Raging wildfires that engulfed Southern California earlier this decade not only destroyed neighborhoods laying in their path, they also caused significant health problems for many who lived outside the fires’ reach.

An analysis of hospital and emergency department admissions directly before, during and after the 2003 Southern California wildfires shows a dramatic increase in treatment for those with asthma, bronchitis and other respiratory disorders. Data points to the importance of educating people with existing respiratory ailments to react quickly to symptom onset and take precautionary measures. Results suggest that those at risk face similar health issues during current Southern California firestorm activity.

Heavy smoke conditions were associated with:

  • 34 percent increase in asthma admissions;
  • 67 percent increase in acute bronchitis admissions;
  • 48 percent increase in chronic obstructive pulmonary disease admissions; and
  • 45 percent increase in pneumonia admissions.

The hardest hit patients were young children and the elderly. Teens with asthma also were affected.

UC Irvine environmental epidemiologist Dr. Ralph Delfino led the study, which analyzed more than 40,000 admissions to Southern California hospitals in a month-and-a-half period surrounding raging wildfires in October 2003 that burned nearly three-quarters of a million acres and destroyed approximately 5,000 buildings.

According to study findings, public health officials need to increase preventive measures – such as advising people to avoid outdoor activities and advocating use of anti-inflammatory medications at the first sign of a wildfire for people who have asthma.

“It’s important to learn from this study that large-scale wildfires can have wide-ranging effects on human health. It will be vital to educate those at risk with existing respiratory conditions to react quickly at the earliest signs of symptoms with preventive interventions,” Delfino said. “This data has broad policy implications, as the health impact of wildfires will probably increase worldwide due to the effects of global warming.”

The study has been presented to the South Coast Air Quality Management District and will appear in the online version of Occupational and Environmental Medicine. To aid their analysis, investigators used sophisticated models including NASA satellite images to link hospital data to daily air-particle concentrations at the ZIP codes of patients’ homes throughout Southern California.

Delfino worked with statisticians, public health officials and environmental health researchers from UCI, UCLA, the California Department of Health Services and the California Office of Environmental Health Hazard Assessment. Hospital admissions data were obtained from the California State Office of Statewide Health Planning and Development.

Delfino studies air pollutants’ effects on respiratory and cardiovascular health and leads one of the nation’s first public health studies on how ultrafine particles in urban air contribute to coronary heart disease in the elderly. In 2005, Delfino won an award from the South Coast Air Quality Management District for his contributions to cleaner air.