At least five people have died, four firefighters have been injured and more than 1,000 homes have been destroyed as major wildfires, fuelled by strong winds, continue to ravage the Los Angeles area in the United States,

Southern California — with sprawling cities, clogged freeways and heavy industry — is already notorious for some of the worst air quality in the nation. This week's wildfires are putting millions of people at risk for immediate health problems and longer term issues.