Comparison of arsenic and antimony biogeochemical behavior in water, soil and tailings from Xikuangshan, China.

Although similar geochemical behaviors of arsenic (As) and antimony (Sb) in the environment has been assumed and widely reported, growing evidence suggests the two elements cannot, under some conditions, be assumed to behave similarly. In this four-year study (samples collected in each year), comparative investigation of the biogeochemistry of As and Sb in water/fish, soil/vegetable, tailings/plant samples were carried out at the world's largest active Sb mine area (Xikuangshan, China). Depending on duration the tailings had been stacked, significant differences in spatial distributions between As and Sb were found, and these were associated with change in pH over time. Bio-accumulation factors (BAFs) of As were approximately 10-fold greater than those of Sb in fish/water, plant/tailing, and vegetable/soil systems. Sb had higher BAF in non-fatty tissues such as gills of fishes and shells of crabs. BAFs of Sb in vegetable/soil exhibited insignificantly, but different from As, positive correlation with pH in soil.

Arsenic, antimony, and bismuth uptake and accumulation by plants in an old antimony mine, China.

Arsenic (As), antimony (Sb), and bismuth (Bi) are metalloids that share similar chemical properties, the objective of this study was to characterize the uptake and accumulation of these metalloids by plants colonized on heavy contaminated sites in an old Sb mine. Sixty-five plant samples from seven species as well as the associated soil samples were collected at ten sites of Xikuangshan (XKS), Hunan province, China. Concentrations of As, Sb, and Bi in plants and soils were measured. As, Sb, and Bi were found to be evidently elevated due to the long history and intensive mining and smelting activities; the respective ranges for the levels of As, Sb, and Bi at the sites were 40.02-400.2 mg kg(-1) As, 610-54,221 mg kg(-1) Sb, and n.d. to 1,672 mg kg(-1) Bi. No correlation was found between As and Sb at the sites, while Bi was found to be positively correlated with As whereas negative with Sb at the sites. In general, the contents in the plants in XKS were in the order of As > Sb > Bi, and the contents of As was positively correlated with Sb and Bi in plants. The highest contents of As and Sb recorded was 607.8 mg kg(-1) As in Pteris vittata and 90.98 mg kg(-1) Sb in Hippochcaete ramosissima, while the highest Bi content as 2.877 mg kg(-1) Bi was measured in Buddleja davidii. Bioconcentration factors defined as the ratios of metalloids in shoots of plants to those in soils for various plants were lower than 1. The results showed plants colonized at the heavy contaminated sites in XKS had great tolerance to As, Sb, and Bi, and demonstrated similarities in plant uptake and accumulation of these three elements.

[Sediment record of DDTs in sediment core from Hongfeng reservoir].

In order to reconstruct the chronology of 2,2-his (4-Chlorophenyl)-1,1,1-trichloroethane (DDT) input into the Hongfeng reservoir and assess the pollution issues, the temporal distribution of DDT in sediment core from Hongfeng reservoir was measured using GC/MS method, and the possible sources and potential risk assessment also had been identified. The DDTs (sum of p,p'- and o,p'-DDT, DDE and DDD) in sediment core were ranged from 7.6 to 23.7 ng/g, and roughly, ever decreased from the bottom to the surface sediment. In detail, a sharp decline of DDTs concentration in sediment was found from 1981 to 1983, followed by a tardy decrease trend to the present. The DDTs in sediment were mainly composed of p,p'-DDTs (sum of p,p'-DDT, DDE and DDD). The ratio of p,p'-DDTs to o,p'-DDTs (sum of o,p'-DDT, DDE and DDD) ranged from 5.1 to 8.4, which suggests that the DDTs in sediment were chiefly originated from the technical DDT. Meanwhile, the DDTs in sediments were dominated by the metabolites of DDT (DDD and DDE) and the ratio of DDT/(DDD + DDE) were between 0.31 and 0.84, indicating the DDTs in sediment were mostly stemmed from the historical usage. Besides, the vertical profile of the ratios of DDT/( DDD + DDE) and DDE/DDD indicate that possible usage of technical DDT still occurred in the drainage area of Hongfeng reservoir around 1990, although the usage of technical DDT in agriculture has been banned in 1983. The residue levels of DDE, DDD, DDT, and DDTs in surface sediment from Hongfeng reservoir were all between ERL and ERM, suggesting potential risk could occur, and the contamination of DDT in Hongfeng reservoir deserving more concerns.

Antimony, arsenic and mercury in the aquatic environment and fish in a large antimony mining area in Hunan, China.

Antimony (Sb) has received increasing attention recently due to its toxicity and potential human carcinogenicity. In the present work, drinking water, fish and algae samples were collected from the Xikuangshan (XKS) Sb mine area in Hunan, China. Results show that serious Sb and moderate arsenic (As) contamination is present in the aquatic environment. The average Sb concentrations in water and fish were 53.6 + or - 46.7 microg L(-1) and 218 + or - 113 microg kg(-1) dry weight, respectively. The Sb concentration in drinking water exceeded both Chinese and WHO drinking water guidelines by 13 and 3 times, respectively. Antimony and As concentrations in water varied with seasons. Fish gills exhibited the highest Sb concentrations but the extent of accumulation varied with habitat. Antimony enrichment in fish was significantly lower than that of As and Hg.

[Pollution characteristics of antimony, arsenic and mercury in human hair at Xikuangshan antimony mining area and Guiyang City, China].

The concentration levels of antimony, arsenic and mercury in human hair collected from Xikuangshan antimony mining area and Guiyang City were determined by hydride generation-atomic fluorescence spectrometry after having been digested by nitric acid and perchloric acid. The contents of Sb, As and Hg are 15.9, 4.21, 1.79 microg/g in the samples from Xikuangshan antimony mining area and 0.532, 0.280, 0.338 microg/g in the samples from Guiyang City respectively. The contents of Sb, As and Hg in human hair of Xikuangshan antimony area are much higher than those of Guiyang City. The independent-samples t-test shows that there are no marked differences in the contents of Sb and As between male and female hair samples from both Xikuangshan antimony mining area and Guiyang City (p > 0.05), while Hg contents in male hair are apparently higher than those in female hair from Guiyang City (p < or = 0.05). There is positive correlation observed between As and Sb, as well as between As and Hg, while Sb is weakly correlated with Hg (p < or = 0.01). These results show that the heavy metals (Sb, As and Hg) in antimony mining area may significantly affect human health than in the un-mining areas.