Bad Air? Red alert in Atlanta!

Today and tomorrow are Ozone Red alert days for the Atlanta area, highlighted in various news reports. We've already had a number of “Yellow” alerts, that warn people with sensitive respiratory conditions not to spend time outside. With the Red alert, everyone is warned to stay inside, and asked to avoid pumping gas until the evening hours, and (ideally) to carpool or avoid driving as much as possible. Being Americans, most of our citizens pay not attention.

So what's going on? Let me tell you what I know.

Fifty years ago we talked about “smog”, a combination of smoke and fog that killed people in London in the '50's. Thanks to all of the research of the 1970's, we learned that ozone (a reactive form of oxygen, or O3) was the culprit. Ozone is made by the interaction of chemicals in the air plus sunlight. Since there's more sunshine in the summer, there's more ozone.

The EPA standard for ozone is 75 parts per billion, or .075 parts per million. This is also the “red zone” level. In truth, lower levels probably have health effects, but because we aren't as sure, we can't claim them. Anyway, we know that, for example, kids who exercise in high ozone are more likely to get asthma, and that higher ozone levels hurt your lungs, so you don't perform quite as well.

When do ozone levels peak? The standard answer is 2 pm to 10 pm. The reality that I've seen lately (and that you can see yourself at http://www.georgiaepd.org/air/amp/) is that levels may peak as early as 5 pm, or as late as 8 pm. It depends on where you are in the city, and particulars of the weather that day, as it's affected by wind direction, sunlight (any clouds?), and your location. You can see monitors all over the metro area, and for half a dozen other Georgia cities, at the Web site.

So, there's air pollution. How can we respond? He are three ways (I think):

-- Ride your bike to work and back, or take MARTA, or stay at home – the goal is to cut pollution. If we took this seriously, and drove 10% less, we could cut the air pollution significantly. The good news is that we ARE driving less, but it's due to $4 a gallon gas, not our sense of civic duty. Still, I'll take it anywhere I can get it.

-- Don't train on these afternoons or evenings. The more you are breathing out, and the harder and deeper you are breathing, the more likely you are to have breathing problems. I would not train outside on a high ozone night; you may work your heart more, but the possibility of lung damage is enough to offset that, if you can avoid it. It's much better to ride at 6 am (and cooler, too).

-- If you must ride (and I do this while biking home), take it easy. I breathe in slowly, through my nose. If I can't do that, but must gasp for air, I'm going too fast, pushing too hard, and I slow down.

-- Keep an eye on the website (above) and try to ride where the ozone is lower. This is not always simple and easy, of course, but I saw that today, for instance, Douglasville was significantly lower than McDonough. This doesn't mean to drive to Douglasville to ride your bike, because levels can change with the wind. It does mean that you might decide to ride or not ride, based on the monitor closest to your riding area or home.

-- The sooner you ride home, the less likely that the ozone will bother you, So ride in at 5 and leave at noon (yeah, we wish!) Because levels may go up in 3-4 hours in the afternoon, you can often see a big difference between 4 pm and 7 pm, say, so don't work late. Maybe you can get a note form your doctor that you have to leave at 3 every high ozone day. Wouldn't that be nice?