Massive plumes of Canadian wildfire smoke are set to pour over the border into the United States, bringing dangerous air quality to more than 100 million people in the Midwest and Northeast.

Smoke Forecast

A first round of smoke is already floating over a large area from Chicago to Boston. This smoke has largely stayed higher up in the atmosphere, which means it hasn’t precipitously lowered air quality or posed a significant health risk.

However, a weather pattern change in coming days will cause lingering smoke and additional plumes to sink to the surface Wednesday and Thursday, bringing unhealthy air quality from the Upper Midwest to New England.

Wildfire smoke contains dangerous, tiny pollutants called PM2.5 that can travel deep into the lungs or enter the bloodstream when inhaled. The minuscule particles can lead to breathing problems like bronchitis and cause inflammation that aggravates diabetes, heart disease, and other health conditions.

Health Risks

People with lung or heart disease, children, and older adults are especially at risk for smoke-related illness. The National Weather Service advises people to avoid smoke by limiting outdoor activities and keeping windows closed overnight.

Much of Michigan, Minnesota, and Wisconsin are under air quality alerts due to smoke over the next few days, and the National Weather Service has warned that smoke could become an air quality concern in Chicago later this week.

Original reporting: El Paso News (HLL/CB) — read the source article.