‘Like unfiltered cigarettes’: Why is wildfire smoke so dangerous for the lungs?

Wildfire smoke drifting down from Canada has left parts of the U.S. coughing under a haze of orange skies for much of June, and it’s raising awareness among the public about air quality linked to climate change.

Even those people limiting their outside exposure and in relative sound health are still sucking in potentially unhealthy levels of particulate matter. For the elderly, pregnant people, young children and those with already compromised health, this exposure is very risky.

A…