Save gas, clean the air.

Byline: The Register-Guard

With petroleum prices edging above $80 a barrel and gasoline prices likely to follow the same upward path, economic incentives should be sufficient to encourage Americans to conserve fuel whenever possible. But just in case further encouragement is needed, the Lane County Board of Commissioners has shown how to obtain another benefit from efforts to save gasoline: reduced benzene pollution.

The board voted unanimously last week to encourage county employees to refrain from topping off the fuel tanks in county vehicles, and to avoid leaving engines idling for more than 20 seconds. Both those steps will result in modest reductions in fuel use - but with gasoline at $2.70 a gallon, every savings helps. These simple conservation measures will also have the important effect of reducing the amount of benzene in the atmosphere.

Benzene is a common industrial hydrocarbon that evaporates quickly. The vapor is heavier than air, so it can accumulate at ground level. Benzene enters the air from many sources, ranging from tobacco smoke to volcanoes. But a primary source is gasoline, and high concentrations of benzene are often found in places where gasoline has an opportunity to vaporize - particularly near gas stations.

Benzene is a known carcinogen. In one study, children's risk of developing leukemia was increased fourfold by living near gas stations. Gas station employees - and Oregon is one of two states where gasoline must be pumped by an attendant - are exposed to high levels of benzene in the course of their work. Such exposure can have both short-term and long-term health effects ranging from dizziness to anemia and other blood disorders. And because of a system of emissions trading, gasoline refined in the Northwest has relatively high benzene levels.

Human exposure to benzene can be reduced by giving gasoline fewer chances to vaporize. That's where the no top-off rule comes in: When a gas tank is filled beyond its automatic shutoff level, spills are likely to occur - and when gasoline is spilled, benzene gets into the air. By 2009, all new vehicles sold in Oregon will be required to have vapor-recovery mechanisms in their fuel tanks; overfilling can also defeat this equipment. Shorter idling times will reduce the amount of benzene that enters the atmosphere through vehicle tailpipes.

Everyone can do what the board has asked county employees to do - indeed, people can go further by checking to ensure that their gas caps seal tightly, both on vehicle fuel tanks and on gas cans used to store fuel for lawnmowers and other gas-powered home equipment. Gas station owners can also be encouraged to install systems that recover vapors when fuel is delivered to storage tanks. Such systems are already required in Portland, Salem and Medford.

In the case of benzene reduction, public health and economic interests coincide. The county board has outlined easy ways to burn less fuel, save money and clear the air all at once. There's no trade-off - these steps are all benefit, no cost.