Extreme Heat, Air Pollution Tied to Higher Mortality Risk

WEDNESDAY, July 13, 2022 (HealthDay News) -- Short-term exposures to extreme heat and air pollution are individually associated with an increased risk for mortality, with an even greater impact seen with coexposure, according to a study published online June 21 in the American Journal of Respiratory and Critical Care Medicine.

Md Mostafijur Rahman, Ph.D., from the University of Southern California in Los Angeles, and colleagues examined associations for acute coexposure to extreme heat and ambient fine particulate matter (PM₂.₅) with all-cause, cardiovascular, and respiratory mortality (2014 to 2019).

The researchers found that all-cause mortality risk increased 6.1 percent on extreme maximum temperature-only days and 5 percent on extreme PM₂.₅-only days versus nonextreme days. On days with exposure to both extreme maximum temperature and PM₂.₅, risk increased 21 percent. On extreme coexposure days, the increased risks for cardiovascular and respiratory mortality were 29.9 and 38 percent, respectively, which were more than the sum of individual effects of extreme temperature and PM₂.₅ only. Coexposure to extreme PM₂.₅ and minimum temperature revealed a similar pattern. For individuals older than 75 years, the effect estimates were larger.

"Understanding the risks associated with these exposures is really important, because we know that they will increase with climate change in many different parts of the United States and the world," a coauthor said in a statement.

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