淮南城区小学校园及其临近街道地表灰尘中汞的分布特征及污染评价

在淮南市区40个小学采集楼道、操场及学校临近街道灰尘样品.通过王水水浴-冷原子荧光法测定汞含量,地累积指数法评价其汞污染状况,健康风险模型评估其对儿童的健康风险.结果显示:小学校园及临近街道灰尘中汞含量呈现出:楼道操场街道,分别为0.329、0.164、0.118mg·kg~(-1),各介质中均出现了不同程度汞积累.对于不同功能区,街道灰尘汞呈现出:农业区商业交通区煤矿区废弃煤矿区旅游区;操场灰尘中汞表现为:废弃煤矿区商业交通区旅游区煤矿区农业区;楼道灰尘中汞表现为:商业交通区旅游区煤矿区废弃煤矿区农业区.淮南市燃煤活动对淮南城区小学校园操场和楼道灰尘汞的积累影响较大;从健康风险上而言,灰尘中汞对儿童无显著的非致癌风险,但商业交通区内小学楼道内灰尘汞的暴露量较高,可能会危害儿童健康,需加以重视.

Concentrations and pollution assessment of mercury in surfaces dust at urban streets and elementary school campuses of Huainan City

The present study aims at assessing mercury (Hg) spatial distribution, pollution status and exposure risk to the health of children in the surface dust at primary school campuses and their surrounding streets in Huainan City. Totally 120 dust samples were collected from campus playgrounds, corridors, and their adjacent streets. Determination of mercury was conducted by using the method of HCl-HNO₃ digestion and cold vapor atomic dust fluorescence. Geo-accumulation index was then used to evaluate mercury pollution levels. The pollution of mercury was evaluated for the health risk of children by a health risk assessment model. The result suggested that the concentrations of mercury in the surface dust were 0.329, 0.164 and 0.118 mg·kg^-1 in the corridor, playground and street, respectively. Different degrees of mercury accumulation existed in different media in Huainan. Mercury contents in streets dust from different functional areas were in the order of agricultural area > business-traffic area > coal mining area > abandoned coal mine area> tourist area, those in playgrounds dust were abandoned coal mine area > business-traffic area > tourism area > coal mining area> agricultural area, while those in corridors dust were business-traffic area > tourist area > coal mining area > abandoned coal mine area > agricultural area. Coal combustion had a great influence on mercury accumulation in the dust of urban primary school campus playground and corridor of Huainan. In terms of health risks, mercury in the dust had no significant non-carcinogenic risk to children. However, the risk index of mercury in campus dust from business-traffic area was higher, and more attention should be paid to it.