In the 1980s and 1990s, chemical pollution was discovered in the town's wells.

The waters around Boulay have also been affected by bacterial and chemical pollution.

In 1996 herpetologists discovered other reasons for these mutations were due to chemical pollution.

The species is sensitive to low levels of dissolved oxygen, and to chemical pollution.

The springs have very little chemical pollution, and low turbidity.

Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species.

The culprits might include chemical pollution, disease and increasing ultraviolet light.

LaNell began after learning she had a rare immune system disease associated with chemical pollution.

These agencies are mandated watchdogs of industry and regulate releasing chemical pollution into the environment.

There's only so much thermal and chemical pollution you can dump before your factories begin to poison themselves.