Anthropogenic Arsenic Sources in the Tampere Region

Abstract

This paper is the final report of TASK 2 which is part of the RAMAS project, in which scientists from the Helsinki University of Technology (TKK), Pirkanmaa Regional Environment Centre (PREC) and the Geological Survey of Finland (GTK) participated. The work was performed during 2005/2006. In this report, information about anthropogenic sources of arsenic in the Pirkanmaa region (also called the Tampere region) was gathered and RAMAS performed complementary sampling and analyses in potentially contaminated areas. Data was acquired about chemicals containing arsenic (wood preservative agents, pesticides etc.), the metal industry and metallic products containing arsenic (e.g. gunshots), mining and waste management. Available data was gathered from the Chemical Register (KETU), the Register of Contaminated Land Areas and the Register of Surface Waters maintained by the Finnish Environment Institute (SYKE) and the Regional Environment Centers of Finland, from environmental authorities and other very diverse sources. Dozens of unpublished file reports on the risk assessments and remediation of contaminated soils provided by consulting companies and previous studies made by the Regional Environment Centers of Finland were studied to gather information about arsenic contamination. Information about environmental impacts of mining industry was obtained from geological publications. The data acquisition was difficult because information about contamination, concentrations and risk assessments of arsenic is scattered in unpublished reports and informal papers. RAMAS studied areas affected by soil and surface water contamination in one wood preservative plant (52 field analyses and 5 samples analyzed in laboratory), two mines (6 tailings samples analyzed for geochemical composition, leachability and toxicity, 6 lake and stream sediment samples and over 60 surface water samples), waste treatment and municipal waste water treatment plants. In total, over 100 samples were analyzed. The acquired data as well as sampling and analyses performed by RAMAS confirmed that wood preservation plants are the major source for arsenic in the Pirkanmaa region. They may pose a risk to nearby residents, surface waters and groundwater, but only affect rather small areas. Shotgun shooting ranges are possible arsenic contaminated areas though lead is the main concern in these sites. The mining industry may affect vast areas through air and especially through surface waters, which was shown in the RAMAS studies in the former Ylöjärvi mine. Arsenic is transported from the mine area along a seven kilometers long watercourse to Lake Näsijärvi. The mining activities can be traced from the lake and stream sediments as high concentrations of arsenic and other heavy metals. The studies of waste management also show that, in general, waste material does not contain high concentrations of arsenic. However, point source pollution from wood preservative product wastes or disposed CCA-treated wood can be a contamination risk in the surroundings of older, poorly isolated landfills. In addition to old landfills, the area around of scrap yards, closed factories, old refineries, foundries and tanneries are potentially arsenic contaminated areas. Animal shelters, like fur ranges, and the plastic industry among many other human activities are also probable contaminants though arsenic is not the main detrimental element. However, all of the contaminated sites in the Pirkanmaa region are relatively small compared to other European countries, such as extensive mining areas in southern Spain.