| Mercury is a highly toxic, persistent and bioaccumulative trace element that is now exits in various environment media and food worldwide. Adversely may be taking place at lower concentrations than previously thought. All forms mercury is all experiencing the circulation of atmosphere with interacting transforming and transporting and ultimate entering waterbody or land ecosystem. In waterbody or land ecosystem, deposition is one of mainly source of toxic substance. It is direct connection in aquatic ecosystem that methyl mercury content in fish body and atmospherec deposition mercury. Atmospheric wet deposition mercury is the primary type at region that have much rainy days and precipitation. Now, wet deposition mercury has been much researched in abroad. China has been considered as the country where mercury emission ranks a maximum. The research is sporadic job in Beijing, Guizhou, Changbai mountain. Shanghai located in southeast in the Yangtze River delta, have large population density and economic activity intensity. The simulation shows that there is the maximum at wet deposition mercury concentration and flue over the world. Shanghai located in typical East Asia monsoon impacting area, where there exits existence seasonal transition for winter monsoon and summer monsoon, southwest monsoon and southeast monsoon interaction control in summer monsoon. Then this bring seasonal characteristic change of atmospheric vapour source and mercury inputs. Shanghai is at the border belt of sea and ground. Aerosol component change are observably. There are continent inland fine sand fling up in the air the aerosol, the aerosol discharging by human being and baysalt aerosol coming from ocean, variable aerosol constituent help atmospheric mercury interacts, transforms at reaction interface.Wet depositon sample were collected at urban, suburban, steel industrial park, chemistry industrial park and coast agricultural region, sum deposition sample at urban and suburdan in Shanghai. Concentrations of ions, mercury and others elements were measured, and analysis space-time distribution characteristic, and mercury source has been proved by statistivs analyzing, air current trajectory model and isotope analysis, at last analysis the mercury damage on the human. Research distribution and source of atmospheric wet depositon mercury in shore city has importance therefore.Following results have been acquired:(1) Wet deposition mercury concentration and fluxes are higher in Shanghai. Wet depositon total mercury volume weighted average concentration at urban, suburban, steel industrial park, chemistry industrial park and coast agricultural region respectively is 0.33μg·L-1 (change range from 0.06μg·L-1 to 1.18μg·L-1),0.23μg·L-1, 0.26μg·L-1, 0.24μg·L-1 and 0.29μg·L-1, ratio of particle mercury accounted for the total mercury of 48.5%,57.0%,50.0%,62.2% and 64.2% concentrationrespectively, total mercury fluxes respectively is 447.67μg·m-2·y-1,233.55μg·m-2·y-1,284.46μg·m-2·y-1, 296.97μg·m-2·y-1 and 296.97μg·m-2·y-1, variation pattern of total mercury respectively is summer=winter>autumn>spring, autumn>winter>summer=spring, autumn=winter> spring>summer, autumn>winter>spring>summer, autumn>spring>winter>summer. Particle mercury concentration is enhancement and dissolve mercury concentration is reduce when API index increas. The correlation of wet deposition concentration and precipitation is unconspicuous, and they are positive correlation of total mercury concentration and precipitation. Wash under cloud take contribution over 40.9% in wet depositon tatal mercury concentration, local contaminant is one of major source in wet deposition mercury.(2) Total depositon total mercury volume weighted average concentration is 0.51μg·L-1 at urban, and total mercury fluxes is 654.42μg·m-2·y-1, give first place to wet settlement, and the multisource source of matter obviously. Total mercury average concentration is 0.46μg·L-1 at suburban, and total mercury fluxes is 466.77μg·m-2·y-1, dry depositon conruibute half in total depositon, and sea source devoted largly in total depositon at suburban. Total mercury concentration is maximum in summer at urban and suburban, different that of wet depositon obviously. The source of dry deposition have difference, in witer season, north-west is mostly and low temperature and dry, mercury concentration lowly for Hg0 has been adsorbed from aerosol lessly. In summer season, sea salt particles priority to aerosol from south-east. It can add mercury deposition in summer for Hg0 has been adsorbed from aerosol easily in humid and high temperature weather.(3) Every ions concentration in wet deposition are higher, total ions at suburban (847.60μeq·L-1) more than other functional zone (change range from 383.88μeq·L-1 to 437.92μeq·L-1). Ions volume weighted average concentration from higher to lower respectively is SO42->Ca2+>NH4+>Cl>NO3->Na+>Mg2+>F->K+,the sum concentration of SO42- and Ca2+ accounted for the total ions concentration of 49.77%. Temporal variation pattern of ion Na+ is winter>autumn>spring>summer, NH4+ is spring>autumn>winter>summer, the others ions are autumn>winter>spring>summer. Ions source is complicated and multisource obvious, ions concentration were large affected by artificial disturbance and 76.7% of ions concentration is source form artificial disturbance. In ions, K+, Mg2+ was mostly from land source, and Na+, Cl" was mostly from sea source, and 42.4% of Cl- was anthropogenic source. Ca2+, NH4+, SO42-, NO3- and F" were mostly from anthropogenic source. The concentration of ions in every functional zone exists difference obviously, but the ratio of each ion accounted for the total ions concentration less.(4) It have different source of the mercury and other elements were identified by correlation and principal component factor analysis. Mercury source part from dust of surface and building, and part from special sources at urban, earthcrust and special at suburban, fossil fuel burning and dust of surface and building and special at steel industrial park, dust of surface and building and special at chemistry industrial park, special source at coast agricultural region.(5) Source of vapour and low altitude air mass exist difference obviously at all seasons. At vapoure source, no mainly directivity in spring, North-west was mainly in autumn, North-west was mainly in summer and winter. At low altitude air mass, North-east was mainly directivity in summer, and North-east was mainly in the other seasons.The wet deposition total mercury concentration was obviously influenced by vapour source. Wet depositon mercury concentration that vapour source from sea higher than what from land and particle mercury accounted for the total mercury oppositioned, for higher temperature and higher fluxes of the air-water mercury exchange quantities and Hg0 ready-made Hg2+ easy to be oxidized foe Hg0 chelated with halogen elements. Mercury concentration that vapour source from land with relatively long migration distance higher than that from relatively near sea or relatively shorter migration distance, and particle mercury concentration accounted for the total mercury to reduced, for absorption or dissolved aerosol ions and trace element, local air mercury enter into rain cloud on land more than on sea when vapour evaporation at seasons except for summer. Wet deposition speciation was obviously influenced by low altitude air mass source. Particle mercury concentration accounted for the total mercury that low altitude air mass source from sea lower than land, and total mercury concentration increased when relatively long migration distance at same time and low altitude air mass source from same direction.Total mercury concentration was influenced by rainy days and precipitation. Wash under cloud take more contribution in mercury concentration when little precipitation. Mercury concentration was influenced by weather conditions the other day because low altitude aerosol interrelated with weather conditions.(6)Isotopeδ18O ranges from-12.16‰to-3.00‰with season and annual average was-8.11‰at urban. spring, summer, autumn and winter season average respectively-5.58‰,-10.35‰,-7.45‰and-4.09‰at urban. Ranges from-10.66‰to+1.87‰with season and annual average was-5.16‰. Isotopeδ18O variation character was higer at spring and witer, lower at summer and autumn. Isotopeδ18O was negatively correlated with temperature, the line is fitted asδ18O=-0.20T-2.73. the precipitation effect ofδ18O in the precipitation is very pronounced, the line is fitted asδ18O=-0.0603H-3.1841 (H is precipitation)。The wet deposition total mercury concentration has effected by precipitation that have homology vapour source and transporting before getting to Shanghai. Total mercury concentration and 18O have been reduced when precipitation generous. Be contrary on the contrary. Wet deposition mercury concentration has been effected by mercury of vapour carry-over. Mercury concentration in cloud has decreased at latter atage precipitation for mercury fall off prederential during the period of rain as heavy isotope. Total mercury concentration has been effected by precipitation when vapour source and transporting and precipitation before getting to Shanghai for mercury capacity of vapour carry-over homology.(7)Wet deposition mercury concentration was controlled prominently by vapour source and transportation ways especially migration distance at same time. Total mercury concentration affected by precipitation before the time when the wet deposition happen on Shanghai in different wet deposition that have same vapour source and transportation ways. Isotopeδ18O and total mercury concentration to reduced when much precipitation happened before the cloud reached Shanghai for mercury as weightly isotope precedence fall when wet deposition happen lead to mercury concentration decrease in cloud.(8) Each functional zone wet deposition mercury concentration higher than 0.1μg·L-1, sample was estimated by the method of Potential Ecological Risk Index and the earth's surface waterⅢkind standardwas chose as the estimated standard, the result show that wet deposition mercury was heavy degree ecological risk, and few month was significantly heavy degree ecologicl risk. Sample health risks associated with mercury in drinking water was estimated by Health Risks Associated Models, the result show that wet depositon mercury health risk more than drinking water region in Shangh and other areas and the highest risk at urban and lowest at suburban.
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