长江口外围重要港区及邻近海域沉积物中有机锡分布特征及生态风险评价

为全面了解长江口外围重要港区及邻近海域沉积物中有机锡(OTCs)污染状况，主要选取长江口外围重要港区及邻近海域共29个点的表层沉积物，分析其OTCs含量并进行生态风险评价. 使用气相色谱-三重四级杆串联质谱仪(GC-MS/MS)对沉积物中三丁基锡(TBT)、二丁基锡(DBT)、一丁基锡(MBT)、三苯基锡(TPhT)、二苯基锡(DPhT)、一苯基锡(MPhT)共6种OTCs化合物的含量进行测定，结果表明:①MBT、DBT、TBT、MPhT、DPhT和TPhT在长江口外围重要港区及邻近海域均被检出，其含量(以干质量计、以锡离子计)范围分别为nd (未检出)~16 ng/g、nd~7.8 ng/g、nd~2.6 ng/g、nd~1.0 ng/g、nd~2.3 ng/g、nd~3.3 ng/g，检出频率分别为82.8%、48.3%、6.9%、41.4%、75.9%、72.4%. ②空间分布总体呈离海岸港口越近OTCs污染越严重的趋势，部分渔业活动频繁区域OTCs污染相对较高且TBT、TPhT可能存在新近输入. 与其他地区相比，该研究区域OTCs整体污染水平较低且主要来源于历史残留和沿岸发达地区的污水输入. ③生态风险评价表明，虽然长江口外围重要港区及邻近海域整体OTCs污染风险水平较低，但根据荷兰国家海岸与海洋管理研究所(RIKZ)提出的《沿海海洋沉积物质量指南》，TBT和TPhT的最大允许浓度分别为0.7和1.0 ng/g，仅个别位点超过最大允许浓度，且均出现在渔业活动频繁区域. 研究显示，长江口外围重要港区及邻近海域总体OTCs含量和生态风险均处于较低水平，但对于某些TBT、TPhT的新近输入区域应持续关注. 

Distribution Characteristics and Ecological Risk Assessment of Organotin in Sediments in Important Harbor Areas and Adjacent Sea Areas in Periphery of Yangtze Estuary

In order to fully understand the pollution of organotin in the sediments of important port areas and adjacent sea areas on the periphery of the Yangtze Estuary, organotin concentration on the surface sediment of 29 sites in this areas was analyzed and ecological risk in the area was assessed. A gas-phase triple quadrupole tandem mass spectrometer (GC-MS/MS) was used to determine the concentration of six organotin compounds, including tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT). The results showed that MBT, DBT, TBT, MPHT, DPHT and TPHT were all detected in important harbor areas and adjacent sea areas in the periphery of the Yangtze Estuary, ranging from nd-16 ng/g, nd-7.8 ng/g, nd-2.6 ng/g, nd-1.0 ng/g, nd-2.3 ng/g, nd-3.3 ng/g, respectively. Their detection frequencies were 82.8%, 48.3%, 6.9%, 41.4%, 75.9% and 72.4%, respectively. The spatial distribution of organotin generally showed a trend of higher concentrations closer to the port. The concentrations of organotin were relatively high in areas with frequent fishery activities, and TBT and TPhT were recently introduced. Compared with other regions, the levels of organotin concentration in this area were relatively lower, mainly from history residues and the sewage input from developed coastal areas. The ecological risk assessment results showed that the ecological risks of organotin in the studied sea area were at a low relatively level. However, according to the coastal marine Sediments Quality Guidelines (SQG) of the Netherlands National Institute for Coastal and Marine Management (RIKZ), the maximum permissible concentrations (MPC) of TBT and TPhT are 0.7 and 1.0 ng/g, respectively. Only a few sites had concentrations that exceeded the maximum allowable concentration, and they all occurred in the areas with frequent fishing activities. The studies have shown that the overall organotin content and ecological risks in important harbor areas and adjacent sea areas in the periphery of the Yangtze Estuary are at a relatively low level, but the recent input of TBT and TPhT in some areas still requires continuous attention.