Heavy metal concentrations in the common benthic fishes caught from the coastal waters of eastern Taiwan


W.-B. Huang


People in Taiwan consume a large amount of marine fish, most of which are captured from the costal waters around Taiwan. Heavy metals are recognized as one of the most important pollutants, and their accumulations in the organisms have been studied and monitored for the safety of seafood consumption in the coastal waters of Taiwan; however, its regulation has been overlooked in the eastern region. This study evaluates the seafood consumption safety of the coastal fisheries in eastern Taiwan and establishes a baseline reference of the heavy metal levels in the fish of this region for the future monitoring of heavy metal pollution. Zinc, copper, cadmium and lead concentrations were determined in muscles, gills, intestines and livers of twenty benthic species of the most common commercial fish caught from the coastal waters of eastern Taiwan using a flame atomic absorption spectrometer. The results showed that zinc concentrations were the highest in the tissues, followed by copper and cadmium, and lead being the lowest except in the gills. Among the tissues, liver showed the highest metal concentrations, followed by intestine and gill, and was found to be the lowest in the muscle. The concentrations of zinc, copper, cadmium and lead in muscle ranged 2.0-6.2, 0.15-0.81, 0.02-0.12 and < 0.02-0.15 μg/g wet weight, respectively. The concentrations of the four elements in liver were in the range of 16.9-59.1, 1.4-12.4, 0.11-1.16 and < 0.02-1.09 μg/g wet weight, respectively. The concentrations of the heavy metals in the tissues varied significantly among species. Spottyback searobin Pterygotrigla hemistica and soldierfish Myripristis berndti contained in general higher concentrations of the metals in muscle and liver than other species of fish, respectively. The metal concentrations of fish found in this study are similar to the metal levels of the fish caught from slightly polluted waters in other parts of Taiwan, while the metal concentrations in our fish muscle are far below the consumption safety tolerance set by most countries in the world. Therefore, no public health problem would be raised from the consumption of fish from the coastal waters of eastern Taiwan.

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