Natural and Anthropogenic Mercury Sources
and Their Impact on the Air-Surface Exchange
of Mercury on Regional and Global Scales
R. EBINGHAUS, R.M. TRIPATHI, D. W ALLSCHLAGER, and S.E. LINDBERG
1
Introduction
Mercury is outstanding among the global environmental pollutants of continuing
concern. Especially in the last decade of the 20th century, environmental
scientists, legislators, politicians and the public have become aware of mercury
pollution in the global environment. It has often been suggested that anthropogenic emissions are leading to a general increase in mercury on local, regional,
and global scales (Lindqvist et al. 1991; Expert Panel 1994).
Mercury is emitted into the atmosphere from a number of natural as well as
anthropogenic sources. In contrast with most of the other heavy metals, mercury
and many of its compounds behave exceptionally in the environment due to their
volatility and capability for methylation.
Long-range atmospheric transport of mercury, its transformation to more
toxic methylmercury compounds, and their bioaccumulation in the aquatic
foodchain have motivated intensive research on mercury as a pollutant of global
concern. Mercury takes part in a number of complex environmental cycles, and
special interest is focused on the aquatic-biological and the atmospheric cycles.
Environmental cycling of mercury can be described as a series of processes where
chemical and physical transformations are the governing factors for the
distribution of mercury in and between different compartments of the
environment. Mercury can exist in a large number of different physical and
chemical forms with a wide range of physical, chemical, and ecotoxicological
properties and consequently with fundamental importance for the environmental
behavior. The three most important chemical forms known to occur in the
environment are: elemental mercury [Hg(o)], which has a high vapor pressure
and a relatively low solubility in water; divalent inorganic mercury (Hg2+), which
can be far more soluble and has a strong affinity for many inorganic and organic
ligands, especially those containing sulphur; and methylmercury (CH3Hg+),
which is strongly accumulated by living organisms. Conversions between these
different forms provide the basis of mercury's complex distribution pattern on
local, regional, and global scales.
This chapter was prepared while R.M.T. and S.E.L. were visiting scientists at the Institute of Physical
and Chemical Analysis at GKSS Research Centre, Geesthacht, Germany. Publication number 4745,
Environ. Sci. Div. Oak Ridge National Lab.
Environmental Science
Mercury Contaminated Sites (ed. by R. Ebinghaus et al.)
© Springer-Verlag Berlin Heidelberg 1999
and Their Impact on the Air-Surface Exchange
of Mercury on Regional and Global Scales
R. EBINGHAUS, R.M. TRIPATHI, D. W ALLSCHLAGER, and S.E. LINDBERG
1
Introduction
Mercury is outstanding among the global environmental pollutants of continuing
concern. Especially in the last decade of the 20th century, environmental
scientists, legislators, politicians and the public have become aware of mercury
pollution in the global environment. It has often been suggested that anthropogenic emissions are leading to a general increase in mercury on local, regional,
and global scales (Lindqvist et al. 1991; Expert Panel 1994).
Mercury is emitted into the atmosphere from a number of natural as well as
anthropogenic sources. In contrast with most of the other heavy metals, mercury
and many of its compounds behave exceptionally in the environment due to their
volatility and capability for methylation.
Long-range atmospheric transport of mercury, its transformation to more
toxic methylmercury compounds, and their bioaccumulation in the aquatic
foodchain have motivated intensive research on mercury as a pollutant of global
concern. Mercury takes part in a number of complex environmental cycles, and
special interest is focused on the aquatic-biological and the atmospheric cycles.
Environmental cycling of mercury can be described as a series of processes where
chemical and physical transformations are the governing factors for the
distribution of mercury in and between different compartments of the
environment. Mercury can exist in a large number of different physical and
chemical forms with a wide range of physical, chemical, and ecotoxicological
properties and consequently with fundamental importance for the environmental
behavior. The three most important chemical forms known to occur in the
environment are: elemental mercury [Hg(o)], which has a high vapor pressure
and a relatively low solubility in water; divalent inorganic mercury (Hg2+), which
can be far more soluble and has a strong affinity for many inorganic and organic
ligands, especially those containing sulphur; and methylmercury (CH3Hg+),
which is strongly accumulated by living organisms. Conversions between these
different forms provide the basis of mercury's complex distribution pattern on
local, regional, and global scales.
This chapter was prepared while R.M.T. and S.E.L. were visiting scientists at the Institute of Physical
and Chemical Analysis at GKSS Research Centre, Geesthacht, Germany. Publication number 4745,
Environ. Sci. Div. Oak Ridge National Lab.
Environmental Science
Mercury Contaminated Sites (ed. by R. Ebinghaus et al.)
© Springer-Verlag Berlin Heidelberg 1999