Taking cognizance of the rapidly rising global air pollution, which has become a pressing issue for governments across the globe, for the first time in 15 years, the World Health Organisation has updated its air quality guidelines on Wednesday.
The U.N. health agency released its revised guidance as climate change is the nucleus at the U.N. General Assembly in New York.
In the past two decades, with better monitoring and science the global picture about the effects of six major air pollutants on human health is much more clear. WHO states that 90% of the world’s people already live in areas with at least one particularly harmful type of pollutant.
“There is nothing more essential for life than air quality," WHO Director-General Tedros Adhanom Ghebreyesus said. “And yet, because of air pollution, the simple act of breathing contributes to 7 million deaths a year. Almost everyone around the world is exposed to unhealthy levels of air pollution.” Air pollution is now comparable to other global health risks like unhealthy diets and smoking tobacco, WHO said.
The 2005 guidelines- which were actually published a year later, prompted many countries to take action even though they are voluntary, WHO insists. Since then, evidence has grown about the negative impacts of air pollution on health based on improved pollution measurement systems and exposure assessments, leading to the update.
What are fresh WHO guidelines?
The WHO guidelines act as a reference for policymakers, advocacy groups and academics as they are not legally binding. The fresh guidelines change the advised concentrations of six pollutants which are known to have impacts on health- PM 2.5 and PM 10, as well as ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide.
In the guidelines, WHO has adjusted nearly all the levels downwards, warning that exceeding the new air quality guideline levels will lead to significant risks to health. At the same time, however, adhering to them could save millions of lives, it said. While a PM2.5 concentration of 25 micrograms per cubic metre in a 24-hour period was considered safe earlier, the WHO has now said that a concentration of over 15 micrograms is not safe.
WHO says globally more than 90% of the world population breathes air with PM 2.5 concentrations that exceed the recommended levels in its last guidelines, published in 2006. The fresh guidelines also slashed the PM 2.5 recommendation on an annual basis to 5 micrograms per cubic meter, down from 10 previously.
What are pollution levels in India?
India continues to remain one of the most polluted areas across the world, with harmful pollutant levels much higher than recommended. Greenpeace study found the average concentration of PM2.5 in 2020 in New Delhi to be nearly 17 times higher than the recommended levels. In Mumbai, pollution levels were eight times higher, in Kolkata, over nine times higher, and in Chennai, over five times higher.
Greenpeace India’s analysis of PM 2.5 data aggregated by IQAir found that at least 79 of the world’s 100 most populous cities breached the outgoing WHO annual mean PM 2.5 guidelines in 2020.
Polluted air is not only massive health and environmental concern but also takes a huge economic toll. According to the Health Effects Institute, in 2015, over 1.1 million premature deaths in India were caused by air pollution. ORF reported, in 2019, air pollution led to about a whopping 18 percent of all deaths in the country, this also triggered an economic loss of approximately 1.4 percent of GDP.
What are main sources of air pollution in India?
Sources of each pollutant vary, in terms of percent contributions from various sources. Dr Sarath Guttikunda, founder of Urban Emissions Info told the Centre for Policy Research (CPR) that the main sources contributing to air pollution are– vehicle exhaust, heavy industry including power generation, small scale industries including brick kilns, resuspended dust on the roads due to vehicle movement and construction activities, open waste burning, combustion of various fuels for cooking, lighting, and heating, power generation.
There are seasonal influences as well like dust storms, forest fires, open field fires during harvest season, and sea salt near coastal areas. And factors that contribute to air pollution all year round- from burning of diesel, petrol, gas, coal, biomass, and waste and resuspended dust.
As per CPR, for Delhi to ambient PM2.5 pollution, the contributions of includes- vehicle exhaust is up to 30%, biomass burning is up to 20%, soil and road dust is up to 20%, industries is up to 15%, open waste burning is up to 15%, diesel generators is up to 10%, power plants is up to 5% and urban airshed is up to 30%.