INDIANAPOLIS — Depending where you are, you can still feel something in the air.

Partly due to the smoke from Wednesday’s fire at the Walmart distribution center in Plainfield, the Indiana Department of Environmental Management is forecasting higher levels of fine particles, or PM2.5, in the air.

The impact resulted in an Air Quality Action Day (AQAD) and a Knozone Action Day for several counties, including Boone, Hamilton, Hendricks and Marion for Thursday.

IDEM expects conditions to improve overnight and Friday.

“There’s so many things that were in that building, made of different substances, that it throws a lot of different types of products and different chemicals into the air,” said Dr. Nadia Krupp, Riley Hospital for Children.

“It’s not quite the same as just breathing in smoke, say, from wood burning,” she added, “It can be more irritating than that, which is why we’re a little bit more careful in situations, like this, where things like plastic, or chemicals, or batteries or all kinds of other things could be involved in that fire.”

According to AirNow, which tracks the air quality index, conditions for Indianapolis area were listed as “Unhealthy for Sensitive Groups” as of Thursday, March 17th.

According to the EPA’s recommendation, sensitive groups include people with lung or heart disease, older adults, children and teens.

Assistant Professor Sarah Commodore at the School of Public Health (IU-Bloomington) says pregnant women are also included in that category.

“If the mom has this circulating in her blood vessels, it’s going to go right through to the baby,” Commodore said.  “Studies have shown that it can actually decrease the development of organs, like the lung for example.”

EPA recommends sensitive groups limit their time outdoors and avoid strenuous activities.

If subjected to continuous exposure, where air quality is a factor, experts say it can trigger irritation or severe complications.

“Keep an eye out for cough, chest congestion, difficulty breathing. That can pop up between 24 and 48 hours after a significant exposure,” said Krupp. “It tends to get better on its own. It gets worse, and takes longer to get better, if you have underlying medical conditions.”

“If you do have asthma or COPD, or you take any respiratory medications, just make sure that you have some of your rescue medications available because you very well may need them in the next 24 to 48 hours,” she added.

If you’re in a situation where you have to be outdoors, experts say masks can help limit exposure, but only to a certain extent.

“It may help a little bit, but a lot of those particles are so small, they’re even going to go through most cloth masks and other types of face coverings,” said Krupp.

If you do use a mask, Commodore recommends opting for an N95 if you can.

“Those are particularly designed to filter out about 95 percent of any particle that you can breathe in,” Commodore said.