California Faces Health Hazard From Extreme Heat and Wildfires Combined

Californians are at a greater risk when extreme heat and wildfire smoke meet, a study has found.

The extreme heat and wildfires during summer in California have become a combined health hazard for people living in the state and can even increase the risk of cardiorespiratory problems.

The risk of hospitalizations with cardiorespiratory problems increased dramatically when smoke and extreme heat were both considered, the study published in Science Advances found. This was based on satellite and environmental monitoring data assessed between 2006 and 2019.

California has the most wildfires of any state, and they have only been increasing with an increase in intense conditions.

Between 1992 and 2020, almost all of California’s wildfires were caused by human activities, according to data from the U.S. Forest Service. An increase in extreme temperatures is also contributing to the amount of wildfires igniting in the summer months. The increasing temperatures, which is largely down to climate change, has caused prolonged drought conditions in the state in recent years.

Throughout the study, researchers found risks of smoke and heat were higher in less wealthy and more crowded areas, according to lead author Chen Chen, a Ph.D. candidate in computer science from the University of California, San Diego. The effects of smoke and heat were also more pronounced in areas with a higher population of racial and ethnic minority people.

The finding “highlights the need to incorporate compound hazards and environmental justice considerations into evidence-based policy development to protect populations from increasingly prevalent compound hazards,” the authors wrote in the study.

The researchers looked at the number of cardiorespiratory hospitalizations across 995 areas that experienced at least one day of extremely high temperatures, one day of increased exposure to wildfire smoke and then one day where both of these things were present. When both smoke and heat was recorded, hospitalizations increased.

Wildfire smoke can cause negative effects on the body when it is around for a prolonged period of time. It can irritate the nose, throat and eyes. Those with existing respiratory issues like asthma may also experience worsening symptoms.

“Our finding that hospitalizations on days with concurrent extreme heat and wildfire smoke events exceeded the combine hospitalizations from days with either hazard alone motivates the consideration of compound climate hazards in public health planning,” the authors wrote in the study.

Although governments are becoming more aware of the combined effect of hot temperatures and wildlife smoke, the authors note that a better understanding of the adverse health effects will improve initiatives that could be implemented to improve public health.