Over 9 million lives could be saved by meeting WHO air pollution norms: Study

More than 9.4 million lives in low- and middle-income countries could be saved annually if WHO air quality guidelines for PM2.5 are met, according to a new study. Researchers found that cleaner air would also reduce major diseases and generate significant economic gains through lower healthcare costs and higher productivity.

New Delhi: More than nine million lives across low- and middle-income countries could be saved by following the WHO’s recommended annual guidelines for air pollution, a study has estimated.

The United Nations’ health agency recommends a maximum annual value of five micrograms per cubic metre for PM2.5 and a maximum of 10 micrograms per cubic metre for nitrogen dioxide (NO2).

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PM2.5 is particulate matter sized 2.5 microns or less in diameter, tiny particles small enough to be inhaled deep into the lungs. Vehicle emissions, industrial processes and construction dust are among its major sources. Nitrogen dioxide is a key pollutant arising from burning fossil fuels.

Researchers, including those from the UK’s University of Cambridge, said ambient air pollution is a global health risk, but disproportionately affects people in low-and middle-income countries (LMICs), where air quality has deteriorated in line with large-scale urbanisation, economic development and an increasing use of cars and motor vehicles.

Outdoor air pollution has been linked to increases in heart and lung diseases, including coronary heart disease, stroke, asthma, chronic obstructive pulmonary disease and dementia. Other than exacting a mental toll on individuals and families, the diseases also have a substantial economic toll in terms of healthcare costs and lost productivity.

Meeting the World Health Organization’s (WHO) guidelines would also bring substantial savings from reduced illness, including lower healthcare costs and increased productivity, as individuals would take less time off work due to preventable illness, the team said.

Their paper, published in the journal Environment International, looked at the potential health and economic benefits of improving air quality in 136 LMICs, focusing on PM2.5 and NO2.

The researchers combined detailed data from air pollution, population size and health with published evidence on the links between pollution, mortality and disease.

“Estimated health impact of attaining WHO IT3 (interim target 3) and AQG (air quality guidelines) concentrations for PM2.5 was 16.04 per cent reduction (6.58 million (lives)) and 22.97 per cent reduction (9.43 million (lives)) in annual mortality, respectively,” the authors wrote.

Economically, the annual mortality reductions translated into IntD 5.5 trillion (7 per cent of aggregate LMIC GDP) and IntD 8.4 trillion (10.7 per cent of GDP), respectively. One IntD or international dollar is a hypothetical currency, having the same purchasing power as a United States dollar within the US at a given point in time.

For NO2, about 4,35,000 lives and 1.1 million lives across LMICs could be estimated to be saved under the IT3 and AQG scenarios, respectively, yielding gains of IntD 0.6 trillion (0.7 per cent of LMIC GDP) and IntD 1.5 trillion (1.9 per cent of LMIC GDP).

Disease-specific mortality reductions were found to be most prominent for ischaemic heart disease and stroke in Asia and Africa.

Under the PM2.5 AQG scenario, an estimated 2.82 million COPD, 1.10 million dementia, 7.3 million ischaemic heart disease, and 2.3 million stroke reductions in annual incidence were projected.

Author Annalan Navaratnam, clinical research fellow at the University of Cambridge, said, “Tackling air pollution is likely to have a huge impact on improving quality of life and reducing the number of early deaths.”

“For the first time, we’ve been able to model the potential benefits of the WHO’s clean air guidelines across countries with the highest levels of outdoor air pollution, both in terms of the millions of lives that could be saved every year and the potential economic and societal benefits,” Navaratnam said.