“Extreme heat days carried a 6.1 per cent increase in risk of death. On extreme air pollution days, deaths were five per cent more likely. But on days with both extreme heat and air pollution, deaths were 21 per cent more likely. This synergistic effect almost double the impact of the individual exposures combined,” the researchers said.
POLLUTION ; MORTALITY EFFECT
Lead author of the study Mostafijur Rahman of the Keck School of Medicine at USC claimed that the mortality effect of exposure to both extreme temperatures and extreme pollution is greater than the sum of their individual effects.
The researchers claimed that it was first study to use a new approach to look into what happens when extreme heat and air pollution coincide.
Meanwhile, program director in NSF’s Directorate for Engineering Bruce Hamilton opined that the increase in deaths expected to occur as a consequence of the rise of extreme heat and wildfires associated with climate change accentuates how important mitigation and adaptation measures have become.
The researchers analysed deaths in California between 2014 and 2019 ( about 1.5 million) using death certificate data from California’s Department of Public Health. They also obtained data on air temperature and levels of fine particulate matter, tiny particle in the air that is known to cause health problems. They found that overall mortality risk increased 21 per cent on days with both extreme heat and air pollution. The risk of death due to cardiovascular problems increased 29.9 per cent and risk of death due to respiratory problems increased 38 per cent.
They mentioned that older adults faced a higher risk, with a 36.2 per cent increase in mortality risk for those over 75, compared to an 8.5 per cent increase in mortality risk for people 75 age and under when exposed to both extreme heat and pollution.
The U.S. National Science Foundation supported the research.