Tungsten Distribution in Soil and Rice in the Vicinity of the World's Largest and Longest-Operating Tungsten Mine in China

Abstract

The objective of this study is to investigate tungsten (W) contamination in soil and its enrichment in rice in the area of the world's largest and longest-operating W mines in China. Root zone soil and rice plants were sampled at 15 sites in the agricultural field adjacent to W mines and analyzed for Al, Fe, Mn, Sc, and W contents and W chemical forms in the soil samples and W contents in the rice root, stem, leaf, and grain samples. Results showed that W content in the soil ranged from 3.99 to 43.7 mg kg−1, with more than 90% of W in the residual fraction, showing its low mobility and bioavailability. Average W contents in the rice root, stem, leaf, and grain were 7.06, 2.34, 4.76, 0.17 mg kg−1, respectively. In addition, they were linearly independent of W content and chemical forms in the soil. Average enrichment factor values were 0.39, 0.13, 0.28, and 0.01 for the root, stem, leaf, and grain, respectively. In can be concluded that W mining activity in the Dayu county contaminated the nearby agricultural soil and led to W bioaccumulation in the rice. This may pose a health risk to residents via food and soil ingestion, which should be a focus of scrutiny.

High-resolution measurement and mapping of tungstate in waters, soils and sediments using the low-disturbance DGT sampling technique

“…Comparison of the soil R values (0.06-0.09) from this study with those for other metals (Cd, Zn, Ni and As), encompassing a wide range of soil types [54][55][56][57], shows that typically W resupply is relatively poorly sustained. This is further supported by the high (>90%) non-available residual fraction of W observed in acidic and neutral soils [10,18,58]. Johannesson et al, [59] concluded that W adsorption with mineral surface sites intensifies with increased H + and Fe concentrations in oxic, suboxic and anoxic groundwater systems.…”

“…X-ray tubes) [5][6][7], industrial catalysts [8] and ammunition [9]. The country with the most acute W pollution problems is China [10]. In 2010, 85% of the 61,000 t of W that were produced worldwide that year came from within Chinese borders [10], with the mineral extraction activities concentrated in the south-eastern provinces of Jiangxi and Guangdong.…”

“…The country with the most acute W pollution problems is China [10]. In 2010, 85% of the 61,000 t of W that were produced worldwide that year came from within Chinese borders [10], with the mineral extraction activities concentrated in the south-eastern provinces of Jiangxi and Guangdong. The pollution legacy caused by W enrichment in some of these mining districts is severe [10,11].…”

“…In 2010, 85% of the 61,000 t of W that were produced worldwide that year came from within Chinese borders [10], with the mineral extraction activities concentrated in the south-eastern provinces of Jiangxi and Guangdong. The pollution legacy caused by W enrichment in some of these mining districts is severe [10,11]. However, it's not just the manufacturing processes that are a cause of concern, leachates from E-waste repositories and recycling sites can also contain considerable amounts of W [12].…”

“…The assumption that W is inert in soil/sediment and does not dissolve readily in water, perhaps accounts for why its biogeochemistry has not been so extensively studied compared to other toxic trace elements. However, recent research linking W to the development of a cluster of childhood leukemia cases in Neveda (USA) [13] coupled with a greater appreciation of the mobility of the element in soils/sediments and its uptake by biota, especially at pH's above 6.5 [5,10,16,17], have led the U.S. EPA to re-classify W as an "emerging contaminant" [18]. The distribution and fate of W in the soils/water is controlled by numerous factors including: pH, redox potential, existing chelating and precipitating agents, and Fe/Mn concentrations [19][20][21].…”