California fashions itself as a place of sandy beaches and sunny skies, where we take our greens juiced and our cars electric.
But dual crises — the pandemic and the changing climate — have challenged this version of life in the Golden State. To date, California, the country’s most populous state, has racked up the most coronavirus infections in the U.S., while air monitoring data shows that Californians also breathe the most polluted air in the nation.
Now a growing body of research suggests this may be no coincidence. This week, researchers from UCSF and the Public Health Institute published a study that found that Californians exposed to PM 2.5, a fine particulate matter that spews from tailpipes and industrial sources common in cities, had a much greater risk of infection and death from COVID-19.
The study, sponsored by the California Air Resources Board and published in the journal Environmental Advances, was one of the first to home in on neighborhood-level health and air monitoring data to explore the effect of long-term pollution exposure on COVID infections and mortality in the state.
The goal, said John Balmes, professor of medicine at UCSF and co-author of the report, was to improve upon previous research by applying a finer lens on population data and air quality in different air basins.
The results are grim: Residents exposed to long-term elevated levels of air pollution were 20% more likely to contract COVID-19 and over 50% more likely to die because of it. The study estimates that if air quality impacts were improved, over 4,000 deaths could have been prevented within the timeframe studied, which was between February 2020 and February 2021.
To put that another way, “We found a factor that could have prevented 9% of COVID deaths,” said Paul English, director of Tracking California at the Public Health Institute and co-author of the study. “That’s a lot.”
These findings come as yet another surge of the coronavirus washes over the Bay Area and mushrooming plumes of smoke from the first major wildfires of the summer billow in the distance, prompting the Bay Area’s air district to extend an air quality advisory late into the week.
A key component of wildfire smoke: PM 2.5
Though the UCSF study didn’t address the short-term impacts on respiratory health from wildfire smoke, other research has found that both short- and long-term exposure to air pollution increases not only the rate of transmission but also the severity of the infection and mortality rates associated with COVID-19.
Beyond the short-term impacts of wildfire smoke, the most harmful concentrations of PM 2.5 were found in the San Joaquin and South Coast air basins, the latter including Los Angeles.
The study also plainly stated that health and environmental burdens fall most heavily on disadvantaged communities — including those in the Bay Area. Of the over 3 million infections and 50,000 deaths included in the UCSF analysis, the risk of infection and mortality were highest in neighborhoods with the greatest percentage of Hispanic and Black populations.
It’s a fact that reflects a national trend: In the United States, people of color are over three times more likely to live in areas with high concentrations of air pollution compared with white populations, the American Lung Association found.
“The pandemic really laid bare the disparities that have existed and that have been there for a long time,” said Balmes.
Although Balmes said that the state’s air quality has been improving in recent years, thanks to stricter regulations, “There’s still a discrepancy between more affluent white communities and lower (income) communities of color,” said Balmes, who sits on CARB’s board.
But it’s not just COVID-19 that public health experts like Balmes are worried about. Exposure to ambient air pollution has long been known to cause health problems, including respiratory and cardiovascular diseases, adverse reproductive outcomes, neurological disease and premature death, noted Balmes.
While there is still more to learn, particularly around the way wildfires will impact the severity and spread of disease, this study is a clarion call for the state to rapidly reduce its air pollution, said Balmes, a measure that would benefit the health of residents and the planet, too.