Organochlorine pesticides in seafood: occurrence and risk assessment

Organochlorine pesticides (OCPs) are semi volatile organic compounds of global concern. In the last decades, their distribution, sources, transformation, toxicity and accumulation in several ecosystems, especially the aquatic have gained attention. The seafood market has experienced a constant growth in the last century, being an important source of nutrients and energy worldwide. Hence, the beneficial effects of seafood consumption can be compromised by the adverse health effects induced by OCPs. Diet is the main source of chronic exposure to low doses of these substances. The chronic effects of OCPs from food intake on human health are not well defined, but there is increasing evidence of carcinogenicity and genotoxicity, as well as disruption of hormonal functions. High persistence in the environment and bioaccumulation potential are characteristics of OCP compounds. These characteristics associated with high fat content of seafood species, make this food sample a higher risk commodity. Despite regulatory bans or strict limits on usage being imposed on OCPs in most countries, these compounds continue to be detected in measurable amounts in the eco-system including marine life. Reliable analytical methods are required to determine OCPs in foods of marine origin. OCP residues detection methods for seafood samples comprise two key preparation steps prior to identification/quantification: extraction of target analytes from the bulk of the matrix, and partitioning of the residues in an immiscible solvent and/or clean-up of analytes from matrix co-extractives, especially fat which interferes with assays. Recent analytical developments have attempted to minimize the number of physical and chemical manipulations, the solvent volumes, the number of solvent evaporation steps, the use of toxic solvent and have aimed to automate the extraction and clean-up procedures as far as possible. Following the extraction/purification procedures, OCPs are separated in gas chromatography analysis, and then identified and quantified using different kinds of detection methods. In this chapter, relevant issues regarding OCPs will be discussed, such as, biological activity, an overview of levels found in seafood worldwide and analytical determination from 2004 to present. The advantages and drawbacks of the analytical methods developed recently and most used will be presented and commented based on our expertise related to sample preparation techniques and chromatographic methods. For risk assessment, the OCPs concentration data from existing studies performed will be considered. Moreover, the risk quotients for carcinogenicity and acute toxicity will be described.