Bolivia has seen the largest number of wildfires since 2010 with at least 3 million hectares (7.5 million acres) burned this year according to Inpe, Brazil's space research agency that monitors fires.

Here's what you should know about air pollution from these blazes

A Southern California wildfire rages virtually unchecked in thick brush on Wednesday after destroying dozens of houses near a highway corridor between Los Angeles and Las Vegas and forcing as many as 80,000 residents to flee their homes, officials said.