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"In California, Extreme Heat and Ozone Pollution hit Poor Communities Hardest"

National Geographic interviewed Dr. Miriam Marlier, UCLA Fielding School of Public Health professor of environmental health sciences, about the impact of climate change on human health in California

Tuesday, May 25, 2021

When Juan Flores steps out of his Delano, California home into the midst of a heat wave, “it’s like walking into a wall,” he says. Flores lives in the San Joaquin Valley, one of the places where summer heat regularly creeps well above 100 degrees Fahrenheit.

But it isn’t just the heat that Flores is experiencing. During extreme temperatures, the air can be so thick with ozone and fine particle pollution that breathing becomes a chore. Flores has healthy lungs but still feels a painful pressure in his chest on days like that.

Bad heat and bad air together can cause particularly dangerous conditions for vulnerable communities across California, a new study, published in the Proceedings of the National Academy of Sciences finds. Heat and ozone work in tandem to increase the stress on people’s bodies and increase their risk of hospitalization. In California, according to the study, that increased risk is concentrated in poor, under-resourced, and often non-white zip codes like Flores’s.