In response, public health officials issued air quality advisories and suspended some government operations. New York City launched emergency operations Wednesday offering free KN95 masks and opening shelter locations. Due to deteriorating air quality, Philadelphia city officials on Friday suspended trash collection and closed public swimming pools.
High levels of airborne particles can worsen health problems for those considered sensitive, including children, pregnant women, the elderly and people with asthma or heart disease. Higher levels are dangerous for anyone who breathes it, and people should be especially careful around wildfire smoke, said Suzanne Paulson, director of the UCLA Clean Air Center.
“No particles are breathable, but wildfire particles appear to be more toxic than regular urban particles themselves,” Paulson told NBC News. “Whatever the color (AQI) is, note that it is the next color if there is a lot of wildfire smoke around.”
Wildfire smoke is made up of microscopic particulate matter, ash and trace elements that combine with water vapor to create a haze effect. Fine particulate matter, called PM2.5, is the most dangerous because when deeply inhaled, it penetrates the lungs and even enters the bloodstream. PM2.5 particles are smaller than a grain of sand and 30 times smaller than the width of a strand of hair, says Serap Erdal, a professor at the University of Illinois at Chicago and project leader for Open Air Chicago, a citywide network of air sensors.
The best way to protect yourself, experts say, is to stay home and avoid outdoor physical activity in areas with exceptionally high air quality. Keeping children indoors limits their exposure to pollutants and can reduce their activity levels, which reduces the number of particles they inhale, Paulson said.
Using an air purifier or setting your air conditioner to recirculate can also help recycle the air and clear it of toxins, Erdahl says. “Just because we’re indoors doesn’t mean we’re not breathing outside air.”
When outdoors, wearing high quality particulate masks such as N95 or KN95 can reduce exposure. A regular surgical mask may provide a small barrier, but will not filter out small particles, Erdahl said.
“Although healthy people can recover quickly from wildfire smoke, many people may experience short-, medium- and long-term effects,” Erdahl said. “It’s important that people take steps to protect themselves.”