How to protect yourself from wildfire smoke and levels of poor air quality

As smoke from raging wildfires in Canada continues drifting into parts of the United States, it's critical to know how you can protect yourself from potentially dangerous levels of air pollution.

Wildfire smoke contains hazardous pollutants that include toxic gases and particulate matter — solid particles and liquid droplets that are produced when these fires burn through trees, buildings and other materials. While some particulate matter can be easily seen in the form of soot, smoke also carries smaller particles that can infiltrate the human body and affect health.

Regardless of whether you’re outdoors or indoors, experts say smoke pollution could affect your health. Here's what you need to know to stay safe.

Latest news: Smoke from Canadian wildfires is spreading south over much of the Midwest, Ohio Valley, Northeast and Mid-Atlantic, bringing dangerous air pollution to the United States. Follow live updates on the wildfires and the impact on air quality.

Where the wildfire smoke is the worst: Satellite imagery Tuesday evening showed smoke covering the Northeast and extending into the Carolinas. Air quality in New York City was particularly poor, and officials urged at-risk residents to wear high-quality masks outdoors. See photos from New York as smoke blankets the city.

Air Quality Index: The U.S. Air Quality Index is the EPA's index for measuring and reporting air quality. Here's an explanation of what Code Red, Code Purple and more mean and why wildfire smoke is so bad for you, plus how to protect yourself.