In a study completed April 16, the Hong Kong Center for Food Safety detected high heavy metal content in several seafood species. The highest was found in the three alfonsino fish, ranging from 609 to 1,370 micrograms per kilogram (mg/kg), 509 to 1,010 mg of which are methylmercury, the organic form of mercury stored in the muscle of predatory fish.
Dr. Ho Yuk-yin, community medicine consultant of the center, announced that his team took 280 fish samples from 89 species. Samples were taken from local markets. Methylmercury contents from the samples ranged widely from 3 to 469 mg/kg of methylmercury.
Apart from alfonsino, species found to contain high mercury were yellowback sea bream and yellowtail barracuda. Canned albacore tuna also contained a lot of methylmercury, at 205 to 253 mg/kg, while other tuna species such as canned and fresh skipjack and canned yellowfin varied between 85 and 205 mg/kg.
Ho explained that methylmercury could harm the nervous system as well as slowing down cell development in fetuses. He warned that parents should closely monitor their children's diets and suggested that pregnant women, or those planning a pregnancy and young children should avoid consuming large predatory fish that contain high mercury levels.
