What’s the news ?

• The World Health Organisation (WHO), in its first-ever update since 2005, has tightened global air pollution standards announcing more stringent limits for six pollutant categories such as particulate matter (PM), ozone (O3), nitrogen dioxide (NO2) sulfur dioxide (SO2) and carbon monoxide (CO) as impact of air pollution on health is much more serious than earlier envisaged.

News in detail

• Air pollution is considered the greatest environmental threat to health, and it disproportionately affects vulnerable populations and around 91% of deaths from ambient air pollution occur in low-income and middle-income countries.
• In India, 116,000 infant deaths in 2019 are attributable to air pollution, while burning coal combustion resulted in 100,000 deaths and ambient air pollution killed 16.7 lakh Indians.
• The government has a dedicated National Clean Air Programme that aims for a 20% to 30% reduction in particulate matter concentrations by 2024 in 122 cities, keeping 2017 as the base year for the comparison of concentration. 
• These are cities that do not meet the NAAQS when calculated from 2011 to 2015.
• As low-and-middle-income countries like India experience increased disparities in air pollution exposure due to large-scale urbanisation and economic development which has largely been driven by fossil fuels, it has resulted in an unequal burden of disease and mortality for its population. 
• Every year, exposure to air pollution is estimated to cause 7 million premature deaths and result in the loss of millions more healthy years of life.
• Globally, approximately 15% of deaths from Covid-19 are linked to PM2.5 air pollution.
• In 2013, outdoor air pollution and particulate matter were classified as carcinogenic by the WHO’s International Agency for Research on Cancer (IARC).
• 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.
• Findings by Greenpeace India show that of the 100 global cities in 2020, at least 92 exceeded the WHO’s revised 2021 air quality guidelines, which include 5 Indian cities as well. 
• Eg: Delhi’s annual PM2.5 trends in 2020 was 16.8 times more than the WHO’s 2021 guidelines of 5 ug/m3, while Mumbai’s exceeded 8-fold, Kolkata 9.4, Chennai 5.4, Hyderabad seven-fold and Ahmedabad exceeded 9.8-fold.

Revised norms

1. The upper limit of annual PM2.5 as per the 2005 standards, which is what countries now follow, is 10 ug/m3 has now been revised to 5 ug/m3.
2. The 24-hour ceiling used to be 25 microgram but has now been dropped to 15.
3. The upper limit of PM10, or particulate matter of size exceeding 10 microgram, is currently 20 microgram and has now been revised to 15, whereas the 24-hour value has been revised from 50 to 45 microgram.
4. NO2 levels, which are primarily attributable to vehicular emissions, have been revised to 10 ug/m3, in comparison to 40 ug/m3 in 2005. 

Additional Details

About NAAQS

• Ambient air quality refers to the condition or quality of air surrounding us in the outdoors. 
• National Ambient Air Quality Standards are the standards for ambient air quality set by the Central Pollution Control Board (CPCB) that are applicable nationwide.

The objectives of air quality standards are:  

1. To indicate the levels of air quality necessary with an adequate margin of safety to protect the public health, vegetation and property;  
2. To assist in establishing priorities for abatement and control of pollutant level;  
3. To provide uniform yardstick for assessing air quality at national level;  
4. To indicate the need and extent of monitoring programmes.

References:

1. https://www.thehindu.com/todays-paper/tp-national/who-tightens-global-air-quality-norms/article36621975.ece
2. https://www.hindustantimes.com/environment/who-revises-global-air-quality-sets-new-quality-levels-for-protection-of-health-101632316441576.html
3. http://www.arthapedia.in/index.php?title=Ambient_Air_Quality_Standards_in_India
4. https://cpcb.nic.in/upload/NAAQS_2019.pdf