By Indira Aryal
Kathmandu, Oct. 24: Air pollution was the fourth leading risk factor for early death worldwide in 2019, exceeded only by high blood pressure, tobacco use, and poor diet, said a global study report on "State of Global Air 2020" (SOGA 2020).
The report was released by the Health Effects Institute (HEI) on Thursday.
The report highlighted that air pollution is the largest risk factor for death among all health risks, which is the first-ever comprehensive analysis of air pollution’s global impact on newborns. 
The report places Nepal among the top 10 countries with the highest outdoor pollution (PM2.5 levels) in 2019. With an annual average emission of 83.1 micrograms per cubic meters, (μg/3) of PM2.5 Nepal is second only after India.
According to the report, over 90 per cent of the world’s population experienced an annual average PM2.5 concentration that exceeded the World Health Organisation’s Air Quality Guideline of 10μg/m3. 
The report, which is being published annually by HEI, said that the long term exposure to pollution leads to heart disease, lung cancer, chronic obstructive pulmonary disease (COPD), lower respiratory infections such as pneumonia, stroke, type 2 diabetes and adverse birth outcomes among other adverse health impacts.
In Nepal alone, PM2.5 pollution killed 17,900 people in 2019. The total deaths due to air pollution during the year in Nepal exceeded 40,000 as per the report, with PM2.5 driving the most deaths in Nepal.
Talking to The Rising Nepal about the report, Bhupendra Das, researcher at IASS, Potsdam, Germany and Tribhuvan University, said that air pollution was a serious issue in South Asia, including Nepal.
The in-depth study on the association of air pollution with health is very primitive in Nepal, which is indispensable, he said. 
He said, “The ‘State of Global Air- 2020’ report presents a comprehensive analysis of air quality and health effects globally. As per the report, air pollution was the 4th leading risk factor for early death worldwide in 2019,” he said. 
Of the top 10 countries listed for the annual average of PM2.5 exposure for the year 2019, almost 50 per cent are from Asia. The report highlights the trend of ambient air pollution increasing upwards for South Asia, however, exposure due to indoor air pollution is declining annually.