Determining environmental risk and source of heavy metal(loid)s in the surrounding farmland soil of a zinc smelter in water source area, Northwest China

Risk and source of heavy metal(loid)s (As, Cu, Cr, Pb, Mn, Ni, V, and Zn) were determined in the surrounding farmland soil of a zinc smelter in the water source area of the Mid–route of South–North Water Transfer Project of China to explore the impact of smelting activity on local environment. The heavy metal(loid)s contents were analyzed by X–ray fluorescence spectrometry and their pollution levels and ecological risks were assessed by geoaccumulation index, Nemerow synthetic pollution index and potential ecological risk index. The possible sources of the heavy metals(loid)s were identified by multivariate statistical analysis methods. The mean contents of the heavy metal(loid)s in the farmland soil were above the local soil background values except Mn. The contents of As, Cu, Pb, Zn, and Ni in the downwind direction soil decreased with the distance increasing between the sampling site and the zinc smelter. The investigated soils were moderately to seriously polluted by heavy metal(loid)s and the heavy metal(loid)s presented moderately ecological risk as a whole. As, Cu, Pb, and Zn mainly originated from zinc smelting activities. Cr, Mn, and V primarily derived from natural source. Ni mainly came from zinc smelting activities, partly from natural source. The zinc–smelting activity influenced the heavy metal(loid)s content, particularly Zn and Pb, in the surrounding farmland soil. The local government should strengthen the cooperative monitoring of heavy metal(loid)s in farmland and agricultural products, as well as pollutant emission monitoring and control.

Anthracological Analysis of Samples from Four Sites with Smelting Activity Around Virje and Hlebine

This contribution summarises the results of anthracological analyses conducted on the remains of charcoal from workshop and residential areas extracted during small-scale excavations at four sites around Virje and Hlebine. The aim was to determine wood taxa from iron production workshop contexts and from adjacent residential areas, or from other activities, such as timber construction or production of everyday objects. Further interests included reconstructing the availability of wood as a raw material and understanding the natural environment around the mentioned sites across various periods of their occupation and activities.

Ecological impact of fast industrialization inferred from a sediment core in Seocheon, West Coast of Korean Peninsula

Background Rapid industrialization has caused various impacts on nature, including heavy metal pollution. However, the impacts of industrialization vary depending on the types of industrializing activity and surrounding environment. South Korea is a proper region because the rapid socio-economical changes have been occurred since the late nineteenth century. Therefore, in this study, we estimate the anthropogenic impacts on an ecosystem from a sediment core of Yonghwasil-mot, an irrigation reservoir on the western coast of Korea, in terms of heavy metal concentrations, nutrient influx, and pollen composition. Results The sediment accumulation rate (SAR) determined by 210Pb geochronology showed two abrupt peaks in the 1930s and 1950s, presumably because of smelting activity and the Korean War, respectively. The following gradual increase in SAR may reflect the urbanization of recent decades. The average concentrations of arsenic (As), copper (Cu), and lead (Pb) during the twentieth century were > 48% compared to those before the nineteenth century, supporting the influence of smelting activity. However, at the beginning of the twenty-first century, the As, Cu, and Pb concentrations decreased by 19% compared to levels in the twentieth century, which is coincident with the closure of the smelter in 1989 and government policy banning leaded gasoline since 1993. The pollen assemblage and nutrient input records exhibit changes in vegetation cover and water level of the reservoir corresponding to anthropogenic deforestation and reforestation, as well as to land-use alteration. Conclusions Our results show that the rapid socio-economic development since the twentieth century clearly affected the vegetation cover, land use, and metal pollutions.

Classification et chronologie de bas fourneaux de réduction du fer à usage unique au sud-ouest du Niger

In southwestern Niger, near Niamey, several thousand singleuse bloomery furnaces have been mapped and identified. The archaeological study of approximately 30 furnaces and their slag reveals the existence of four methods for iron smelting: three types of pit furnace and one slag-tapping type. The slag pit furnaces are clearly differentiated by the form and volume of their pits. All slag-tapping furnaces drain off slag through small openings. The slag is tapped either vertically or laterally. According to radiocarbon dates, the smelting activity developed in the 2nd century AD and intensified through to the 14th century. It continued to evolve until the middle of the 20th century. The low intensity of iron production for these furnaces indicates the products were intended mainly for the local market.

Lake Acidification Recovery can be Monitored using Chrysophycean Microfossils

Chrysophyte scales in a sediment core from Swan Lake, Sudbury, Ontario were studied to examine their sensitivity for inference of recent lakewater pH change. The study indicates that, corresponding to an increase in metal mining and smelting activity in the Sudbury basin, lake acidification commenced in 1940. However, as a result of reductions in SO2 emissions in the early 1970's, the lake's pH has recovered from its chronic low pH of 4.0 in 1977 to its high of 5.6 in 1987. The chrysophyte-inferred pH recovery mirrors the increase in measured lakewater pH. The study identifies the potential of chrysophytes to document recent pH recovery in soft-water lakes containing undisturbed sediments. The approach offers promise for understanding the response in lakes of poorly buffered regions to decreased atmospheric loadings of SO2 and in establishing and implementing SO2 mitigation standards.