Emergency Health Risk Communication During the 2007 San Diego Wildfires: Comprehension, Compliance, and Recall

Abstract

In October 2007, wildfires burned nearly 300,000 acres in San Diego County, California. Emergency risk communication messages were broadcast to reduce community exposure to air pollution caused by the fires. The objective of this investigation was to determine residents’ exposure to, understanding of, and compliance with these messages. From March to June 2008, the authors surveyed San Diego County residents using a 40-question instrument and random digit dialing. The 1,802 respondents sampled were predominantly 35–64 years old (65.9%), White (65.5%), and educated past high school (79.0%). Most (82.5%) lived more than 1 mile away from the fires, although many were exposed to smoky air for 5–7 days (60.7%) inside and outside their homes. Most persons surveyed reported hearing fire-related health messages (87.9%) and nearly all (97.9%) understood the messages they heard. Respondents complied with most to all of the nontechnical health messages, including staying inside the home (58.7%), avoiding outdoor exercise (88.4%), keeping windows and doors closed (75.8%), and wetting ash before cleanup (75.6%). In contrast, few (<5%) recalled hearing technical messages to place air conditioners on recirculate, use High-Efficiency Particulate Air filters, or use N-95 respirators during ash cleanup, and less than 10% of all respondents followed these specific recommendations. The authors found that nontechnical message recall, understanding, and compliance were high during the wildfires, and reported recall and compliance with technical messages were much lower. Future disaster health communication should further explore barriers to recall and compliance with technical recommendations.

Acknowledgments

The authors thank Cathy Cirina and Jeff Toor at the San Diego State Social Science and Research Laboratory for their excellent work in administering the telephone survey; Jacqueline Polder, Centers for Disease Control and Prevention Quarantine Officer at the Houston Airport, for providing pandemic influenza expertise; and Gabrielle Benenson and Clive Brown, who provided recommendations on the survey design.

Costs for the random digit dial survey and personnel were supported by a grant by the Centers for Disease Control and Prevention.

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention, U.S. Department of Health and Human Services.

Notes

†2005–2007 American Community Survey 3-Year Estimates.

§Source: 2008 San Diego Association of Governments.

*For census data, English if only spoke English or spoke another language and English “very well,” Spanish if spoke Spanish and English “well” or less, and Other if spoke any other language and English “well” or less.

**For census data, household income reported in real 2007 dollars adjusted for inflation for those 16 years or older.

*Without prompting.

**Persons were asked the degree of message compliance among all messages heard, saw, understood, and applicable to them during the week of the fires.

*Signed rank (Wilcoxon or Kruskal-Wallis).

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