About one-third of the toxic metal, mercury (Hg), is released into the air from natural sources, such as rocks, soil, volcanoes, and the ocean. The remaining two-thirds comes from .

Human activities

Explanation:

Anthropogenic activities account for the major sources of pollution of the environment. Various human activities contribute in no small way to environmental degradation.

Two-thirds of toxic metal, mercury (Hg) is released into the environment by human activities.

One of the human activities that release mercury into the environment is the extraction of metals such as sodium which requires an amalgam of sodium and mercury.

Mining and fossil fuel combustion also releases mercury in large quantities. This mercury so released leads to contamination of the environment.