297
viridis, Crassostrea gigas, Meretrix lyrata and Amusium pleuronectes) captured
from the northern shores of Central Java (Indonesia), while the highest Cd concentration was found in Amusium pleuronectes the lowest was in Perna viridis (Yulianto
et al. 2005). Cadmium levels of Indian white prawn (Fenneropenaeus indicus) and
blue crab (Portunus pelagicus) obtained from Tok Bali Port in Kelantan, Malaysia
were determined as 0.04 μg/g and 0.09 μg/g respectively (Salam et al. 2019).
5.4.1.2 Mercury (Hg)
Mercury is a toxic heavy metal released into the environment from both natural and
anthropogenic sources. It is of great interest to consumers as to whether it can cause
neurological effects at low dose levels. Mercury is distributed throughout the world,
and cycles naturally through the earth’s crust, atmosphere, oceans, and life forms,
with trace amounts in fish, plants, and animals. Human activity increases the amount
of mercury emitted into water, air, and soil, through coal-combustion (used to power
utility plants); mining; waste disposal; preparation of fungicide seed dressings in
agriculture; and chlor/alkali plants. Mercury is used in products such as batteries,
vapor discharge lamps, fluorescent bulbs, switches, and thermometers. Many of
these products end up in landfills or incinerators. Mercury enters the food chain
with the help of aquatic microorganisms. Released into the environment in inorganic form, mercury is methylated by bacteria in water and converted to an organic
form, usually methylmercury (Hellberg et al. 2005).
Mercury levels were measured in commercially crustacea caught from the
Central Adriatic and Tyrrhenian coasts of Italy and differences in mercury levels
were determined between species. The lowest levels of mercury were detected in
shallow aquatic decapods, karamote shrimp (Penaeus kerathurus), wart crab
(Eriphia verrucosa) and European spider crab (Maja squinado). Deepwater rose
shrimp (Parapenaeus longirostris), blue and red shrimp (Aristeus antennatus) and
Norway lobster (Nephrops norvegicus), which are in close contact with the bottom
sediments, have been reported to exceed the limit values set by the European commission (Di Lena et al. 2018). Mercury levels of eight bivalve species collected
from a local market in Poland were examined. For this purpose Dog cockle
(Glycymeris glycymeris), manila clam (Ruditapes philippinarum), Atlantic jackknife clam (Ensis directus), blue mussel (Mytilus edulis), Pacific oyster (Crassostrea
gigas), great scallop (Pecten maximus), common cockle (Cardium edule), and hard
clam (Mercenaria mercenaria) were collected. Mercury concentrations were determined between 0.033–0.577 (mg/kg dry matter) in these selected bivalve species
and the average highest mercury level was found in Pacific oyster (Szkoda et al.
2015). In a study examining mercury concentrations in eight cephalopod species
purchased from the major fish landing ports and wet markets on the Peninsular
Malaysia, mercury concentrations were determined as 0.099–715 mg/kg DW in
squids, 0.233–0.486 mg/kg DW in cuttlefishes and 0.208 mg/kg DW in octopus
(Ahmad et al. 2015).
5.4 Chemical Contaminants
viridis, Crassostrea gigas, Meretrix lyrata and Amusium pleuronectes) captured
from the northern shores of Central Java (Indonesia), while the highest Cd concentration was found in Amusium pleuronectes the lowest was in Perna viridis (Yulianto
et al. 2005). Cadmium levels of Indian white prawn (Fenneropenaeus indicus) and
blue crab (Portunus pelagicus) obtained from Tok Bali Port in Kelantan, Malaysia
were determined as 0.04 μg/g and 0.09 μg/g respectively (Salam et al. 2019).
5.4.1.2 Mercury (Hg)
Mercury is a toxic heavy metal released into the environment from both natural and
anthropogenic sources. It is of great interest to consumers as to whether it can cause
neurological effects at low dose levels. Mercury is distributed throughout the world,
and cycles naturally through the earth’s crust, atmosphere, oceans, and life forms,
with trace amounts in fish, plants, and animals. Human activity increases the amount
of mercury emitted into water, air, and soil, through coal-combustion (used to power
utility plants); mining; waste disposal; preparation of fungicide seed dressings in
agriculture; and chlor/alkali plants. Mercury is used in products such as batteries,
vapor discharge lamps, fluorescent bulbs, switches, and thermometers. Many of
these products end up in landfills or incinerators. Mercury enters the food chain
with the help of aquatic microorganisms. Released into the environment in inorganic form, mercury is methylated by bacteria in water and converted to an organic
form, usually methylmercury (Hellberg et al. 2005).
Mercury levels were measured in commercially crustacea caught from the
Central Adriatic and Tyrrhenian coasts of Italy and differences in mercury levels
were determined between species. The lowest levels of mercury were detected in
shallow aquatic decapods, karamote shrimp (Penaeus kerathurus), wart crab
(Eriphia verrucosa) and European spider crab (Maja squinado). Deepwater rose
shrimp (Parapenaeus longirostris), blue and red shrimp (Aristeus antennatus) and
Norway lobster (Nephrops norvegicus), which are in close contact with the bottom
sediments, have been reported to exceed the limit values set by the European commission (Di Lena et al. 2018). Mercury levels of eight bivalve species collected
from a local market in Poland were examined. For this purpose Dog cockle
(Glycymeris glycymeris), manila clam (Ruditapes philippinarum), Atlantic jackknife clam (Ensis directus), blue mussel (Mytilus edulis), Pacific oyster (Crassostrea
gigas), great scallop (Pecten maximus), common cockle (Cardium edule), and hard
clam (Mercenaria mercenaria) were collected. Mercury concentrations were determined between 0.033–0.577 (mg/kg dry matter) in these selected bivalve species
and the average highest mercury level was found in Pacific oyster (Szkoda et al.
2015). In a study examining mercury concentrations in eight cephalopod species
purchased from the major fish landing ports and wet markets on the Peninsular
Malaysia, mercury concentrations were determined as 0.099–715 mg/kg DW in
squids, 0.233–0.486 mg/kg DW in cuttlefishes and 0.208 mg/kg DW in octopus
(Ahmad et al. 2015).
5.4 Chemical Contaminants