Many of the Earth’s elements travel or cycle through the natural environment. This means that they are transported from the soil into nearby lakes and rivers, and then evaporate from the water into the air, to be transported by wind and eventually re-deposited to the surface where the cycle starts over again. Mercury cycles through the environment in this way (see Figure 5). An atom of mercury may begin its journey by being eroded from rocks on the shore of a lake or by being vented into the atmosphere as mercury vapour from a volcanic eruption. These are natural emissions. However, more than half of the mercury.
