Hylander L D, Meili M, Oliveira L J, de Castro e Silva E, Guimarães J R, Araujo D M, Neves R P, Stachiw R, Barros A J, Silva G D
Department of Limnology, Evolutionary Biology Centre, Uppsala University, Sweden.
Sci Total Environ. 2000 Oct 9;260(1-3):97-107. doi: 10.1016/s0048-9697(00)00544-1.
Sediments from nine floodplain lakes in Pantanal were analyzed for a large-scale (300 km) survey of mercury (Hg) load in sediments and soils of the Alto Pantanal and to study the relationship between Hg and reactive aluminum, iron, and manganese oxy-hydroxides. The results were compared with the Hg content in river and stream sediments from the Poconé gold mining area, where Hg has been extensively used and still is in use. The results indicate that the Hg concentrations were elevated in river sediment close to the mining area in Bento Gomes river basin (average in the < 74-microm fraction 88.9 ng Hg g(-1) dry wt.; interquartile range 50.3-119.5), but there was no clear indication that the local Hg emissions have contaminated the remote floodplain lakes, where concentrations were surprisingly low (average in the < 74-microm fraction 33.2 ng Hg g(-1) dry wt. sediment; interquartile range 18.4-46.8), in particular when considering geochemical characteristics of the sediment. The sediment from the floodplain lakes contained less Hg-tot and more reactive iron oxy-hydroxides than soils from the Tapajós area in the Amazon basin. This resulted in a mass ratio between Hg and amorphous oxy-hydroxides of only 5 x 10(-6) for Hg-tot/Fe-oxa (interquartile range 3-7 x 10(-6).
对潘塔纳尔湿地九个河漫滩湖泊的沉积物进行了分析，以对潘塔纳尔上游地区沉积物和土壤中的汞（Hg）负荷进行大规模（300公里）调查，并研究汞与活性铝、铁和锰的羟基氧化物之间的关系。将结果与波科内金矿区河流和溪流沉积物中的汞含量进行了比较，在该矿区汞曾被广泛使用且仍在使用。结果表明，本托戈麦斯河流域矿区附近河流沉积物中的汞浓度升高（<74微米部分的平均值为88.9纳克汞/克（干重）；四分位间距为50.3 - 119.5），但没有明确迹象表明当地汞排放污染了偏远的河漫滩湖泊，那里的浓度出奇地低（<74微米部分的平均值为33.2纳克汞/克（干重）沉积物；四分位间距为18.4 - 46.8），特别是考虑到沉积物的地球化学特征时。与亚马逊盆地塔帕若斯地区的土壤相比，河漫滩湖泊的沉积物中总汞含量较低，活性铁羟基氧化物含量较高。这导致总汞/无定形羟基氧化物的质量比仅为5×10⁻⁶（Hg-tot/Fe-oxa；四分位间距为3 - 7×10⁻⁶）。
