Pros: Used in scientific instruments (thermometers and barometers).
Cons: Highly toxic ( damages brain, nerves, kidneys, and can cause birth defects).
Mercury is found as an ore in a comination with Cinnabar. It tends to be found in high concentrations in geographic regions where there are hot springs and volcanoes. Therefore, it is extracted from Cinnabar from a simple process of heating and collecting the vapors.
Mercury in the air may settle into water bodies and affect water quality. This airborne mercury can fall to the ground in raindrops, in dust, or simply due to gravity (known as "air deposition"). After the mercury falls, it can end up in streams, lakes, or estuaries, where it can be tranfered to methylmercury through microbial activity.
_A serious industrial disaster was the dumping of mercury compunds into Minamata Bay, Japan. It is estimated that over 3,000 people suffered various deformities, severe mercury poisioning symptons or death from what became known as Minamata disease.
Fishing in Minamota Bay caused poisoning from the mercury-ingested fish that the Japanese ate.