Chad MurphyColumbus Dispatch
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- The air quality in Central Ohio and Southwest Ohio is bad today because of the heat wave.
- Hot temperatures encourage the formation of ground level ozone, a gas that can irritate people's lungs and is the main component of smog.
- Wildfires are also a factor, as they spew carbon monoxide and particulate pollution into the atmosphere.
As Ohio continues to swelter under a heat wave this week, the extreme temperatures and high humidity are also making it hard for some to breathe.
Several Central Ohio and Southwest Ohio counties are under an air quality alert today. The National Weather Service says ground-level ozone may exceed healthy levels today, carpool and otherwise limit use of gas-powered equipment.
So why is the air quality so bad lately? Here's what to know.
Why is the air quality so bad today? Blame the heat wave
Hot temperatures encourage the formation of ground-level ozone, a gas that can irritate people's lungs and is the main component of smog, NPR reports.
Extreme heat also encourages droughts, NPR reports, which can make big dust storms more likely, hurting the air quality.
What is heat index? How hot does it really feel outside? Use this chart to find out
Wildfires are a factor, too
Droughts also make forest fires more likely. Those fires spew carbon monoxide and particulate pollution into the atmosphere, according to the University Corporation for Atmospheric Research, which can travel thousands of miles and hurt air quality.
Currently, the interactive fire and smoke map at AirNow.gov, which monitors air quality in the United States, shows wildfire smoke drifting over the state.
Wildfires burning in Canada, New Mexico
Wildfires have burned thousands of acres in New Mexico this week, forcing residents of the village of Ruidoso, about 200 miles south of Albuquerque, and surrounding areas to evacuate.
Canadian wildfires are currently burning in Yukon, Alberta, British Columbia, Quebec and Newfoundland and Labrador, according to the Canadian Interagency Forest Fire Centre.
What's the air quality index for Columbus, Ohio?
On Thursday morning, AirNow.gov was showing moderate air quality in the Columbus area, with a value of 74 out of 500. Fine particulate matter, or PM2.5, is the primary pollutant. But the site forecasted that to worsen, becoming "unhealthy for sensitive groups," meaning people with heart or lung disease, older adults, children and teenagers, pregnant people, minority populations, and outdoor workers.
AQI in Cincinnati
Likewise for Cincinnati, the air quality Thursday morning is moderate with a value of 68, but is expected to become "unhealthy for sensitive groups" later today.
Air quality index for Akron, Ohio
In the Akron area, the air quality index is moderate with a value of 83, and AirNow.gov is forecasting it to remain moderate through the weekend.
For moderate air quality, people who are unusually sensitiveto particle pollution should consider reducing their activity level or shortening the amount of time they are active outdoors.
How is an air quality alert issued?
According to the Southwest Ohio Air Quality Agency, if weather data and forecast information show that ozone or particulate matter may meet or exceed an air quality index of 101, an alert is issued.
What is the air quality index?
According to AirNow.gov, the air quality index is a measure running from 0 to 500, indicating how much air pollution is present. The higher the number, the greater the air pollution.
It's six color-coded levels are:
- Green: Good air quality, values from 0 to 50. Pollution poses little to no risk.
- Yellow: Moderate air quality, values from 51 to 100. Some risk to people unusually sensitive to pollution.
- Orange: Unhealthy for sensitive groups, values from 101 to 150. Members of sensitive groups may experience health effects. The general public likely won't.
- Red: Unhealthy, values from 151 to 200. The general public may experience health effects. It may be more serious for sensitive groups.
- Purple: Very unhealthy, values from 201 to 300. At this stage there is a health alert as the risk is increased for everyone.
- Maroon: Hazardous, values of 301 and above. This is a health warning for emergency conditions, as everyone is more likely to be affected.
What is ground-level ozone?
Ozone is a gas made up of three oxygen atoms. In the upper atmosphere, ozone is good, protecting the Earth from the sun's ultraviolet rays. But at ground level, ozone is the main ingredient of smog and a harmful pollutant,according to the U.S. Environmental Protection Agency.
Ozone forms at ground level when pollutants emitted by cars, power plants, refineries and chemical plants, among others, chemically react in the presence of sunlight. Ozone is most likely to reach unhealthy levels on hot, sunny days in urban environments, according to the EPA, and can be carried by wind, spreading the pollution to rural areas.
What is fine particulate matter?
Fine particulate matter consists of particles that areless than 2.5 micronsin diameter. As a comparison, the average human hair is 50 to 70 microns thick. Breathing unhealthy levels of PM2.5 can increase the risk of heart disease, asthma and low birth weight,according to the New York State Department of Health.
According to the EPA, particulate matter can come from any number of sources. Sources include power plants, automobiles, construction sites or wildfires such as the ones burning in Canada.
