They used to put lead in gasoline. People liked the way it made their cars run, but the damage all that lead in the environment did to people’s health was not worth it.

Most of us grew up with mercury fever thermometers in the bathroom medicine cabinet.

But the cumulative effect of so many thermometers breaking and releasing mercury into the waste stream and water table created too big a threat to health and safety to be tolerated.

We are at a similar point in the history of single-use polystyrene packaging. The popular foam cups and burger boxes are made from petroleum. They contain styrene, which the National Institutes of Health lists as one of the substances that are “reasonably considered to be human carcinogens.”

The containers are rarely recycled and end up in landfills, where they will remain virtually forever, or burned in incinerators, releasing toxins into the atmosphere.

There is an alternative. The city of Portland is considering an ordinance that would greatly reduce the use of polystyrene by banning foam cups and containers in the city’s eateries. That is a reasonable response to a hazardous pollutant that seems safe only because it is so common.

A number of cities out west have recently banned these containers, but Portland doesn’t have to look that far for a model.

The town of Freeport banned foam cups and fast-food containers in 1990. Some of the biggest chain restaurants in the nation, along with small, local businesses, have managed to adapt. Businesses in Portland would be able to do the same, and so would consumers.

If more cities follow suit, there will be fewer foam products in the waste stream, reducing a health risk. And as the products disappear, the price for alternatives will decrease and consumers will forget they ever relied on the containers to keep their food and drinks warm.

We’ve been through this kind of thing before. People liked leaded gas and mercury thermometers, but the convenience wasn’t worth the damage those products caused.

We would be better off with less foam, and Portland officials are right to start cutting its use here.