1989-2010年广东沿海牡蛎体镉含量时空分布特征及其健康风险评价

Spatial-temporal trends of cadmium in oyster along Guangdong coastal waters from 1989 to 2010 and their risks on human health

为评价广东沿海牡蛎体镉（Cd）含量的时空分布特征及其食用健康风险,实验根据2001—2010年广东17个海湾的牡蛎体Cd含量监测结果及1989—1999年的历史数据,分析了广东沿海总体及粤东、珠江口、粤西3大海区牡蛎体镉含量的时空分布特征;并采用风险商法评价其健康风险。1989—2010年广东沿海累计268频次的监测结果表明：牡蛎体Cd含量变化范围为未检出~10.80 mg/kg（均值1.14 mg/kg,以湿重表示,下同）,检出率97.01%;其中98.64%符合中国、美国牡蛎体或贝类的Cd含量限量标准（≤4 mg/kg）。珠江口海域达标率为三大海域最低（86.5%）,是今后生物监测与海洋环境管理的重点。2001—2010年牡蛎体Cd含量的健康风险依次为儿童-青少年（5~17岁）〉老年人（60岁以上）〉成年人（18~59岁）;连续食用广东沿海牡蛎10年,其Cd含量在70年内不会对人体构成Cd摄入过量的风险。

The coastal ecosystem has been threatened by increasing heavy metals pollution, so the timely health risk assessments of biological indicators oysters are of importance to both the sustainable development of coastal oysters culturing industry and consumers＇ health. This paper analyzed the spatial-temporal trends of Cd content in oyster soft tissues from 17 main Guandong coastal bays/estuaries from 1989 to 2010 and assessed their health risks on groups of consumers by their dietary compositions and ages. Results of total 268 samples showed that the concentration of Cd varied between not detected （nd） and 10.80 mg/kg wet weight with average of 1.14 mg/kg wet weight; of which, 98.64% of samples did not exceed the threshold of upper levels （4 mg/kg） established by Ministry of Agriculture, China and EPA, USA. The Pearl River estuary should be the Priority of Mussel Watch and environmental management considering its highest Cd content and large variance in oysters soft tissues there. The order of risks on consumers＇ health was the younger （aged 5 to 17） 〉 the elder （aged 60 or above） 〉 the adults（aged 18 to 59） in sequence, while the Hazard quotient （HQ） was less than 1 for oysters edible soft tissues from Guangdong coastal waters, indicating that the intake of Cd by oyster consuming had not exceeded the oral Reference Dose.