Congressional investigators say the use of a regulatory loophole to erase smoke pollution from the official record is on the rise.

In 2010, the number of Californians living in areas exposed to at least one day of 100 micrograms of PM2.5 barely crossed 200,000. A decade later, that number increased to 4.5 million.

NPR’s California Newsroom is collaborating with MuckRock and Columbia University’s Brown Institute for Media Innovation to investigate how wildfires affect air quality across the country. If the smoke from wildfires is damaging your health, disrupting your daily routine or forcing you to consider moving elsewhere, we want to hear from you.