10
R. Ebinghaus et al.
(Petersen et al. 1995). Although these species are typically present at less than
10% of the total atmospheric mercury, they appear to influence the deposition
flux significantly (Petersen et al. 1996; Pai et al. 1997).
Any oxidized Hg species will be subject to wet and dry deposition because of
its significantly higher deposition velocity compared with elemental mercury
(Lindberg et al. 1992; Lindberg and Stratton 1998).
A major fraction of the total mercury in precipitation is associated with
particles, at least in urban and industrialized areas (Ferrara et al. 1988; Iverfeldt
1991), although it is not clear if this association occurs before or after rain
formation. The particulate fraction in precipitation varies between less than 10%
at remote sites to more than 90% at polluted sites (Iverfeldt 1991; Ebinghaus et al.
1995).
Gaseous methylmercury will not influence the total deposition of mercury to
any great extent (Petersen et al. 1995). It may, however, constitute an important
contribution to the overall loadings of methylmercury in terrestrial and aquatic
ecosystems (Hultberg et al. 1995). Methylmercury is present in precipitation at
concentrations generally corresponding to around 5% of the total Hg (Bloom and
Watras 1988; Hultberg et al. 1995; Munthe et al. 1995; Petersen et al. 1996);
however, the sources of this methylmercury are still not known. Bloom et al.
(1996a) and Carpi et al. (1998) have each presented evidence for atmospheric
methylmercury emissions from marine and continental sources, respectively.
3
Sources and Magnitudes of Anthropogenic Emissions
Mining, smelting, and refining of metals and their myriad applications have
resulted in the mobilization and dispersion oflarge amounts of heavy metals into
the environment. Emissions into the atmosphere during extraction, production,
fabrication, application, and end-use have resulted in the widespread distribution of their compounds, including mercury. While the emissions in the
developed countries are relatively well quantified, those in the developing world
are poorly known.
The main types of anthropogenic emission sources maybe categorized as
follows (Porcella et al. 1996):
1. Combustion
Fossil fuels (coal, oil, gas) and wood
Wastes (municipal, medical, hazardous wastes)
Sewage sludge
Crematories
2. High temperature processes
Smelting
Coking
Ore roasting
Cement and lime production
R. Ebinghaus et al.
(Petersen et al. 1995). Although these species are typically present at less than
10% of the total atmospheric mercury, they appear to influence the deposition
flux significantly (Petersen et al. 1996; Pai et al. 1997).
Any oxidized Hg species will be subject to wet and dry deposition because of
its significantly higher deposition velocity compared with elemental mercury
(Lindberg et al. 1992; Lindberg and Stratton 1998).
A major fraction of the total mercury in precipitation is associated with
particles, at least in urban and industrialized areas (Ferrara et al. 1988; Iverfeldt
1991), although it is not clear if this association occurs before or after rain
formation. The particulate fraction in precipitation varies between less than 10%
at remote sites to more than 90% at polluted sites (Iverfeldt 1991; Ebinghaus et al.
1995).
Gaseous methylmercury will not influence the total deposition of mercury to
any great extent (Petersen et al. 1995). It may, however, constitute an important
contribution to the overall loadings of methylmercury in terrestrial and aquatic
ecosystems (Hultberg et al. 1995). Methylmercury is present in precipitation at
concentrations generally corresponding to around 5% of the total Hg (Bloom and
Watras 1988; Hultberg et al. 1995; Munthe et al. 1995; Petersen et al. 1996);
however, the sources of this methylmercury are still not known. Bloom et al.
(1996a) and Carpi et al. (1998) have each presented evidence for atmospheric
methylmercury emissions from marine and continental sources, respectively.
3
Sources and Magnitudes of Anthropogenic Emissions
Mining, smelting, and refining of metals and their myriad applications have
resulted in the mobilization and dispersion oflarge amounts of heavy metals into
the environment. Emissions into the atmosphere during extraction, production,
fabrication, application, and end-use have resulted in the widespread distribution of their compounds, including mercury. While the emissions in the
developed countries are relatively well quantified, those in the developing world
are poorly known.
The main types of anthropogenic emission sources maybe categorized as
follows (Porcella et al. 1996):
1. Combustion
Fossil fuels (coal, oil, gas) and wood
Wastes (municipal, medical, hazardous wastes)
Sewage sludge
Crematories
2. High temperature processes
Smelting
Coking
Ore roasting
Cement and lime production