Atmospheric deposition of metals to coastal waters (Long Island Sound, New York USA): Evidence from saltmarsh deposits
Atmospheric deposition of metals to coastal waters (Long Island Sound, New York USA): Evidence from saltmarsh deposits
复制标题
DOI：
10.1006/ecss.1997.0299
复制
发表时间：
1998-04-01
影响因子：
2.8
通讯作者：
Dere, C
中科院分区：
文献类型：
--
作者：
Cochran, JK;Hirschberg, DJ;Dere, C
沉积年代学的六个高盐沼核心收集在纽约市和长岛，纽约，使用过量铅-210确定，表明，吸积率范围从0.1到0.4厘米年（-1）。平均而言，沼泽的增长幅度大约是该地区平均海平面上升幅度的两倍。沼泽中过量的Pb-210含量平均为31 +/- 14 dpm cm（-2），与Pb-210大气沉积的预期值相当。Cs-137和过量的Pd，Cu，Zn和Cd（定义为在核心的深度超过人类活动前的背景值）的通量的年表表明Cs-137和Cd在沼泽核心显着的迁移。铅在1970年和1980年之间显示出最大通量，与美国含铅汽油消费的历史记录一致。铜显示最近六个地点中有四个的通量减少，锌显示出可变模式。Pb、Cu和Zn的通量一般小于或等于直接测量的这些金属的大气通量，表明大气供应的重要性。假设大气路径是占主导地位的金属和Pb-210供应的沼泽，大气金属通量的区域格局和大气中的相对重要性，在邻近的长岛海峡贡献金属可以确定。湿地数据表明，Pb，Cu和Zn的大气通量在纽约市最大，并沿着长岛北岸向东减小。过剩的金属库存过剩Pb-210的沼泽和邻近的长岛海峡的潮下带沉积物中的比率的比较表明，大气供应可以贡献大部分的Ph（最多70-90%的综合输入）。Cu和Zn的大气贡献分别为
Deposition chronologies of six high saltmarsh cores collected in New York City and Long Island, New York, determined using excess Pb-210, show that accretion rates range from 0.1 to 0.4 cm year(-1). On average the marshes are accreting within about a factor of two of the rise in mean sea level for the area. Excess Pb-210 inventories in the marshes average 31 +/- 14 dpm cm(-2), comparable to values expected from atmospheric deposition of Pb-210. Chronologies of fluxes of Cs-137 and excess Pd, Cu, Zn and Cd (defined as values in excess of the pre-anthropogenic background at depth in a core) indicate significant migration of Cs-137 and Cd in the marsh cores. Lead shows maximum fluxes between 1970 and 1980, consistent with the historical record of consumption of leaded gasoline in the U.S.A. Copper shows recent decreases in flux at four of the six sites and Zn shows variable patterns. Fluxes of Pb, Cu and Zn are generally less than or equal to directly measured atmospheric fluxes of these metals, indicating the importance of atmospheric supply of the metals to the marsh sites. Assuming that the atmospheric pathway is dominant for both metal and Pb-210 Supply to the marshes, the regional pattern of atmospheric metal fluxes and the relative importance of the atmosphere in contributing metals to adjacent Long Island Sound can be determined. The marsh data indicate the atmospheric fluxes of Pb, Cu and Zn are greatest in New York City and decrease eastward along the north shore of Long Island. Comparison of the ratios of the inventories of excess metals to excess Pb-210 in the marshes and in the subtidal sediments of adjacent Long Island Sound suggests that atmospheric supply can contribute large fractions of Ph (at most 70-90% of integrated input). The atmospheric contributions of Cu and Zn are