Health officials are concerned about the long-term health ramifications from the smoke and air pollution being generated by wildfires throughout Australia.

The unprecedented fires burning across Australia offer the most recent example as they blanket major cities with dangerous air pollution. Smoke from those fires, which started burning in September, by this week had spread across more than 7.7 million square miles and drifted across the Pacific Ocean to reach South America.

Compounding the danger, experts and firefighters say, is the proliferation of construction materials and household items made from petroleum-based plastics, ranging from plumbing pipes to exterior siding. Those burn hotter and generate smoke more toxic than wood does, exposing people to numerous hazardous chemicals.

Researchers and health officials are confident more people will get sick and many will die as regions such as the US West see bigger, more intense wildfires.

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