Seafoods and Environmental Contaminants

Abstract

Seafood is one of the major sources of protein and functional components that are crucial to human health and is an important part of the diet in many countries. On the other hand, seafood usually contains residues of persistent environmental pollutants (PEPs), such as organohalogen compounds: polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs) namely dioxins, polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), and heavy metals (mercury-Hg, arsenic-As, cadmium-Cd, and lead-Pb). Dietary intake is the major contributor of human exposure to these contaminants and seafood has the greatest risk due to its high lipid content. These lipophilic chemicals accumulate in fatty tissues of marine organisms and are subsequently transferred to humans through the food chain, damaging ecosystems and human health.PEPs in seafood have gained special attention from consumers, scientists, and environmental and governmental organizations due to their widespread consumption. Several studies have determined PEPs in aquatic organisms from freshwater and marine environments. Beside the marine ecosystem, products from aquaculture are also associated with increased risk of contamination by these pollutants, as well as antibiotic residues. This chapter discusses the wide range of studies on seafood contaminants and the factors behind the contamination. Furthermore, regulations for these contaminants and recommendations to reduce the risk of contamination are provided. Persistent environmental pollutants (PEPs) Organohalogen compounds (OCs)OCs is a group of chemically stable, carbon-based, and ubiquitous compounds characterized by low volatility and high lipid solubility. They are formed mainly through combustion, waste incineration, metal recycling and refining, chemical manufacturing, biological, and Handbook of Seafood Q uality, Safety and Health ApplicationsEdited by Cesarettin Alasalvar, Fereidoon Shahidi, Kazuo Miyashita and Udaya Wanasundara

QSPR-based estimation of the half-lives for polychlorinated biphenyl congeners

“…These contaminants do not readily break down, and therefore may remain in the environment for a long period, be transported long distances and distributed in air, water, and soil by reason of their persistence, hydrophobicity and inertness [3,4]. Immobilization of PCBs in the sediments of marine environments causes these pollutants to be released slowly over a long duration [5], and they accumulate in the fatty tissues of aquatic living organisms (such as fish, shellfish and seals) on account of their lipophilicity; they are subsequently transferred to humans through the food chain, which exposes seafood consumers to a serious threat [6]. Degradation of chemicals in the environment, which is usually characterized by a reaction rate constant or half-life ðt 1=2 Þ, occurs through processes such as photolysis, hydrolysis, oxidation and biodegradation [7].…”