Particulate air pollution a growing risk for premature death, disability globally: Study

The total number of premature deaths and years of disability from cardiovascular diseases attributable to particle air pollution rose from 2.6 million in 1990 to 3.5 million in 2019, a 31 per cent worldwide increase, according to a study.

The research, published on Wednesday in Journal of the American Heart Association, analysed particulate matter (PM) pollution as a risk factor for death and disability using freely available data from 204 countries collected between 1990 and 2019 and detailed in the Global Burden of Disease (GBD) study.

PM pollution consists of small particles of liquid and solids suspended in the air and inhaled into the lungs, such as vehicle emissions, smoke, dust, pollen and soot.

Exposure to PM pollution was estimated using a tool from the 2019 update to the GBD study that incorporated information from satellite and ground-level monitoring, computer models of chemicals in the atmosphere and land-use data.

The researchers from Tehran University of Medical Sciences in Iran analysed changes over time in years of life lost due to premature death (YLLs), years lived with disability (YLDs) and disability-adjusted life years (DALYs).

DALYs is a measure that considers both the loss of life and the impact on quality of life to assess the full impact of a health condition on a population.

The analysis found that the total number of premature deaths and years of cardiovascular disability from cardiovascular diseases attributable to PM air pollution rose from 2.6 million in 1990 to 3.5 million in 2019, a 31 per cent worldwide increase.

The increase in overall deaths was unevenly distributed, with a 43 per cent increase among men compared to a 28.2 per cent increase among women, the researchers said.

Between 1990 and 2019, there was a 36.7 per cent decrease in age-standardised premature deaths attributed to PM pollution, meaning that while fewer people had died from cardiovascular disease, people are living longer with disability, they said.

The study also found that regions with higher socioeconomic conditions had the lowest number of lost years of life due to cardiovascular disease attributed to PM pollution, yet also the highest number of years lived with disability.

The opposite was true in regions with lower socioeconomic conditions, with more lives lost and fewer years lived with disability, according to the researchers.

In all measures, increases in disability and death from ambient PM air pollution were higher in men than women, while declines in disability and death from household PM air pollution were lower in women than men, the study found.

"The declines in deaths may be considered positive news, as they indicate improvements in health care, air pollution control measures and access to treatment,” said Farshad Farzadfar, a senior author of the study.

"However, the increase in disability-adjusted life years suggests that although fewer people were dying from cardiovascular disease, more people were living with disability," Farzadfar said.

The researchers also found that between 1990 and 2019, age-standardised CVD death and disability attributed to outdoor PM pollution rose by 8.1 per cent, while age-standardised cardiovascular death and disability attributed to household PM pollution, which is produced by solid cooking fuels such as coal, charcoal, crop residue, dung and wood, fell by 65.4 per cent.

“The reason for the decrease in the burden of household air pollution from solid fuels might be better access and use of cleaner fuels, such as refined biomass, ethanol, liquefied petroleum gas, solar and electricity,” Farzadfar said.

"Moreover, structural changes, such as improved cookstoves and built-in stoves, chimney hoods and better ventilation, might be effective in reducing pollution exposure to solid fuels,” Farzadfar added.

The authors acknowledged several limitations of the study. Because the assessment of exposure to particulate matter pollution in the study is based on regional estimates, it may not accurately reflect individual exposure.

In addition, results from this analysis of the association between particulate matter pollution and cardiovascular outcomes may not be generalizable to other health conditions or other pollutants, they added.