Stay home, close the doors, draw the shades, forget the lawn, raise the thermostat, keep the kids inside, do not paint the deck, do not paint your fingernails, do not touch the barbecue fluid and, Baltimore, do not - repeat, DO NOT - apply hair- spray.
It was an Ozone Action Day.
Yesterday was not only Ozone Action Day but also the first OAD of the Ozone Season, which is now an annual event in Maryland life, marking the languid stretch of days ranging from May 1 to Sept. 30, corresponding with highway vacations and outdoor barbecues and the mindless pleasure of applying the power of crude rotary engines to the art of gardening. If it is not as celebrated as Opening Day, as anticipated as the first pitch at Camden Yards, then it is at least now as regular as the first drifting leaf of autumn, as meaningful as the last frost in spring.
Do not fear OAD. It's regular. It's seasonal. It's chemical.
Charles Piety had seen it coming. As early as Friday, the 37-year-old air-quality forecaster from the University of Maryland watched with his colleagues as the wind direction switched from its usual southerly flow to southwest to west, swinging clockwise. Winds weren't coming from off the ocean anymore.
He also noticed a warming trend, a drop in wind speed, a high-pressure system clearing out the clouds and there, looking at the lower layer of the atmosphere from the surface to 5,000 feet where air quality forecasters take a special interest, the top of the "boundary layer" was warming.
Warm at the top. Warm at the bottom. Not much good for a convection current. A dog like that don't hunt; air like that won't mix. Air like that goes nowhere.
Charles Piety saw it coming.
You could slip outdoors yesterday at 3 o'clock, when an ozone monitor in Harford County was the first in the state to tip into the Red Zone, and step into a rancid, 91-degree bath of air, taste a fetid breeze and enjoy a stagnant pool of dishwater "blue" sky overhead that screamed, like an umpire bellowing for the first pitch, "Ozone!" At 129 parts per billion from the monitor on Waeli and Owen roads, it had become a red-letter day. Once again, the state of Maryland extended its streak for "non-attainment" of an air-quality standard that limits ozone levels to 120 parts per billion.
Over the last 10 years, the Baltimore region has averaged 10 Code Red air pollution alerts annually, days when ground-level ozone surpassed federal health standards. Last year, the first Ozone Action Day didn't happen until June 12.
Yesterday was just June 11, and already the streak was on.
Honestly, there's nothing to fear. Relax. Take a deep breath.
"It is a little bit exciting," confessed Piety, who at noon had yet to see an ozone monitor break the 120 ppb limit. "Because this is what we do. We are waiting for the condition to be ripe for poor air quality and then try to make that decision, yes or no. And when we forecast yes ... well, we certainly don't want people to experience poor air quality, but it's like a weather forecaster who says 'Six inches of snow' and there's no snow. We don't want to see high levels of ozone, but we don't want to be wrong, honestly. So it's an anxious time for us, and a little bit exciting."
Yesterday Piety car-pooled to work. Some days, he rides his bike, but not on an OAD. Ozone is a lung irritant. It can give you headaches. It can make your lungs sting. It can compromise a body's immune system.
"It is a little unsettling," he acknowledged.
When you think about it, 120 parts per billion does not sound like much. That means out of a billion molecules in the air that a person might breathe, only 120 of them are ozone molecules. An ozone molecule is nothing more than an oxygen molecule with an extra oxygen atom. Sure, it's unstable. It reacts with other compounds. OK, you don't want to breathe a lot of it.
But that's what an OAD is for.
The Baltimore/Washington area has violated the standard for ozone so often that it now has to institute a plan that will stop days like yesterday. That's why the state issues the Code Red forecasts and asks people not to fuel their cars until after dusk and quit mowing their lawns for a day and car-pool to work.
Some companies give their employees free sodas at lunch to keep people from driving out to lunch. They even ask people not to use hairspray - that's a fact.
By 2005, there should be no more OADs. Even today should be safe.
But there's really no need to worry. Breathe deeply. Stay calm. Retreat into the land of perpetual spring.
Ah, air conditioning!