Poor air quality was expected across the entire Chicago area Tuesday as an "air quality alert" was issued for all of Northeastern Illinois and Northwest Indiana through midnight.
The alert comes as a dangerously hot temperatures and high heat indices continue and severe weather looms over the region.
"The Illinois Environmental Protection Agency has determined that an Air Pollution Action Day will be declared for the greater Chicago Metropolitan Area," the alert said.
As of 7 a.m., Chicago's AQI measured at 60, which ranked as "moderate," according to IQAir.com. NBC 5 Meteorologist Alicia Roman warned that the air quality was expected to worsen throughout the day.
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"Moderate now, but later today, we will be upgraded to 'unhealthy for some,' which is level two of five," Roman said.
Air quality alerts are issued when widespread ozone or particulate levels are expected to be elevated for a prolonged period, creating issues for sensitive groups.
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In this case, elevated ozone levels are being caused by use of air conditioning units, cars and other sources, with pollutants chemically reacting with the sun and causing unhealthy amounts of ozone in the air, according to the EPA.
Active children and adults, especially those with pulmonary or respiratory illnesses or other preexisting conditions, should limit prolonged outdoor activity, according to officials.
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Area residents are also urged to reduce activities that could increase air pollution, including limiting daytime driving, reducing rapid acceleration and hard braking in vehicles, avoiding use of gas-powered lawn and garden equipment, and delaying using harsh chemicals around the home or your lawn.
