Code Orange, Explained: When Mercury Rises, So Does Smog

0
Share the News


During yesterday's Code Orange AQI day, Baltimore's smog/ozone levels shot past the moderate levels between 4 p.m. to 7 p.m. Credit: cleanairpartners.net
During yesterday’s Code Orange AQI day, Baltimore’s smog/ozone levels shot past the moderate levels between 4 p.m. to 7 p.m. Credit: cleanairpartners.net

“Tomorrow’s going to be a Code Orange air quality day.” Sure enough, September 2, 2015 was a typical Baltimore muggy scorcher of a day and our air quality was crappy. Understanding local air quality alerts will help protect your family. Even if your friends and family aren’t impacted by air pollution, collectively reducing pollution on ‘Code Orange’ days contributes to cleaner air for your neighbors.

The Air Quality Index (AQI) is nationwide color-coded alert system issued by the Environmental Protection Agency (EPA). We can thank the 1970 Clean Air Act and the EPA for regulating “acceptable” levels of five air pollutants. These levels are converted into the green, yellow, orange, red and dark red color codes.

The Air Quality Index converts federally-regulated levels of air pollutants into understandable good, ok, not so good, bad, awful levels.
AQI converts federally-regulated air pollutants into understandable good, ok, not good, bad, awful levels.

What’s interesting is that green and yellow days are considered within okay limits for sensitive groups, but also that the area met its federal pollution limits. Orange, red and dark red days aren’t healthy for the 1.5 million in the sensitive group in our DC-Baltimore metro. Code Orange and Red days also mean that our area’s air quality was out of compliance with the Clean Air Act pollution limits.

The pollutant most people recognize is ground-level ozone. The sky-high ozone in our atmosphere keeps our planet habitable. But ground-level ozone is a nasty gas, a poison really, that’s formed when the sun bakes nitrogen oxide and volatile organic compounds. Cars spew about 30 to 40 percent of these chemicals, with power plants and industry contributing the rest.

The ozone chart above tells yesterday’s story; between 4 p.m. to 7 p.m. was not the ideal time for anyone to be jogging. Baltimore’s ground-level ozone shot past federally-regulated healthy levels because our high was 91 degrees, and it wasn’t breezy. You bet more people visited the emergency room, especially since 20 percent of Baltimore’s kids suffer asthma (that’s twice the national average).

Interestingly, today is another scorcher. Today is also a BGE Energy Savings Day where BGE customers get paid to reduce electricity usage. PeakRewards customers will have their air conditioners and/or hot water heaters cycled down between 1 p.m. to 7 p.m. Collectively reducing electricity usage not only ensures the grid doesn’t get overloaded, but also means less power plant pollution, less nitrogen oxide, and less smog or ground level ozone. That will help us all breath easier.

In 2008 ozone levels dropped to 75 p.p.b. This chart translates the federal ozone level to the AQI. Code Orange and above means Maryland's ozone past federal limits. Credit: cleanairpartners.net
In 2008 ozone levels dropped to 75 p.p.b. This chart translates the federal ozone level to the AQI. Code Orange and above means Maryland’s ozone exceeded federal limits. EPA proposed ozone drops to 65 to 70 p.p.b.  Credit: cleanairpartners.net

Laurel Peltier
Follow me

Laurel Peltier

Laurel writes the environmental GreenLaurel column every other Thursday in the Baltimore Fishbowl. A graduate of UVA's MBA program, she spends her time with her family and making "all things green" interesting.
Laurel Peltier
Follow me


Share the News