298
5.4.1.3 Lead (Pb)
Lead is a ubiquitous and typical toxic contaminant released into the environment
from natural and anthropogenic sources. However, the environment has been
enriched by industrial processes, and man-made sources such as mining, industries,
motor vehicle exhaust and batteries (Yingliang et al. 2014). Mining and smelting,
soldering, battery manufacturing, ammunition, metal water pipes, paint and petrol
are reported as anthropogenic sources. Pb occurs in the environment both organic
and inorganic forms, organic lead is the most toxic lead form (Tamele and Loureiro
2020). Lead levels of Indian white prawn (Fenneropenaeus indicus) and blue crab
(Portunus pelagicus) obtained from Tok Bali Port in Kelantan, Malaysia were determined as 0.008 μg/g and 0.015 μg/g respectively (Salam et al. 2019). Mok et al.
(2014) determined heavy metal concentrations of some molluscs, crustaceans and
cephalopods collected from major fish markets on the coast of Korea. Lead concentration was found to be 0.117 μg/g in oyster, 0.154 μg/g in mussel, 0.018 μg/g in bay
scallop, 0.007 μg/g in Japanese flying squid, 0.021 μg/g in small octopus, 0.012 μg/g
in snow crab and 0.007 μg/g in blue crab. They reported that these values are lower
than the regulatory limits set by various countries. In a study investigating seasonally heavy metal concentrations of cultured oysters (Crassostrea gigas) in coast of
the Gulf of California, in the state of Sinaloa, Mexico, the highest Pb concentration
was found to be 3.46 mg/g in April (Gongora-Gomez et al. 2017).
It is reported that oysters can accumulate very high levels in zinc (Zn) and copper
(Cu) in their tissues (Rainbow and Phillips 1993).
5.4.1.4 Zinc (Zn)
Zinc, which is a trace element in sea water, plays an important role in biological
events. High zinc concentration in marine environments is parallel to human activities and urbanization, and can be caused by paint industry, mining, electro-coating,
and synthetic fibre production. Zinc is one of the most ubiquitous and mobile among
the heavy metals and is transported in natural waters in both dissolved forms and is
associated with suspended particles. In seawater, much of the zinc is found to be in
the dissolved form as inorganic and organic complexes (Dhinamala et al. 2017). In
various studies examining heavy metal concentrations in shellfish, the highest concentration among the studied metals was determined in zinc. Some of them are
shrimp (Penaeus monodon) (Hashmi et al. 2002; Meshram et al. 2014; Dhinamala
et al. 2017), miscellaneous shrimp and crab species (Krishnamurti and Nair 1999),
oyster (Crassostrea virginica) (Vazquez et al. 1995) and Pincdata radiata (Gokoglu
et al. 2006).
5 Shellfish Safety
5.4.1.3 Lead (Pb)
Lead is a ubiquitous and typical toxic contaminant released into the environment
from natural and anthropogenic sources. However, the environment has been
enriched by industrial processes, and man-made sources such as mining, industries,
motor vehicle exhaust and batteries (Yingliang et al. 2014). Mining and smelting,
soldering, battery manufacturing, ammunition, metal water pipes, paint and petrol
are reported as anthropogenic sources. Pb occurs in the environment both organic
and inorganic forms, organic lead is the most toxic lead form (Tamele and Loureiro
2020). Lead levels of Indian white prawn (Fenneropenaeus indicus) and blue crab
(Portunus pelagicus) obtained from Tok Bali Port in Kelantan, Malaysia were determined as 0.008 μg/g and 0.015 μg/g respectively (Salam et al. 2019). Mok et al.
(2014) determined heavy metal concentrations of some molluscs, crustaceans and
cephalopods collected from major fish markets on the coast of Korea. Lead concentration was found to be 0.117 μg/g in oyster, 0.154 μg/g in mussel, 0.018 μg/g in bay
scallop, 0.007 μg/g in Japanese flying squid, 0.021 μg/g in small octopus, 0.012 μg/g
in snow crab and 0.007 μg/g in blue crab. They reported that these values are lower
than the regulatory limits set by various countries. In a study investigating seasonally heavy metal concentrations of cultured oysters (Crassostrea gigas) in coast of
the Gulf of California, in the state of Sinaloa, Mexico, the highest Pb concentration
was found to be 3.46 mg/g in April (Gongora-Gomez et al. 2017).
It is reported that oysters can accumulate very high levels in zinc (Zn) and copper
(Cu) in their tissues (Rainbow and Phillips 1993).
5.4.1.4 Zinc (Zn)
Zinc, which is a trace element in sea water, plays an important role in biological
events. High zinc concentration in marine environments is parallel to human activities and urbanization, and can be caused by paint industry, mining, electro-coating,
and synthetic fibre production. Zinc is one of the most ubiquitous and mobile among
the heavy metals and is transported in natural waters in both dissolved forms and is
associated with suspended particles. In seawater, much of the zinc is found to be in
the dissolved form as inorganic and organic complexes (Dhinamala et al. 2017). In
various studies examining heavy metal concentrations in shellfish, the highest concentration among the studied metals was determined in zinc. Some of them are
shrimp (Penaeus monodon) (Hashmi et al. 2002; Meshram et al. 2014; Dhinamala
et al. 2017), miscellaneous shrimp and crab species (Krishnamurti and Nair 1999),
oyster (Crassostrea virginica) (Vazquez et al. 1995) and Pincdata radiata (Gokoglu
et al. 2006).
5 Shellfish Safety