PM2.5 suspended dust particles from coal combustion may be more harmful than those from other emission sources. An American study showed that in the years 1999-2020 they contributed to 460,000 deaths, and the increase in their level in the air resulted in an increase in mortality in polluted regions. Scientists reassure us that “cleaning” energy can reduce this problem.
Various air pollutants have different effects on our health – contrary to appearances, it depends not only on the size of the particles. According to a study published in the scientific journal “Science”, also a source smog may affect how it affects the body.
Hundreds of thousands of deaths
In their analysis, American researchers used emissions data from 480 coal-fired power plants in the United States from 1999 to 2020. Based on them, they developed a model of the movement of sulfur dioxide released from coal in the atmosphere and where it fell as PM2.5. The results were compared to medical data representing the health of Americans aged 65 and over. On this basis, it was determined to what extent people living in a given area were exposed to inhalation of PM2.5 from coal dust and how it affected their health.
They found that in 1999, the average level of PM2.5 from coal dust in the United States was 2.34 micrograms per cubic meter of air. This level dropped significantly by 2020 (0.07 µg/m3). After excluding additional factors, the researchers calculated that a 1 µg/m3 increase in the average annual level of PM2.5 from coal was associated with an increase in all-cause mortality of 1.12 percent – 2.1 times greater than for PM2.5 from any another source. A total of 460,000 deaths could be attributed to carbon-based PM2.5, and in the years 1999-2007 it contributed to an average of over 43,000 deaths per year. After 2007, this number decreased dramatically, reaching 1,600 in 2020.
“In addition to showing how harmful carbon pollution has been, we also report good news,” said Lucas Henneman of George Mason University, lead author of the study. – Coal deaths peaked in 1999 but fell by about 95 percent by 2020 as coal plants installed scrubbers or closed.
The researchers explained that many previous studies of mortality associated with coal-fired power plant operations assumed that PM2.5 from coal had the same toxicity as PM2.5 from other sources.
– PM2.5 from coal was treated as if it was just another air pollutant. But it is much more harmful than we thought, and its mortality has been seriously underestimated, Henneman added.
As the authors reported, the study perfectly shows that if we continue to strive to “purify” energy, we can influence our health and life expectancy. This awareness is particularly important in a world where coal energy is still part of energy portfolios in many places around the world, and global use of coal for electricity generation is even expected to increase.
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