Smog is good for your tan

>> Too bad it makes people sick

by PHILIP PREVILLE

There's too much ozone in the air.

Especially in the summer, from June to September, when the sun is shining and it's really, really hot. So says Claude Gagnon, envirocrat with the Montreal Urban Community's environment department.

To anyone familiar with that thing known as the hole in the ozone layer, Gagnon doesn't make much sense. Sounds like a load of government propaganda, manufactured in order to make us believe that the planet is not going to hell in a rusted-out toxic handcart. The kind of thing the Globe and Mail would write about. "Ozone supply exceeds demand," the headline would read. Or maybe Gagnon is talking about a different kind of ozone, that other ozone that no one ever talks about.

Gagnon insists he's telling the truth, and that ozone is ozone. In order to understand what he's getting at, you have to stop thinking in terms of geo-politics and start thinking in terms of strato-politics. "We don't have enough ozone about 40 kms from the earth's surface," he explains, "but at ground level we've got too much of it." We manufacture it and release it into the atmosphere constantly, he continues, and up it goes. But it's an unstable chemical, so it deteriorates before it can make its way up to patch the hole in the ozone layer.

What Gagnon is trying to say is that ozone is the principal ingredient of summer urban smog. It is the component that makes smog visible to the eye--or, perhaps more precisely, it's the component of smog that reduces visibility. So when you're peering at the city through the summer haze, you're actually looking though a thin film of the most valuable chemical on earth.

(Summer smog may or may not have a yellowish-brown colour, depending on the concentration in the air of nitrates--essentially the same compounds that colour people's urine.)

And there's another dimension to the ozone riddle: smog is almost entirely the result of automobile emissions, and yet cars don't emit ozone. "It's the heat that does it," says Gagnon. "Car emissions rise into the air, and the heat causes them to react and produce ozone. In the winter, that doesn't happen. That's why you never get the haze in winter."

As a result, summer smog shares some of the same properties as the ozone layer: smog filters sunlight and actually protects the city from the sun's rays. But the ozone concentrations are not high enough to serve as a total replacement for the hole in the ozone layer.

For sunbathers, then, logic dictates that we need more smog. There is a way to check up on the day's ozone concentration: the subway platform at McGill metro station features a large electronic board which measures the quality of air in the downtown area. According to Gagnon, the McGill metro "envirotron" is electronically hooked up to an MUC environmental monitoring station atop a building at Metcalfe and de Maisonneuve, one of 15 such stations on the island of Montreal. The envirotron--the only one of its kind in Canada--constantly updates the levels of ozone, particulates, and other smog compounds, and rates air quality on a scale of "good," "acceptable," or "bad."

Commuters, however, aren't convinced of the envirotron's usefulness. Peggy Messing, who stares up at the board every day while waiting for the metro after work, figures the envirotron is a waste of copper wiring. "It doesn't make sense," Messing says. "It always says 'good,' and I just believe it naïvely. But it seems kind of dumb to monitor the air quality without doing anything about it."

That's where envirocrat Gagnon steps aside and medi-crat Louis Drouin, an MD with the city of Montreal's Department of Environmental Health, steps in. Montreal and most other Canadian cities keep track of noxious air compounds on a daily basis, then compare that information with hospital data to find out which compounds have harmful effects on health. According to Drouin, the research points a nasty finger of blame at ozone.

"On the days when the ozone level in the atmosphere reaches its peak, hospital visits for respiratory problems also go up," Drouin says. "Ozone is probably responsible for about four to five per cent of all medical consultations during the summer."

The only answer, Drouin says, is to reduce automobile emissions by encouraging people to use public transit. According to Montreal's Metropolitan Transport Agency, the number of commuters using cars has gone up in the last five years.

Drouin says getting people to take the bus and/or metro is increasingly complex. More people are using cars, but not because they have lots of money to spend or because they enjoy the luxury. "The reasons for the increase in cars are very complicated," says Drouin. "Today, in most cases, both men and women are commuting to work. Kids need to be dropped off at the daycare. People need to pick up groceries and run other errands on the way home.

"It's pretty much impossible to ask people to do all that on buses and metros."

--With a report from Jessica Howard