90
R.R. Turner and G.R. Southworth
lost in wastewater far in excess of that expected from the solubility of the pure
metal (about 60 ~lg 1-'). Oxidation to more soluble compounds (e.g., mercuric
oxide 53 mg 1-') plus water-borne transport of microscopic metallic particles
greatly enhanced historic losses via wastewater.
Those industries which incorporated mercury or one of its numerous
compounds into products represent one potential type of enviromental release.
Spills of mercury feedstocks and disposals of off-specification products at
fungicide, paint, electrical, and explosives manufacturing facilities are some
historical examples. These types of industries have mostly discontinued use of
mercury (fungicides, paint) or greatly decreased the quantities (batteries)
incorporated. Use of mercury as a preservative in forest and agricultural
products has also virtually stopped, but legacies of such former use are still
present. One also finds examples where mercury was not used directly in a
consumable product but was used to test materials (e.g., porosimetry), to
measure processes (e.g., natural gas flow using manometers), or as a functional
component of apparatus (e.g., pumps and seals). In some cases, facilities which
were built to reclaim mercury and other resources from discarded products (e.g.,
battery recyclers) have led to severe environmental contamination (e.g., NYSDEC
1992). Lastly, there are numerous cases where mercury was used to manufacture
a product but the product(s) did not intentionally contain mercury. Production
of caustic soda, chlorine, acetaldehyde, and certain plastics are the main
examples.
Environmental regulation of releases of mercury began in the US and Canada
about 1970 partly as a general consequence of the environmental activism which
began in the late 1960s but also as a very specific consequence of scientific
revelations which showed that inorganic mercury could be methylated in the
environment and lead to levels in fish and other high-level predators which posed
a human health risk. By some accounts (D'Itri 1972), the first significant focus on
mercury in North America began in the St Clair River and associated waterways
(Lake St Clair and Detroit River) which connect Lake Huron and Lake Erie. In
late 1969 and early 1970, fish from these waters were found to be contaminated
with mercury from two chloralkali plants, one in the US and one in Canada,
which discharged wastewater into this aquatic system. This discovery led very
quickly to polling of all industries in the US and Canada (e.g., DOl 1970) which
might be using mercury, monitoring of their discharges, and monitoring of fish
in the receiving waters. The results showed high discharges of mercury from
some industries and associated contamination of fish. Most offending industries
very quickly reduced or eliminated discharges, and a few soon ceased operations
entirely.
Regulation of industrial discharges in the 1970S and early 1980s continued to
focus mainly on aquatic releases until the passage of two important environmental laws [Resource Conservation and Recovery Act (RCRA) in 1978 (amended
1986-1987) and Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA) in 1980 (amended in 1986)] in the United States
effectively expanded coverage to include disposal of industrial mercury-bearing
wastes (RCRA) and restoration of sites contaminated prior to most environmental regulations (CERCLA). These, and similar laws in Canada and Mexico,
R.R. Turner and G.R. Southworth
lost in wastewater far in excess of that expected from the solubility of the pure
metal (about 60 ~lg 1-'). Oxidation to more soluble compounds (e.g., mercuric
oxide 53 mg 1-') plus water-borne transport of microscopic metallic particles
greatly enhanced historic losses via wastewater.
Those industries which incorporated mercury or one of its numerous
compounds into products represent one potential type of enviromental release.
Spills of mercury feedstocks and disposals of off-specification products at
fungicide, paint, electrical, and explosives manufacturing facilities are some
historical examples. These types of industries have mostly discontinued use of
mercury (fungicides, paint) or greatly decreased the quantities (batteries)
incorporated. Use of mercury as a preservative in forest and agricultural
products has also virtually stopped, but legacies of such former use are still
present. One also finds examples where mercury was not used directly in a
consumable product but was used to test materials (e.g., porosimetry), to
measure processes (e.g., natural gas flow using manometers), or as a functional
component of apparatus (e.g., pumps and seals). In some cases, facilities which
were built to reclaim mercury and other resources from discarded products (e.g.,
battery recyclers) have led to severe environmental contamination (e.g., NYSDEC
1992). Lastly, there are numerous cases where mercury was used to manufacture
a product but the product(s) did not intentionally contain mercury. Production
of caustic soda, chlorine, acetaldehyde, and certain plastics are the main
examples.
Environmental regulation of releases of mercury began in the US and Canada
about 1970 partly as a general consequence of the environmental activism which
began in the late 1960s but also as a very specific consequence of scientific
revelations which showed that inorganic mercury could be methylated in the
environment and lead to levels in fish and other high-level predators which posed
a human health risk. By some accounts (D'Itri 1972), the first significant focus on
mercury in North America began in the St Clair River and associated waterways
(Lake St Clair and Detroit River) which connect Lake Huron and Lake Erie. In
late 1969 and early 1970, fish from these waters were found to be contaminated
with mercury from two chloralkali plants, one in the US and one in Canada,
which discharged wastewater into this aquatic system. This discovery led very
quickly to polling of all industries in the US and Canada (e.g., DOl 1970) which
might be using mercury, monitoring of their discharges, and monitoring of fish
in the receiving waters. The results showed high discharges of mercury from
some industries and associated contamination of fish. Most offending industries
very quickly reduced or eliminated discharges, and a few soon ceased operations
entirely.
Regulation of industrial discharges in the 1970S and early 1980s continued to
focus mainly on aquatic releases until the passage of two important environmental laws [Resource Conservation and Recovery Act (RCRA) in 1978 (amended
1986-1987) and Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA) in 1980 (amended in 1986)] in the United States
effectively expanded coverage to include disposal of industrial mercury-bearing
wastes (RCRA) and restoration of sites contaminated prior to most environmental regulations (CERCLA). These, and similar laws in Canada and Mexico,