Trace metals in fish,sediment and water from the south west coast of the Arabian sea,Pakistan

Concentrations of ten metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Hg) in the edible muscle of Arius maculatus captured from eight different near‐shore and off‐shore sites off the south west coast of the Arabian Sea, Pakistan, were determined by atomic absorption spectrophotometry. Relevant water and sediment samples from the sites were also analysed for the metals. Zinc showed the highest metal concentration (6.763 μg/g, wet weight) in the muscle of the fish, while Mn and Hg showed lowest level (0.019 μg/g, wet weight). Of all the metals investigated, largest scatter (measured as σ) was observed for Zn (σ = 2.058 /μg/g) in fish muscle, for Fe and Mn in sediment (σ = 27481 and 44.50 μg/g) and for As in water (σ = 0.270 μg/L). The metal distribution data pertaining to water, fish and sediment were examined on the basis of simple metal correlations. The statistical study revealed that Ni, Cr, Pb and Cu had significant positive correlations (r > 0.830 at ρ = 0.01). The finding substantiated a trace metal concentration gradient in the area, thereby indicating that the local marine environment is contaminated by anthropogenic sources.     

Scalp hair metal analysis in the assessment of the occupational exposure of arc welders

Eleven metals (Ca, Mg, Fe, Zn, Cu, Mn, Cd, Co, Cr, Ni and Pb) were estimated in hair samples of metal arc welders and a control group with the same socioeconomic background. Nitric acid–perchloric acid wet digestion procedure was adopted for the estimation of endogenous metal contents by ICP-AE technique. The study exhibited the following increasing order of the metal concentrations: Cd??1, dry weight, respectively. On average, the levels of Mn, Ni, Pb and Fe were found to be 1.5–2.4 times higher in the hair of welders compared with controls. Besides age and exposure which were strongly correlated, Cu–Mg, Mn–Mg, Ca–Co and Cd–Zn also showed significantly positive correlations. The identification of metal sources, done by cluster and principal component analyses, revealed four factors: age and exposure; Cu, Mg, Mn and Fe; Ca and Co; Cd, Zn, Ni and Pb. High levels of Fe were found to have a depleting impact on Co levels. The arc welders were feared to accumulate heavy metals in their bodies due to long-term endogenous exposure.     

Concentrations of Heavy Metals in Hair and Nails of Young Pakistanis: Correlation with Dietary Elements

Hair and nail samples from young Pakistani adults were separately analyzed for quantification of Cd, Cr, Cu, Ni, Pb, and Zn concentrations. The concentrations of these metals were also analyzed in commonly consumed local foods to evaluate potential correlation of hair and nail concentrations with diet. Pearson correlation coefficients ranged from 0.349 to 0.999, demonstrating diet to be a significant contributor for accumulation of heavy metals in humans.     

Antimony (Sb) – pollution and removal techniques – critical assessment of technologies

In view of increasing emissions of antimony (Sb) into the environment due to industrialization and consequent carcinogenicity, it is essential to remove this metal from the ecosystem. Antimony and arsenic (As) are analogs. Although numerous studies examined arsenic removal, few reports are available on Sb removal. In this review, various Sb removal techniques are described to understand how this process occurs and what research gaps are needed to improve efficiency. At present, surface adsorption technique is the most widely used for Sb removal. Biological treatment namely phytoremediation is also a promising method and more investigations are required in this regard. The selection of a suitable technique for a given area depends on the conditions including economic, environmental, and social conditions.     

Mechanisms of copper toxicity in the shore crab,Carcinus maenas

The influence of copper(II)chloride on selected key enzymes and metabolites in intermediary metabolism and the energy charge potential of the hyperregulating shore crab, Carcinus maenas (L.) were investigated. Crabs, collected in Odense Fjord, Denmark between September 1989 and May 1990, were exposed to 10 ppm copper(II)chloride, in 10 ppt salinity seawater at 15°C for up to 1 wk. Hexokinase activity was 77% lower in the posterior gills and 60% lower in the midgut gland than in control crabs. Phosphofructokinase activity was reduced in the midgut gland by 82% but was unaffected in the gills. Pyruvate kinase activity was undetectable in the gills of exposed crabs and reduced by 47% in the midgut gland. Citrate synthase activity was depressed by 30% in the posterior gills and unaffected in other tissues. Copper exposure had no apparent effect on tissue cytochrome c oxidase activity. Chela muscle was the only tissue in which copper exposure did not bring about reductions in the enzyme activities tested. As a result of 1 wk of copper exposure the average lactate level increased by 3.5-fold in haemolymph, 9.3-fold in posterior gills and 6.5-fold in midgut gland. The average glucose level was raised by a factor of 6 in the haemolymph, 3.4 in the posterior gills and 1.2 in the midgut gland. Energy charge potential was at a very high level (ca. 0.9) and was unaffected by copper exposure.     

Quantitative sustainability assessment of remanufacturing waste reinforcing steel

Construction is a major contributor to the solid waste stream globally and various recycling strategies are being evaluated to recover valuable resources. As a novel strategy, remanufacturing waste reinforcing steel bar (rebar) pieces from concrete waste to produce nails was applied on an industrial scale to prove the technical feasibility, where a group of alternatives were developed based on commercially available industrial machinery. The calculated economic and environmental feasibility values are sufficiently high for industrial application, and the most appropriate remanufacturing technological alternative was identified. The sustainability equation was solved to find the social feasibility and overall remanufacturing sustainability index. Rebar waste remanufacturing has a high triple-bottom-line sustainability index of 0.885. Based on the proposed process, small remanufacturing companies can be developed, thereby aiding employment and human development by earning profit of 1904–8880 USD/day. The findings of this study are beneficial to decision makers in government and industry and are globally relevant because concrete waste is ubiquitous worldwide.     

Evaluation of the Swat River,Northern Pakistan,water quality using multivariate statistical techniques and water quality index (WQI) model

Environmental Science and Pollution Research - This study evaluates the characteristics of water along the Swat River, Northern Pakistan. For this purpose, water samples (n = 30) were...     

The role of infrastructure,socio-economic development,and food security to mitigate the loss of natural disasters

Environmental Science and Pollution Research - This study shows the impact of risk (hazard, exposure, and vulnerability) and resilience (infrastructure, information and communication technology,...     

Environmental benefit of clean energy consumption: can BRICS economies achieve environmental sustainability through human capital?

Environmental Science and Pollution Research - This paper scrutinizes the asymmetric impact of education and education expenditure on clean energy consumption and CO2 emissions in the BRICS...