Through these two different measurements, researchers were able to make a complex picture of the spread of mercury due to industrial runoff both spatially and temporally.

The technology is used by businesses, schools and some local governments to purify toilet water, industrial runoff and contaminated bodies of water.

Logging activity, agricultural and industrial runoff, and gravel removal all pose threats as well.

A pond of industrial runoff is nearby.

Some examples include agricultural and industrial runoff, increased sedimentation from land clearing, human sewage and toxic discharges.

The students say it is their duty to keep the shallow, narrow creek free of lawn fertilizer, industrial runoff, litter and other encroachments.

Most of Kazakhstan's water supply has been polluted by industrial and agricultural runoff and, in some places, radioactivity.

Once a polluted waterway due to raw sewage and industrial runoff, it has become cleaner in recent years.

But now overfishing, raw sewage and industrial and farm runoff have made the Black Sea one of the planet's most damaged waters.

That includes the dumping of untreated sewage or industrial runoff into the ocean.