A bad trade.

Byline: The Register-Guard

Give one child two sandwiches and another child none. The average is one sandwich apiece, but that doesn't mean both kids have had lunch. Similarly, the Environmental Protection Agency should not expect people in the Northwest to be happy with a proposed rule that cuts harmful benzene pollution by one-third nationwide, but leaves the Northwest with higher benzene levels than the current national average.

Benzene is a known carcinogen, and its primary source is vehicle exhaust. The amount of benzene coming from tailpipes depends on how gasoline is formulated.

Gasoline from the four refineries in Washington state that supply Oregon contains 2.06 percent benzene by volume. That's more than twice the national average of 0.97 percent. Gas sold in the Northwest has been allowed to have the nation's highest benzene content as a perverse reward for having air that is generally clean.

The health effects of the compound have led the EPA to propose a nationwide reduction in the benzene content of gasoline - from the current 0.97 percent to a national average of 0.62 percent. Refineries that succeeded in cutting benzene content below the 0.62 percent standard would receive credits for their success. These credits could be sold to refineries elsewhere, and the purchasers would use the credits to buy permission to exceed the 0.62 percent level.

On average, everyone gets a sandwich. In practice, benzene levels in some parts of the country would be reduced to as little as 0.29 percent, generating credits that would be bought by Northwest refineries, allowing them to produce gasoline with benzene content of 1.04 percent. That's higher than the current average that the EPA proposes to reduce for health reasons, and 40 percent above the proposed standard.

The EPA reasons that the Northwest is lightly populated compared to many other parts of the country, and has fewer vehicles polluting a given volume of air. That reasoning is unpersuasive to residents of Eugene, where benzene levels 10 times higher than those thought to cause cancer as a result of lifetime exposure have been recorded. The only way to avoid such exposure is to stop breathing.

The proposed benzene rule illustrates the unfairness of some pollution credit-trading systems. If a pollutant is distributed nationally or globally, as is the case with greenhouse gases, trading mechanisms can help polluters meet new emissions targets. But if the effects of a pollutant are local or regional, as is the case with benzene, some areas suffer disproportionate environmental or health effects.

The reason for a standard allowing regional disparities, of course, is cost - about $6 million for each refinery upgrade, according to the EPA. Refinery operators say the cost of upgrades is higher, and hope to save money by retrofitting only some of their facilities.

Federal benzene rules, however, shouldn't produce winners and losers. If benzene exposure creates a health risk that can be reduced by proven and affordable changes in refinery operations, the benefits of that reduction should be shared by everyone. The EPA ought to set a uniform national benzene content standard and set a deadline for refineries to meet it. People in the Northwest shouldn't have to breathe more poison than people in other parts of the country.