Please enlighten your earth-conscious fans about the commerce in “pollution futures” at the Chicago Board of Trade. The term suggests that the pollution lobby has invented a sneaky way to poison the air at its own discretion. Don’t the antipollution laws already in place preclude the creation of such “pollution rights”? –Eugene Blahut, Chicago

You’re never going to make it in the PR game with that attitude, Eugene. For starters, you don’t want to call them “pollution futures”; the CBOT would rather you said “clean air futures.” The whole thing sounds a little Machiavellian, but therein lies the genius of it, as we shall see. Even the Environmental Defense Fund thinks pollution futures are cool.

Here’s how it works. The federal Clean Air Act allows companies that reduce pollution to sell “pollution credits” to firms that are still besmirching the skies. The polluters can use the credits to avoid prosecution, having in effect purchased the right to pollute. Sounds sleazy, but actually it’s pretty smart: it rewards companies that reduce their emissions at the expense of those who don’t. It also greatly simplifies enforcement of the antipollution laws, since you don’t get into stupid court battles with polluters who claim they just can’t reduce emissions. You can’t? Fine. Buy your way out of your problems.

There are a variety of pollution credit programs, most of them regional in scope. What the Chicago Board of Trade is involved in is a new national program intended to reduce sulfur dioxide emissions by coal-burning electric utilities. (SO2 is thought to be a leading cause of acid rain.) Last year the feds selected the CBOT to hold an annual auction where utilities can buy and sell “air emission allowances” (i.e., pollution rights). The first auction will be held March 29. The CBOT is doing it for free in the expectation that its members will be able to make money on the side by trading pollution . . . sorry, clean air futures–that is, the right to buy a set quantity of emission allowances at a set price at a set future date. The utilities that buy and sell futures do so because they want to lock in their future revenues and expenses; the traders want to trade them because the future-contract price of the emission allowances will probably differ from the actual price, and they hope to make money on the difference. Sounds confusing, but if people can make millions selling pork belly futures (and they have), they can do the same with pollution. But, you object, they’re trafficking in our planet’s future! Well, yeah, I guess they are. But if we’ve learned one thing in America, it’s that if people can make money on the deal, they’re more likely to go along with the program.

In days of old, doctors wore metal disks with a hole in the middle on their heads, which made them look like a coal miner or a shaman. What was the disk and where did it go? –Evan and Yishai, Oakland, California

Cecil has heard various terms for this, but the simplest, most descriptive, and therefore most unmedical is “head mirror.” It was used in examinations of the ear, throat, and other, ah, body cavities. To use, you swung the head mirror down so that you could look through the hole in the middle with one eye. Then you positioned a light source so that it shone on the mirror’s parabolic surface. By moving your head just so, you could reflect the light rays down the patient’s throat or whatever, the better to illuminate items of interest without obstructing the view. Just about all doctors used head mirrors at one time, and they became, along with the stethoscope, one of the symbols of the profession. But they could be a bit of a hassle to use and they did make you look like a space alien, so today many doctors prefer a penlight or other examining device. Some ENT (ear-nose-throat) specialists still use head mirrors, though, so look one up if you get nostalgic.

Art accompanying story in printed newspaper (not available in this archive): illustration/Slug Signorino.