10
1. Selenium Pollution Around the World
Lake Huron, some 100 to 200 km away (Hodson et al. 1984). It is important to recognize this source of selenium because, in addition to
contaminating local habitats, smelting can contribute to selenium inputs in distant aquatic systems due to the mechanism by which it is
transported in the atmospheric vapor/particle phase (Small et al. 1981).
This aspect of selenium pollution operates on the same principle as the
acid rain phenomenon-emission of gas-phase pollutants that eventually reach aquatic systems and threaten aquatic life, and that form
deposition/pollution corridors downwind from major sources. Largescale metal smelting operations should be viewed as an important contributor to this phenomenon for selenium.
Municipal Landfills
Although not currently recognized as a widespread cause of selenium
pollution, municipal landfills can generate leachwater that contains
elevated concentrations of selenium (5-50 Ilg Sell) if seleniferous
materials have been disposed there. Noteworthy examples have occurred in the United States, United Kingdom, Sweden, and Hong Kong
(see Table 1.2, Figure 1.1). The source materials for selenium in these
landfills seem to be similar: large amounts of photoelectronic components (rectifiers, capacitors, photocopy printer/toner products, etc.,
which contain/require selenium to operate properly) that were disposed from local computer and electronics manufacturing facilities
(Minnesota Pollution Control Agency [MPCA] 2000; Stockholm Water
Authority [SWA] 2000). Selenium is widely used in electronics because of its photosensitive and semiconducting properties (Sharma and
Singh 1983). The disposal histories of these landfills suggest that selenium-laden leachate could have been released for a number of years
but was only detected recently due to expanded pollution screening
programs mandated by local water quality authorities. The global distribution of electronics and computer/copier industries, coupled with
the practice of landfill disposal of their solid wastes, causes this source
of selenium to pose an important localized threat of selenium contamination. The lesson to be heeded from these examples is that it is
important for contaminant surveillance programs to monitor landfill
leachate for possible selenium contamination. This can be done by
simply including selenium in the list of constituents designated for
chemical analysis.
Oil Transport, Refining, and Utilization
As in the coal industry, procurement and refining of oil produce a
variety of selenium-laden wastes (Table 1. 3). The source of selenium
1. Selenium Pollution Around the World
Lake Huron, some 100 to 200 km away (Hodson et al. 1984). It is important to recognize this source of selenium because, in addition to
contaminating local habitats, smelting can contribute to selenium inputs in distant aquatic systems due to the mechanism by which it is
transported in the atmospheric vapor/particle phase (Small et al. 1981).
This aspect of selenium pollution operates on the same principle as the
acid rain phenomenon-emission of gas-phase pollutants that eventually reach aquatic systems and threaten aquatic life, and that form
deposition/pollution corridors downwind from major sources. Largescale metal smelting operations should be viewed as an important contributor to this phenomenon for selenium.
Municipal Landfills
Although not currently recognized as a widespread cause of selenium
pollution, municipal landfills can generate leachwater that contains
elevated concentrations of selenium (5-50 Ilg Sell) if seleniferous
materials have been disposed there. Noteworthy examples have occurred in the United States, United Kingdom, Sweden, and Hong Kong
(see Table 1.2, Figure 1.1). The source materials for selenium in these
landfills seem to be similar: large amounts of photoelectronic components (rectifiers, capacitors, photocopy printer/toner products, etc.,
which contain/require selenium to operate properly) that were disposed from local computer and electronics manufacturing facilities
(Minnesota Pollution Control Agency [MPCA] 2000; Stockholm Water
Authority [SWA] 2000). Selenium is widely used in electronics because of its photosensitive and semiconducting properties (Sharma and
Singh 1983). The disposal histories of these landfills suggest that selenium-laden leachate could have been released for a number of years
but was only detected recently due to expanded pollution screening
programs mandated by local water quality authorities. The global distribution of electronics and computer/copier industries, coupled with
the practice of landfill disposal of their solid wastes, causes this source
of selenium to pose an important localized threat of selenium contamination. The lesson to be heeded from these examples is that it is
important for contaminant surveillance programs to monitor landfill
leachate for possible selenium contamination. This can be done by
simply including selenium in the list of constituents designated for
chemical analysis.
Oil Transport, Refining, and Utilization
As in the coal industry, procurement and refining of oil produce a
variety of selenium-laden wastes (Table 1. 3). The source of selenium