Smooth rock surfaces in arid environments are often covered with a thin coating of Fe–Mn oxyhydroxides known as desert varnish. It is debated whether such varnish is formed (a) by slow diagenesis of dust particles deposited on rock surfaces, (b) by leaching from the underlying rock substrate, or (c) by direct deposition of dissolved constituents in the atmosphere. Varnishes collected from smoot...

metal contents viz., cu, ni, co, zn and cd in sediment cores recovered from the vembanad lake, the largest estuarine-lagoonal system on the west coast of india, were analysed to understand the pollution levels and the impact on the coastal environment. of the three cores studied, vc-10 shown enrichment in all metals compared to other cores, as it is located in the vicinity of industrial area. f...

this study assesses the effect of major trace metals levels in wastewater discharges and sedimentfrom twenty four permanent and five semi-permanent wastewater drain outlets into the kuwait coast. theeffect of trace metals levels released from untreated wastewater discharges to euchelus asper, gastropod was also determined. results showed high trace metal levels in e. asper tissues, followed by ...

The effect of metal enrichment on chironomid communities was examined in streams receiving mine drainage from metal mining operations in New Brunswick, Canada. At five sites receiving mine drainage, metal concentrations were significantly (p < 0.05) elevated in water (Zn), periphyton (Cd, Co, Cu, and Zn), and chironomid tissue (Cu, Cd, and Zn) relative to five paired reference locations. Metal ...

the concentration of selected trace metals (fe, cd, cu, pb, and zn) in 30surface sediments were measured using atomic absorption spectrometer to investigatethe spatial and seasonal variations of trace metals along kanyakumari coast, india. toassess the environmental risk of trace metals, enrichment factor, geo-accumulation index,pollution load index, and ecological risk index have been calculat...

Seagrass beds are highly productive coastal ecosystems providing a large array of ecosystem services including fisheries and carbon sequestration. As seagrasses are known to be highly sensitive to anthropogenic forcing, we evaluated the use of trace metal concentrations in seagrasses as bioindicators for trace metal pollution of coastal regions at both global and local scale. We carried out a m...

Anthropogenic inventories for copper (229 ± 89 ug/cm2, N = 30), and mercury (470 ± 307 ng/cm2, N = 25) in Lake Superior sediments are much greater than inventories in remote lakes (Cu 50 ± 31 ug/cm2, Hg 64 ± 34 ng/cm2, N = 16) that receive inputs largely from long-distance atmospheric sources. Whereas the absolute concentration of mercury in Lake Superior sediments is not high (80–110 ng/g), en...

In this study we investigated the effects of competing trace metals and Ca2+ on Cd(II), Pb(II), and Cu(II) complexation by humic acid extracted from groundwater in Orange County, California. Two types of titration experiments were conducted, those using a single metal and those in which the humic acid had been preequilibrated with a competing metal (either a trace metal or Ca2+). The labile met...

Little research has been done on the land-sea exchange of trace elements, which is particularly applicable to ria coasts. In particular, trace metal enrichment in the inner part of the Ria of Vigo (the San Simon Inlet) has been observed from sediment studies but there is no information about Cd, Pb and Zn fluxes through the Rande Strait, which is the natural boundary of the estuary-ria water ex...