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In this country, a new study estimates that inhaling wildfire smoke contributed to thousands of additional COVID-19 cases, including hundreds of deaths in Western states. From our member station KQED in San Francisco, Farida Jhabvala Romero reports.
FARIDA JHABVALA ROMERO, BYLINE: On September 9, 2020, more than two dozen wildfires were burning in California. In the San Francisco Bay Area, the air turned so hazy, people couldn't see the sun.
SUSANA VILLANUEVA: It just felt scary.
ROMERO: Susana Villanueva shows me a photo of her sister, Maribel, at the home where they lived together in Oakland.
VILLANUEVA: I think this was for my mom's birthday right here. And she is right here.
ROMERO: Susana remembers her sister started coughing during those smoky days. But Maribel kept going to work at a daycare. She walked and took the bus, wearing only a cloth mask.
VILLANUEVA: She said, you know, I think it was the smoke that really affected me. And that's why I have this cough.
ROMERO: Soon, Maribel was diagnosed with COVID-19. Over two weeks, her symptoms worsened. Then in early October, she died. She was 46 and a single mom. She left behind a 10-year-old son, David.
VILLANUEVA: And definitely, there's times where, you know, I mean, if I miss my sister, I'm pretty sure he misses his mom.
ROMERO: Alameda County, Calif., where Maribel Villanueva lived, saw one of the biggest spikes in COVID-19 deaths linked to wildfire smoke last year, according to a new study published in the journal Science Advances. Researchers found that higher levels of air pollution from wildfires amplified COVID-19 cases and deaths in scores of counties in Oregon, Washington and especially California. Francesca Dominici is a professor at the Harvard School of Public Health and the study's senior author.
FRANCESCA DOMINICI: This study, for the first time, I think, will make the clear link between climate change and the pandemic.
ROMERO: Drought and heat are major drivers of mega fires, like some burning now in Oregon and California that are spewing toxic particles to places as far away as North Dakota. Dominici says wildfire smoke can hurt the immune system and make people more prone to lung infections, including COVID-19.
DOMINICI: Wildfire exposure and COVID are actually really dangerous combination together.
ROMERO: People can protect themselves from the smoke by staying indoors with windows shut. But that's not an option for people who work outside their home, especially in low-income communities of color. John Balmes is a pulmonologist at the University of California, San Francisco.
JOHN BALMES: So it's an environmental justice issue that, you know, our society should be dealing with.
ROMERO: He thinks local governments should do more to provide N95 masks and air filters to low-income families and essential workers. Susana Villanueva says her sister, Maribel, didn't have an air filter at home or an N95. Susana took custody of Maribel's son after her death. Now she tells him...
VILLANUEVA: I will never be able to replace your mom. But I'm here. We love you. I want you to know that we care for you. So just taking it one day at a time.
ROMERO: Susana says they'll miss Maribel forever.
For NPR News, I'm Farida Jhabvala Romero in Oakland. Transcript provided by NPR, Copyright NPR.