An assessment of trace element contamination in intertidal sediment cores of Sunderban mangrove wetland, India for evaluating sediment quality guidelines

This paper presents a comprehensive account regarding concentration, distribution and possible sources of trace elements (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in 20-30 cm sediment cores (<63 microm particle size) collected at the confluence of the Ganges River and Bay of Bengal (Sunderban wetland, India). This work aims to evaluate the fluvio-marine and geochemical processes influencing the metal distribution. The most interesting features are the downward increase of concentrations of majority of the elements reaching overall maximum values at a depth of 10-15 cm observed in station Lot No.8 located along the main stream of the Ganges estuary as well as an overall elevated concentration of all the elements in the lower littoral zone. The interelemental relationship revealed the identical behaviour of elements during its transport in the estuarine environment. The overall variation in concentration can be attributed to differential discharge of effluents originating from industrial and agricultural as well as from domestic sewage. Arsenic exceeded effects range - low (ER - L) concentrations, implying occasional or frequent adverse biological effects. For Cu, Ni and Cr a smaller proportion of samples had exceeded the ER - L values indicating that the dataset would be suitable for future use in evaluating predictive abilities of SQGs.     

Characterization of cadmium-resistant Klebsiella pneumoniae MCC 3091 promoted rice seedling growth by alleviating phytotoxicity of cadmium

Environmental Science and Pollution Research - Cadmium (Cd) phytotoxicity in agricultural land is a major global concern now-a-days resulting in very poor yield. Plant growth-promoting...     

Induction of oxidative stress by non-lethal dose of mercury in rat liver: possible relationships between apoptosis and necrosis

Sprague Dawley strain of male rats weighing 200 +/- 10.0 g, were exposed intramuscularly to non-lethal dose of mercury for short acute duration of 24 and 48 hr. Mercury treatment increased thio-barbituric acid reactive substance (TBARS) and conjugated diene (CD) content with increase in duration when compared with control. This reflects possible increase in lipid peroxidation, revealing that sufficient intoxication was generated by non-lethal dose of mercury. Furthermore, mercury treatment decreased tissue glutathione (GSH) content to 2.07 and 1.49 microg GSH mg protein(-1) with concomitant decrease in glutathione-S-transferase (GST) activity by 26.06 and 36.40% after 24 and 48 hr of exposure respectively. The elevations of aspartate transaminase (AST) and alanine transaminase (ALT) levels measured exhibited increase of 287.5 and 214.5% after 48 hr of exposure respectively which were found to be highly significant compared with control. Western blot analysis indicated upregulation of caspase-9 and upsurge in effect or caspase-3 activity leading to apoptosis. The concluded findings of the present investigation suggests possible role of early mercury exposure in inducing oxidative stress mediated apoptosis in mammalian model systems as an indicator component of environmental toxicology.