Issue 2: Air Pollution and Health
Los Angeles. Image: Pacific Standard Magazine
Our second newsletter by the University of California Center for Climate, Health, and Equity tackles the health impacts of air pollution.

Since 1990, implementation of the Clean Air Act has led to a 50% decline in pollutant emissions (just one of many examples of regulations protecting human health). But air pollution is back on the rise, largely due to increased emissions and wildfires, and especially in California, which consistently ranks as the most polluted state in the country. Climate change also plays a role, given its synergistic relationship with air pollution. Climate change limits the removal of pollutants (e.g. by reducing rainfall in some regions) and also increases their production (e.g. by increasing forest fire frequency and causing build up of ground-level ozone). And pollutants can affect the climate; for example, soot absorbs heat and increases local temperatures. But good news: the two are also interlinked when it comes to solutions: climate solutions that reduce CO2 often reduce the emissions of other toxic pollutants as well.

Here's a basic overview of the five pollutants most relevant for human health:
The EPA uses its Air Quality Index (AQI) to report air quality. A separate index is calculated for each of the five pollutants above. The highest number becomes the area's AQI for the day, and can be used to guide decision-making about exposure risk. One easy-to-use resource for evaluating local AQI is PurpleAir.

Though respiratory disease is most commonly associated with air pollution exposure, recent studies have unearthed a much wider range of health impacts:
Life and Breath: Clinician's Corner

At the structural level, clinicians can be instrumental in advocating for measures that reduce the air pollution their patients are exposed to (bike-friendly urban planning, for instance). In the meantime, however, clinicians should help guide their patients in strategies to mitigate and avoid the negative health effects of air pollution.

A literature review in the European Respiratory Journal summarized the following evidence-based recommendations for minimizing the health effects of air pollution.
  • Use close fitting N95 masks or charcoal-containing masks when exposure to air pollution is unavoidable. Cloth masks are not effective against particulate matter pollution.
  • Choose travel routes that avoid busy roads and intersections with high amounts of traffic-related emissions, especially if you have existing cardiopulmonary conditions.
  • Moderate outdoor physical activity when air pollution levels are high.
  • Monitor air pollution levels in your area and plan activities accordingly, particularly if you have existing cardiopulmonary conditions.
  • Use portable indoor HEPA air cleaners if living in an area with a high air pollution burden.
Systemic Air Pollution Inequity

Despite overall decreases in PM2.5 pollution over the last few decades, systemic racial and socioeconomic disparities in exposure have persisted. One study demonstrated that across nearly all major emission categories and geographic areas, people of color have higher rates of exposure to PM2.5. Like the disparities in heat exposure discussed in our last issue, these disparities have their roots in the historical practice of redlining. And when you consider differences in exposure relative to differences in consumption, the disparities further enlarge; a PNAS study showed that non-Hispanic whites experience 17% less air pollution exposure than is caused by their consumption, while Blacks and Hispanics bear 56% and 63% excess exposure relative to their consumption. In other words, air pollution is disproportionately driven by white consumption of goods/services and minority groups are disproportionately breathing it in.   
Image: NYTimes

But.... some good news!

The Bay Area Air Quality Management District's (BAAQMD) Board of Directors voted in July to further reduce particulate matter emissions from petroleum refineries, a win for environmental justice for the one million mostly people of color who live near East Bay refineries. Thank you to the local advocates who worked tirelessly for this rule, which is the most stringent regulation of its kind in the nation.
Hot off the Press: What We're Reading

  • By the end of the century, increasing aridity could lead to higher dust levels in the U.S. Southwest, increasing dust-attributable premature mortality and hospitalizations by 220% at a cost of an additional $47 billion per year, according to this GeoHealth study.
  • A recent study in Atmósfera found that high exposure to PM2.5 and PM10 pollution was associated with increases in pulmonary TB incidence in a Mexican border region; for each 10 µg/m3 increase in PM, incidence of TB rose by 3-5%.
  • PM2.5 and NO2 pollution also seem to be correlated with COVID-19 incidence and mortality, according to this small systematic review in Environmental Research.
  • Another systematic review in JAMA Network Open suggests that there are significant associations between PM2.5 or ozone exposure and poor birth outcomes, such low birth weight and preterm birth – across the entire U.S., but particularly among Black mothers.

Breathe In Some New Knowledge

This newsletter was created by Karly Hampshire, Sigal Maya, Lawrence Huang, Sophie Genigeorgis, and Simona Martin, and edited by Sheri Weiser, Arianne Teherani, Jennifer Zakaras, and Naomi Beyeler, on behalf of the UC Center for Climate, Health, and Equity.