Spatial Variation in Contaminant Occurrence in Marine Fishes and Prawns from Coastal Tanzania
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Date
2022
Journal Title
Journal ISSN
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Publisher
Environmental Toxicology and Chemistry
Abstract
There are limited data on organic contaminants in marine biota from coastal Tanzania, especially on the occurrence of
industrial‐use contaminants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The present
study, performed in 2018–2019 in coastal Tanzania and Zanzibar Island, aimed at assessing spatial variation in the occurrence of
PCBs; brominated flame retardants (BFRs), including PBDEs; and organochlorine pesticides, including dichlorodiphenyltri-
chloroethane (DDT), among three locations that differ in degree of anthropogenic activity. Analyzed samples included edible
tissues of marine fishes and prawns representing different trophic levels and habitats. The results indicate a mainland–island
difference, with fishes and prawns collected on Zanzibar having significantly lower PCB and DDT concentrations but higher
concentrations of hexachlorobenzene compared to the two mainland locations. The highest contaminant concentrations were
found in fishes and prawns collected around central Dar es Salaam harbor, with median ΣPCBs ranging from 22.3 to 577 ng/g
lipid weight and ΣDDTs from 22.7 to 501 ng/g lipid weight, suggesting local sources. Concentrations of PBDEs were similar
among locations, suggesting more diffuse sources. None of the “newer‐type” BFRs, including compounds introduced as
replacements for PBDEs, were detected in the present study. Stable isotope values of carbon (δ13C) and nitrogen (δ15N) varied
among locations, and the relationship between contaminants and δ15N varied among locations and habitat (pelagic/demersal).
Concentrations measured in the present study are below European guidelines for human consumption of fishes and prawns.
However, industrial‐use contaminants should be monitored in developing countries because they are contaminants of emerging
concern as a result of increasing industrialization and global trade of used products and wastes. Environ Toxicol Chem
2022;41:321–333. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf
of SETAC
Description
This research article was published by Environmental Toxicology and Chemistry in 2022