as to fish. Because of the PBT properties, important is also their bioaccumulation and
chronic toxic effects in non-target organisms at the top of the food chain like birds or
mammals. The group of “old” legacy OCPs (regulated by UNEP Stockholm Convention) includes well-known DDT, which is transformed in the environment to its
metabolites DDE and DDD. Other examples are so-called “drin” pesticides (aldrin,
dieldrin, chlordane, endrin, mirex, toxaphene) or gamma isomer of
hexachlorocyclohexane known as lindane. In addition to the acute toxicity, systemic
toxic effects upon chronic exposures include (like other POP compounds) endocrine
disruptive effects, developmental toxicity and teratogenicity, tumor promotion,
immunosuppressions, etc.
27.6.6 Toxic Metals
Anthropogenic use of many metals and metalloids, such as arsenic, As, results in
major environmental loads. In the following paragraphs, we briefly introduce
relevant information on ecotoxicity of the selected representatives—Hg and also
Cd, Pb, Cu.
27.6.6.1 Mercury
Hg is found in small concentrations in many rocks, and, therefore, certain natural
background levels can be detected in soils, air, and water around the world. Its
mining and industrial applications have increased significantly since the industrial
revolution. Other releases typically include waste incineration, coal combustion,
base metal smelting, chlor-alkali industry, small-scale gold mining, use in dental
amalgam as well as use in artisanal jewelry and trinkets for tourists in certain regions.
Mercury has been recognized as a serious threat within the UN Environment
Minamata Convention. It is known for its characteristic environmental fate that
includes formation of organo-mercury species (e.g., methyl Hg) by microorganisms
in abiotic conditions like sediments, which may easily enter the food chain and
become bioaccumulated. Moreover, they have also been shown more toxic than the
inorganic mercury. Some well-known effects in humans include neuropathies,
developmental disruptions (Minamata disease), or kidney problems. Invertebrates
display variable sensitivity, and concentrations as low as 0.04 μg/L were shown to
inhibit reproduction in Daphnia magna (Biesinger et al. 1982). For freshwater fish,
inorganic mercury is not as toxic as some other metals like Cu, Pg, Zn, or Cd with
96 h LC50 ranging in hundreds of μg/L (Table 27.3).
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chronic toxic effects in non-target organisms at the top of the food chain like birds or
mammals. The group of “old” legacy OCPs (regulated by UNEP Stockholm Convention) includes well-known DDT, which is transformed in the environment to its
metabolites DDE and DDD. Other examples are so-called “drin” pesticides (aldrin,
dieldrin, chlordane, endrin, mirex, toxaphene) or gamma isomer of
hexachlorocyclohexane known as lindane. In addition to the acute toxicity, systemic
toxic effects upon chronic exposures include (like other POP compounds) endocrine
disruptive effects, developmental toxicity and teratogenicity, tumor promotion,
immunosuppressions, etc.
27.6.6 Toxic Metals
Anthropogenic use of many metals and metalloids, such as arsenic, As, results in
major environmental loads. In the following paragraphs, we briefly introduce
relevant information on ecotoxicity of the selected representatives—Hg and also
Cd, Pb, Cu.
27.6.6.1 Mercury
Hg is found in small concentrations in many rocks, and, therefore, certain natural
background levels can be detected in soils, air, and water around the world. Its
mining and industrial applications have increased significantly since the industrial
revolution. Other releases typically include waste incineration, coal combustion,
base metal smelting, chlor-alkali industry, small-scale gold mining, use in dental
amalgam as well as use in artisanal jewelry and trinkets for tourists in certain regions.
Mercury has been recognized as a serious threat within the UN Environment
Minamata Convention. It is known for its characteristic environmental fate that
includes formation of organo-mercury species (e.g., methyl Hg) by microorganisms
in abiotic conditions like sediments, which may easily enter the food chain and
become bioaccumulated. Moreover, they have also been shown more toxic than the
inorganic mercury. Some well-known effects in humans include neuropathies,
developmental disruptions (Minamata disease), or kidney problems. Invertebrates
display variable sensitivity, and concentrations as low as 0.04 μg/L were shown to
inhibit reproduction in Daphnia magna (Biesinger et al. 1982). For freshwater fish,
inorganic mercury is not as toxic as some other metals like Cu, Pg, Zn, or Cd with
96 h LC50 ranging in hundreds of μg/L (Table 27.3).
564
L. Bláha and J. Hofman