure levels to key pollutants, including ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide and particulate matter (PM).
The health risks associated with particulate matter equal or smaller than 10 and 2.5 microns (µm) in diameter (PM₁₀ and PM₂.₅, respectively) are of particular public health relevance. Both PM₂.₅ and PM₁₀ are capable of penetrating deep into the lungs but PM₂.₅
can even enter the bloodstream, primarily resulting in cardiovascular
and respiratory impacts, and also affecting other organs. PM is
primarily generated by fuel combustion in different sectors, including
transport, energy, households, industry, and from agriculture. In 2013,
outdoor air pollution and particulate matter were classified as
carcinogenic by WHO’s International Agency for Research on Cancer
(IARC).
New guidelines:
- WHO has lowered acceptable thresholds for several pollutants, including PM 2.5. Now, PM 2.5 concentrations must remain below 15µg/m³.
- According to the new limits, average annual PM2.5 concentrations should not be higher than 5 micrograms per cubic meter.
- Air pollution kills at least 7 million people prematurely each year. The revised guidelines encourage countries to slash fossil fuel emissions.
- These guidelines are not legally binding on countries. The reduced level of air pollution will improve the health of people.
In India
- India continues to remain one of the most polluted countries in the world. Air pollution has become the main threat to health in many countries.
- The average concentration of PM2.5 in 2020 in New Delhi was 17 times higher than the recommended levels.
- The pollution level is also higher than the recommended levels in Mumbai, Chennai, and Kolkata.
