Sources and the distribution of heavy metals in the particle size of soil polluted by gold mining upstream of Miyun Reservoir, Beijing: implications for assessing the potential risks

• Published in: Environmental monitoring and assessment 2014-10, Vol.186 (10), p.6605-6626
• Main Authors: Li, Qian, Ji, Hongbing, Qin, Fei, Tang, Lei, Guo, Xinyue, Feng, Jinguo
• Format: Article
• Language: English
• Subjects: anthropogenic activities; Anthropogenic factors; arsenic; Atmospheric Protection/Air Quality Control/Air Pollution; breathing; cadmium; chromium; clay; cobalt; Copper; correlation; Drinking water; Earth and Environmental Science; Ecology; Ecotoxicology; emissions; Environment; Environmental Management; Environmental Monitoring; Geochemistry; gold; Gold mines & mining; Health risks; Heavy metals; human health; Industrial Waste - analysis; Industrial Waste - statistics & numerical data; Inhalation; lead; Mercury; Mercury (metal); Metal concentrations; Metals; Metals, Heavy - analysis; Mining; Monitoring/Environmental Analysis; nickel; Organic matter; Particle Size; Particulate matter; polluted soils; Reservoirs; Risk; Risk Assessment; Samples; silt; Soil (material); Soil - chemistry; Soil Pollutants - analysis; Soil pollution; soil sampling; Soil surveys; Statistical analysis; Statistical methods; Trace metals; Upstream; zinc
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-014-3877-4

Mining has been carried out upstream of Miyun Reservoir, Beijing, for several decades, and has caused metal emissions to the environment, threatening human health. We conducted a soil survey to assess metal contamination in this area and to determine distribution of heavy metals in the particle size. We attempted to determine the possible sources of the metals and the significance of metals in the fine particle fractions to soil risk assessments. Thirty-four soil samples were collected, and eight samples were partitioned into seven size fractions. Most of the metal concentrations in the soils were higher than the background levels in Beijing, and the metal concentrations and total organic matter (TOC) contents generally increased as the particle size decreased. Each metal except Hg significantly positively correlated with the TOC. The metals in the coarse-grained soils were mainly derived from parent materials, but the metals in the fine fractions were mostly anthropogenic. Statistical analyses showed that there were three metal sources: Cd, Cu, Hg, Pb, and Zn had anthropogenic sources; Co, Cr, Ni, and V had mixed anthropogenic and natural sources; and As and Be had natural sources. The trace metals were primarily in the clay and fine silt fractions, and they might pose health risks through the inhalation of resuspended soil particles (PM10 and PM2.5). The elevated accumulation factors, enrichment factors, and ecological risk indices for the metals in the fine fractions suggest that risk assessments should be based on the fine particle size.