Health risks as poor air quality hits the Midwest and northern states

In response, public health officials have issued air quality advisories and suspended some government operations. New York launched emergency operations Wednesday, offering free KN95 masks and opening shelter space. Due to deteriorating air quality, Philadelphia city officials suspended trash pickup and closed public pools Friday.

High levels of particle-laden air can exacerbate health concerns for those considered sensitive, including children, pregnant individuals, older adults and those with asthma or heart conditions. Higher levels are dangerous for any who breathe it, and people should be extra careful with wildfire smoke, said Suzanne Paulson, director of the Center for Clean Air at the University of California, Los Angeles.

“No particles are good to breathe, but wildfire particles seem to be more toxic than regular urban particles themselves,” Paulson told NBC News. “Whatever the [AQI] color is, consider that it’s the next color up if there’s a lot of wildfire smoke.”

Wildfire smoke consists of microscopic particulate matter, ash and trace minerals that, combined with water vapor, create the haze effect. Small particulate matter, called PM2.5, is the most dangerous because it can be deeply inhaled, penetrating the lungs and even entering the bloodstream. PM2.5 particles are smaller than a grain of sand and 30 times smaller than the width of a hair strand, said Serap Erdal, a professor at the University of Illinois, Chicago, and the project leader of Open Air Chicago, a citywide network of air sensors.