The plant also was a major source of pollution, another key issue brought to light in the late 1960s.

It is also a primary source of pollution for the river.

This has become a primary source of pollution for the river.

Close to sources of pollution, it will take longer to meet the environmental quality standards.

One pollution source is a remnant of the cold war.

However, it later turned out that the paper mill was a source of huge pollution in the region.

Isn't that just transferring the pollution source from the car to the plant?

There were few pollution sources anywhere now, even with the Recovery well along.

They set standards for sometimes specific sources of pollution like automobiles.

But he said the nation still had a long way to go in halting other sources of pollution.