Organochlorines in Hong Kong fish

Muscle samples from 15 species of fish (n = 1) purchased from markets in Ho ng Kong and 10 liver samples of tilapia (Tilapia mossambica) collected from the Shing Mun River were analysed for organochlorines (polychlorinated bip henyls, Sigma DDTs, hexachlorobenzene, hexachlorocyclohexanes, chlordanes, mires and dieldrin), Polychlorinated biphenyls (PCBs) were detected in 15 m arket fish samples but the levels were very low (around 1 ng g(-1)). PCB le vels in tilapia livers collected from Tai Wai (29.3-65.1 ng g(-1)) were hig her than those from Fo Tan (3.5-23.2 ng g(-1)) suggesting that there may be some local point soucres. Sigma DDTs were detected in all samples, ranging from 3.3 to 75.6 ng g(-1) in the market fish and from 7.1 to 88.8 ng g(-1) in tilapia. The DDE/DDT ratios in the market fish (0.12-0.75) showed highe r variability than those of tilapia (0.30-0.46), suggesting that some of th e market fish may have been collected from areas where DDT was recently use d. Results of this preliminary study shaw that organochlorine levels in Hon g Kong market fish are low and do not cause any concern for human consumpti on. An on-going monitoring program, however, is recommended. (C) 1999 Elsev ier Science Ltd. All rights reserved.