俚岛湾海域砷的分布特征及污染评价

Distribution Characteristics and Contamination Assessment of Arsenic in Lidao Bay

以威海俚岛湾养殖区为研究对象，调查研究了俚岛湾海域表层海水和沉积物中总砷的分布特征，并综合评价了砷的污染状况及潜在生态风险。俚岛湾海域表层海水总砷浓度为1.78-2.78μg/L，平均浓度为2.20μg/L，比大洋水略高，俚岛湾海域海水水质较好，未受到砷污染；海水中砷的季节变化为夏季较高、秋冬季基本稳定、春季最低。俚岛湾海域表层沉积物中砷的平面分布呈现出由近岸向远岸降低的趋势，砷含量的年际变化甚微，基本保持稳定的水平；采用潜在生态风险指数法和重金属质量基准法对沉积物进行评价。评价结果表明，该海域表层沉积物中砷污染水平较低，属于低潜在生态风险。

Distribution characteristics of arsenic in surface seawaters and sediments were studied in Lidao aquicultural area, and pollution level and potential ecological risk of arsenic was evaluated. Results showed that the arsenic concentrations of surface seawaters in Lidao bay was between 1. 78-2. 78 μg/L, with mean of 2. 20 μg/L. The arsenic concentrations of seawater in Lidao bay was a little higher than oceanic water, so the seawater was not affected by arsenic;The concentrations of arsenic in seawater vary with seasons, higher in summer while lower in spring, basically stable in fall and winter. The distributions of arsenic in sediments were decreased with the distance off the coast. The interannual variability of arsenic basically remained stable. The arsenic pollution level of sediments was evaluated by Potential Ecological Risk Index and Sediment Quality Guidelines. Results showed that the arsenic pollution and its potential ecological risk were lower in surface sediment in Lidao bay.