Emergency Department Visits During the Fall 2019 Public Safety Power Shutoff Events in California

To prevent power lines from igniting wildfires, utility companies in California are authorized to conduct Public Safety Power Shutoffs (PSPS), de-energizing, or shutting off power to equipment during periods of high wildfire risk. This study assessed the association between PSPS and emergency department visits.

The study quantified the extent to which counties in California experienced PSPS each day between September 15 and November 30, 2019. Linear mixed models were used to estimate the rate of emergency department encounters per 100,000 county residents based on quartiles of PSPS exposure, compared to no PSPS exposure at the county-day level. Analyses examined all emergency department encounters as well as age- and diagnosis-specific visits.

There was an increase of 15 emergency department visits per 100,000 persons aged 65 years and older on days with the highest levels of PSPS exposure compared to days without PSPS. The highest level of PSPS exposure was associated with increased rates of emergency department visits for respiratory, cardiovascular, injury, and mental or behavioral diagnoses.

Despite advanced notification, PSPS events are associated with negative health consequences. Older adults are particularly vulnerable to the unintended adverse health effects of PSPS and should be prioritized in mitigation efforts.