Mercury in the terrestrial environment: a review

Environmental Sciences Europe

Table 5 Summary of mercury fluxes from terrestrial regions [38]

Region	Evasion (average) (Mg year⁻¹)	Ratio^a (%)
Forest	342	7,5
Tundra/grassland/savannah/prairie/chaparral	448	9,9
Desert/metalliferous/non-vegetated zones	546	12,0
Agricultural areas	128	2,8
Evasion after mercury depletion events^b	200	4,4
Total	1664	–
Volcanoes and geothermal areas	90	–
Biomass burning	675	–

^aCalculated over the total evasion from natural sources which sum 4532 Mg year⁻¹
^bFriedli [42] and Mason [68] distinguish as a natural source of mercury emission to the atmospheric air of regions where there are episodes of sudden decreases in mercury concentrations in the air by deposition to the ground and then reemission. These phenomena occur mainly in the Arctic regions and Antarctica, and the emission from this source is estimated at 200 Mg year⁻¹