Canadian wildfires waft more smoke into Louisville. Here's what to know about air quality

The Louisville Metro Air Pollution Control District has forecast air quality to be "unhealthy for all groups Wednesday," according to a tweet.

Air pollution control and the Indiana Department of Environmental Management have issued a code red air quality alert until midnight for Louisville and surrounding areas in Central Kentucky and Southern Indiana. Anyone could experience unhealthy side effects from the air quality, and sensitive groups — those who have trouble breathing, for example — may experience more serious outcomes, the weather service said.

More smoke put off from a string of Canadian wildfires is slated to move into the region, causing the air quality index to spike, according to a tweet from air control. Smoke has been wafting into the U.S. for several weeks, making air in Louisville and nearby cities such as Chicago hazy and potentially unsafe.

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Canada has been battling more than 400 wildfires that have displaced at least 20,000 people, with officials calling it the "nation’s worst wildfire season ever," according to the Associated Press. "It started early on drier-than-usual ground and accelerated very quickly, exhausting firefighting resources across the country, fire and environmental officials said."

Louisville's air quality index measured between around 150 and reached above 180 as of Wednesday morning, according to an air quality map.

Unhealthy levels for air quality start around 101 for people in sensitive groups, the site said. Levels nearing 200 start to become unhealthy for the general population.

A heat advisory has also been issued from 2 p.m. Thursday to 9 p.m. Friday for much of Western Kentucky, the weather service said. Heat index values could reach up to 105 with hot temps and humidity that could cause heat illness.

What do I need to know about unhealthy air quality conditions?

Dr. Steven Patton, a family medical and urgent care practitioner, said air quality right now is "frightening," but there are things folks can do to mitigate the effects of air pollution and some symptoms to watch out for.

Patton favored staying indoors on days when air quality is nearing unsafe levels, but if you need to go out, he suggests wearing a mask.

Even if you're staying indoors, small particulates, dust and pollen brought from outside can disturb the air quality. Patton recommended changing air filters, vacuuming carpets and changing linens regularly.

Chronic cough that gets worse at night, sinus congestion, chest tightness and ear pain are all symptoms that Patton said could be exacerbated lung-related illnesses like asthma due to exposure to poor air quality, though there is no one-size approach to which symptoms are related. He suggested regularly taking medications for allergies or asthma.

Long-term effects of exposure to poor air quality can lead to an increased risk of heart and lung-related illnesses, Patton said.

What is an air quality alert?

According to Columbia University, the EPA created the air quality index, or AQI, "to monitor and report on air quality each day and let people know about its possible health impacts."

Over 1,000 locations in the United States monitor and record the air for four significant pollutants: ground-level ozone, particulate matter, carbon monoxide and sulfur dioxide. An air quality index level of 100 is considered safe. An AQI under 100 is good or acceptable, and an AQI over 100 is cause for concern, especially for vulnerable groups. Levels over 300 indicate hazardous conditions.

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The Associated Press and Cincinnati Enquirer contributed. Contact reporter Rae Johnson at RNJohnson@gannett.com. Follow them on Twitter at @RaeJ_33

This article originally appeared on Louisville Courier Journal: Air Quality Index: Canadian wildfires bring more smoke to Louisville