Limits have been reduced to less than half for six key pollutants; new guidelines clear proof of the damage air pollution causes to health, even at lower concentrations, says WHO
In a “turning point” for the countries tackling air pollution, the World Health Organisation (WHO) released revised and more stringent global Air Quality Guidelines. In the first update since 2005, ahead of COP26, the limits have been reduced to less than half for six key pollutants for the governments to set their own standards. The WHO said the guidelines provide clear proof of the damage air pollution causes to health, even at lower concentrations than previously understood.
The annual PM2.5 levels have been halved to 5 ug/m3 from 10 ug/m3 (2005), while the daily mean has been set at 15 ug/m3 from 25 ug/m3 (2005). Annual PM 10 limit is now 45 ug/m3 compared to 50 ug/m3 (2005). The annual O3 limit has been slashed to 10 from 40 ug/m3. The annual nitrogen dioxide (NO2) limit has been reduced to 10 compared to 40 in 2005, and the daily limit has been set at 25. While the daily SO2 limit has been doubled from 20 of 2005 to 40 now, carbon monoxide (CO) has been set at 4 mg/m3.
|India needs to act fast|
Evidence shows dirty air prematurely kills 7 million per year worldwide–more than 2 million in South East Asia alone. India’s current national limits are much above the WHO’s non-binding guidelines and more relaxed than those set by other South Asian countries. How difficult will it be to match new norms? The current, much relaxed targets, have not been met across hundreds of cities emitting varying degrees of pollutants. Is setting variable limits the answer? Experts call air pollution a global health emergency. They say India urgently needs to align its air quality standards with its public health policy.
‘Single standard won’t suit varied demography’
India is among the top 3 most polluted countries in the world, preceded by Bangladesh and Pakistan, but its national air quality standards are more relaxed compared to WHO guidelines and other Asian countries. For example, the PM 2.5 standard in Bangladesh is 15 (annual mean limit) and 65 (daily limit), in Pakistan it is 15 (annual) and 35 (daily). India’s PM2.5 standard is 40 (annual) and 60 (daily).
Experts pointed out India not only has to tighten the standards, but also differentiate them to match the health needs of its “varied demography”. SN Tripathi, professor at the Indian Institute of Technology, Kanpur, and steering committee member, National Clean Air Programme (NCAP), said: “India has to strengthen its health data and revise the National Ambient Air Quality Standards accordingly. Raw health data is required to conduct a large range of health studies vis-a-vis air pollution impacts for India’s varied demography, exposure and differing PM2.5 composition. A single exposure prevention response will not suit the Indian population.”
Need a regional plan for South Asia “as early as possible”
In South Asia, the daily and annual levels of key pollutants are way above the WHO standards. Will the new norms stir the region’s governments into taking stronger action with a regional plan?
Experts pointed out that 90% of the world’s population is exposed to pollution higher than that permitted by the WHO, but for South Asia, the exposure is 100%. Among 100 global cities, 92 exceeded WHO’s revised 2021 air quality guidelines. Delhi’s annual PM2.5 trends in 2020 was 16.8 times more than WHO’s 2021 guidelines of 5 ug/m3, while Mumbai’s exceeded 8-fold, Kolkata 9.4-fold, Chennai 5.4-fold, Hyderabad 7-fold and Ahmedabad 9.8-fold.
According to Arvind Kumar, founder, Lung Care Foundation & chairman, Institute of Chest Surgery, Chest Onco Surgery and Lung Transplantation, the time to act was yesterday. Now air pollution is a health emergency, with the worst impacts in South Asia and fossil fuels are the root of it.
Kumar said, “Governments across South Asian countries need to urgently align their national air quality standards with the latest WHO guidelines and take a regional approach, keeping health at the heart of actions to tackle and resolve the air pollution crisis…we need to commit to do anything and everything that it takes to solve this crisis as early as possible.”
‘Severe health harm done’ under WHO’s previous PM2.5, NO2 limits
Scientists said there was an urgent need to revise the standards as the 2005 standards were highly inadequate to stop the havoc pollutants such as NO2, emitted by vehicles and coal plants, were wreaking on the health of children.
Lauri Myllyvirta, lead analyst, Centre for Research on Energy and Clean Air (CREA), said PM2.5 and NO2 pollution severely harmed even at levels far below the current 2005 guideline levels. “For example, meeting the current  guidelines everywhere in the world would do little to protect the estimated four million children per year that develop asthma due to NO2 exposure.”
Analysts said adherence to the new guidelines will require a revolutionary shift in the energy sector, which will include tighter emissions standards for power plants, industries and vehicles. Joshua Miller, modelling centre manager, The International Council on Clean Transportation, said the implications for the transport sector are significant as it is a major source of NO2 and a significant contributor to PM2.5 and ozone pollution. “Meeting the guidelines will likely require accelerating the retirement of vehicles, equipment, and ships with older-technology engines—especially diesel engines—and replacing these with advanced emission-control and zero-emission technologies,” he said.
Data showed that 1 in 5 deaths worldwide is caused by air pollution from burning oil and coal. Experts said countries at the forthcoming COP26 must commit to phase out fossil fuels. Aaron Bernstein, interim director of the Centre for Climate, Health, and the Global Environment at Harvard TH Chan School of Public Health, said air pollution causes children to have asthma, it causes pneumonia, it causes pregnant women to have babies born prematurely and with more birth defects, and it’s increasing the risk of people who are dying from COVID-19 right now. “Burning fossil fuels harms everybody, but especially the poor because air pollution makes the very injustices we are trying to combat worse. At COP26, the world must urgently commit to phasing out fossil fuels so we can deliver the healthier, more just, and sustainable world that our kids deserve,” Bernstein said.
India has set a target of reducing air pollution by 20-30% in its cities under NCAP. The country’s National Ambient Air Quality Standards (NAAQS), last revised in 2009, permits cities to set short-term targets through assessment of local sources of air pollution. Experts said India must swiftly revise its own policy. Like the WHO, will India align targets with greater consideration on health impacts in the proposed 2022 NAAQS update? Will the new WHO norms push the government to act? Experts said, however difficult, it must be done sooner rather than later.