Heat and ozone are associated with an increased number of respiratory hospitalizations in low-income neighborhoods, a study finds. Extreme heat events and high ozone days are likely to increase in frequency due to climate change. However, there is no early warning system that jointly considers both heat and ozone, and how the combined health effects of heat and ozone vary across fine spatial scales or are influenced by sociodemographic factors remains unclear. Lara Schwarz and colleagues analyzed spatial variation in the additive effects of extreme heat events and ozone on 817,354 respiratory hospitalizations in California from 2004 to 2013 in the May to September period. The combined effects of heat events and ozone on respiratory hospitalizations were not significant overall when averaged across the entire state but exhibited substantial spatial variation on a local scale. Stronger joint effects occurred in zip codes with a higher percentage of non-White individuals and residents lacking employment or health insurance. By contrast, weaker joint effects occurred in high-income zip codes with a larger proportion of commuters who walk or ride a bike. According to the authors, the results could be used to establish appropriate temperature and ozone thresholds at the local level to better protect population health.
Article #2020-23078: "Spatial variation in the joint effect of extreme heat events and ozone on respiratory hospitalizations in California" by Lara Schwarz, Kristen Hansen, et al.
MEDIA CONTACT: Lara Schwarz, University of California, San Diego, CA; email: lnschwar@health.ucsd.edu
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Journal
Proceedings of the National Academy of Sciences