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 ____. a. human activities
b. waste from livestock
c. airplane exhaust
d. automobile exhaust
e. mercury-rich plants
<span>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.</span><span />