Heavy metal contamination of soil,and bioaccumulation in vegetables irrigated with treated waste water in the tropical city of Varanasi,India

The present study was conducted to determine the heavy metal contamination in soil with accumulation in plants in waste water irrigated areas. Results revealed that waste water contained lower concentrations of Cr, Zn, Cu, and Pb except Cd (0.03) than the permissible limits prescribed by the World Health Organization. The maximum metal concentrations occurred in Brassica oleracea (Zn 63.80, Cu 12.25, Cr 10.65, Pb 3.63, and Cd 0.56 mg Kg^?1).The metal enrichment (EF of Cd 1.9, Cr2.9, Zn 4.8, Cu 6.5, and Pb 15.5) and degree of contamination (CF of Cd 2.9, Cr 2.0, Zn 2.3, Cu 2.7, and Pb 2.2) showed that accumulation of the five toxic metals increased during sewage irrigation as compared with the reference values, other Indian regions and globally. However, based on WHO standards for heavy metal contamination of soil and irrigation water, our data does not ensure safe levels for food.     

Physiological and metabolic effect of mercury accumulation in higher plants system

Heavy metals, lead (Pb) and mercury (Hg) are non-essential elements. Plants absorb these metals from soil, water and air through their roots and leaves. Heavy metals are the major environmental pollutants, which spread to soil through the use of pesticides, herbicides and micronutrient fertilizers, industrial effluents, decay of junk materials and sewage sludge, vehicular emissions, re-suspended road dust, diesel generator sets and coal-based thermal power plants. Sewage and sludge have contributed to heavy metal contamination of peri-urban lands and vegetable crops. The present review focuses on the effects of various concentrations of Hg on growth of young and mature seedlings as well as on nitrate reductase activity and nitrate assimilation in intact and excised seedling, especially the mechanism underlying nitrate reductase regulation by this heavy metal. Evidence indicates that mercury exerts significant adverse effects on the physiological activity of plants.     

Impact of rhizobacteria on growth and chromium accumulation in Scirpus lacustris L. grown under chromium supplementation

Four chromate tolerant rhizobacterial strains viz., RZB-01, RZB-02, RZB-03 and RZB-04 were isolated from rhizosphere of Scirpus lacustris collected from Cr-contaminated area. These strains characterized at morphological and biochemical levels. The most efficient chromate tolerant strain RZB-03 was inoculated to fresh plant of S. lacustris and grown in 2 microg ml(-1) and 5 microg ml(-1) of Cr+6 supplemented nutrient solution under controlled laboratory condition. The effects of rhizobacterial inoculation on growth and chromium accumulation in S. lacustris were evaluated. The inoculation of rhizobacteria increased biomass by 59 and 104%, while total chlorophyll content by 1.76 and 15.3% and protein content increased by 23 and 138% under 2 microg ml(-1) and 5 microg ml(-1) concentrations of Cr+6, respectively after 14 d as compared to non-inoculated plant. Similarly, the Cr accumulation also increased by 97 and 75% in shoot and 114 and 68% in root of inoculated plants as compared to non inoculated plants at 2 microg ml(-1) and 5 microg ml(-1) Cr+6 concentrations, respectively after 14 d. The chromate tolerant rhizobacteria which play an important role in chromium uptake and growth promotion in plant may be useful in development of microbes assisted phytoremediation system for decontamination of chromium polluted sites.     

Temperature related seasonal changes in Golgi complex of brain, heart and intestine of a teleost

Impact of temperature related seasonal changes in density of Golgi complex were studied in brain, heart and intestine of the freshwater catfish, Clarias batrachus (Linnaeus). The density of Golgi complex was more in these organs of the fish acclimatized to a lower temperature (20 degrees C) than that to a higher temperature (29 degrees C). This suggests that lower temperature induces secretory activity in cells to cope up with the changes in surrounding environment. It could be a kind of histophysiological adaptation in poikilothermic animal.     

Induction of oxidative stress by benzo(a)pyrene in the epididymis of Wistar rats

The present study was undertaken to evaluate the effect of sub-chronic exposure to benzo(a)pyrene on the antioxidant system and histology of rat epididymal sperm. Intraperitoneal administration of benzo(a)pyrene to male Wistar rats at doses between 1 and 100 µg/kg body weight for 60 days entailed a decrease in the weight of the epididymis (caput and cauda), seminal vesicle, and prostate, while the body weight was not affected. Epididymal sperm reserves were reduced in a dose-dependent manner. Indicators of lipid peroxidation were increased while activities of superoxide dismutase and catalase in all three epididymal regions decreased. Histological malformations were observed in the epididymis. Exposure to benzo(a)pyrene deranges the antioxidant defense system and induces histological changes in the epididymis.     

Carbon capture,storage, and usage with microalgae: a review

Environmental Chemistry Letters - Global warming is induced partly by rising atmospheric carbon dioxide levels, calling for sustainable methods to sequester carbon. Here we review carbon capture,...     

Pyrene remediation by Trametes maxima: an insight into secretome response and degradation pathway

Environmental Science and Pollution Research - The rapid pace of economic development has resulted in the release of several polycyclic aromatic hydrocarbons (PAHs) into the environment. Microbial...     

Development of an environmental-friendly durable self-compacting concrete

Environmental Science and Pollution Research - In this experimental study on self-compacting concrete (SCC), the Manufactured sand (M-sand) and Fly ash (FA) were utilised for partial replacement of...