This paper examines the geochemical features of 8 soil profiles developed on metalliferous black shales distributed in the
central parts of the South China black shale horizon. The concentrations of 21 trace elements and 8 major elements were determined
using ICP-MS and XRF, respectively, and weathering intensity (W) was calculated according to a new technique recently proposed in the literature. The data showed that the black shale soils
inherited a heterogeneous geochemical character from their parent materials. A partial least square regression model and EFbedrock (enrichment factor normalized to underlying bedrock) indicated that W was not a major control in the redistribution of trace metals. Barium, Sn, Cu, V, and U tended to be leached in the upper
soil horizons and trapped by Al and Fe oxides, whereas Sb, Cd, and Mo with negative EF values across the whole profiles may
have been leached out during the first stage of pedogenesis (mainly weathering of black shale). Compared with the Chinese
average soils, the soils were strongly enriched in the potentially toxic metals Mo, Cd, Sb, Sn, U, V, Cu, and Ba, among which
the 5 first listed were enriched to the highest degrees. Elevated concentrations of these toxic metals can have a long-term
negative effect on human health, in particular, the soils in mining areas dominated by strongly acidic conditions. As a whole,
the black shale soils have much in common with acid sulfate soils. Therefore, black shale soils together with acid sulfate
soils deserve more attention in the context of metal exposure and human health. 相似文献
Intense mining, smelting, and tailing activities of polymetallic ore deposits have affected the environment in Nandan County, Guangxi, China. Samples of particulates with aerodynamic diameters low or equal 10 μm (PM10) were collected in Nandan County to investigate the concentrations of and health risks posed by 17 metals and metalloids in the PM10. The metal and metalloid concentrations were lower than those found in other industrial cities. The mean Cr concentration was 7.48 ng/m3. Significant higher metal and metalloid concentrations were found in PM10 from mining areas (Dachang and Chehe) than from the control area (Liuzhai) (p < 0.05). Principal component analysis indicated that the main sources of Ba, Co, Cr, Fe, K, Mg, Mo, Na, and Sr were resuspension of the soil produced through mineral erosion, the main sources of As, Cd, Cu, Pb, Sb, and Zn were smelting and mining activities, and the main source of Ni was fossil fuel combustion. Higher non-carcinogenic and carcinogenic risks were posed in Dachang and Chehe than in Liuzhai. The non-carcinogenic risks posed to adults and children by individual metals and metalloids in PM10 at all the sites were low, but the non-carcinogenic risks posed to children by all the metals and metalloids together exceeded the safe level (i.e., risk value > 1). The carcinogenic risks posed by Cd, Ni, and Pb were negligible at all sites, while As, Co, and Cr posed potential carcinogenic risks to the residents.
During chick-rearing, albatrosses can alternate between long foraging trips that provide the main source of food for the adults
and short foraging trips that they use to feed their young. This flexibility in foraging behaviour can lead to differences
in diet composition between adults and chicks and implies that they may be vulnerable in different ways to food shortages.
The trophic ecology of the Grey-headed albatross Thalassarche chrysostoma was investigated at the sub-Antarctic Prince Edward Islands during the chick-rearing period in April 2006 using a combination
of approaches. Diets of adults and chicks were assessed using stable isotope ratios and fatty acid (FA) profiles of blood
and/or stomach oils, in addition to stomach contents analysis. Fish from the family Macrouridae and cephalopods (particularly
the onychoteuthid Kondakovia longimana) were the primary prey, whereas crustaceans (krill Euphausia superba) represented a smaller proportion of the stomach contents. Stomach oil FA profiles contained more monounsaturated FA than
the profiles of plasma, which were richer in saturated FA and arachidonic acid (20:4n-6). There was also a distinct separation
of adults from chicks, with higher levels of monounsaturates in chick plasma, and higher saturated FA levels (particularly
16:0) in the adult plasma. Stable carbon isotope ratios of whole blood were similar in adults and chicks, whereas stable nitrogen
isotope ratios showed significant enrichment by >1‰ in chicks. The combined FA, stable isotopes and stomach contents analyses
suggest clear differences in diet quality between adults and chicks, with chicks feeding at a higher trophic position through
feeding more on highly nutritious fish and adults keeping much of the less nutritious zooplankton for themselves. 相似文献