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Impact of metal cadmium on the nutritive value of Channa punctatus on exposure to a sublethal concentration (1.12 mg/l) of cadmium (Cd2+) for 15 and 60 days has been studied. Among the various parameters selected, the level of moisture in liver and muscle was increased, while decrease was noted in the level of ash, total proteins and inorganic constituents like iron, calcium, inorganic phosphate, sodium and potassium in both liver and muscle in the two types of exposure. The total lipid level of liver increased, while muscle lipid level was decreased. On the other hand, calcium, iron, inorganic phosphate, sodium and potassium levels showed increase in blood. Zinc and selenium decreased the percentage alterations in all the parameters selected for study. In the two types of exposure, zinc was most effective to counteract the cadmium toxicity to fish as in almost all the parameters insignificant alterations were recorded. In combination studies, protection against cadmium toxicity by the two chemicals became more marked with increase in the tenure of exposure.  相似文献   
2.
To observe the tolerance limit of lead phytotoxicity in cabbage (Brassica oleracea L.) var. Golden Aker plants were grown in refined sand with complete nutrient solution for 41 days. On 42nd day, pots with plants were separated into six lots. One lot was allowed to grow as such and was treated as control, in rest of the five lots, lead was applied at 0.1, 0.2, 0.4, 0.5 and 1.0 mM as lead nitrate. At d 75 (34 days after metal exposure), the lead toxicity symptoms as restricted growth was observed on plants at 1.0 mM lead supply. Excess lead (0.5 and 1.0 mM) developed interveinal chlorosis along the margins of young leaves. The affected leaves were reduced in size giving plant a rosette like appearance. Head size was markedly reduced at these (0.5 and 1.0 mM) levels of lead. At 0.5 mM the intensity of symptoms was markedly low. With an increase in lead supply, the concentration of lead and zinc was increased whereas that of P, S, Fe, Mn and Cu were decreased in various parts of cabbage. At 1.0 mM Pb, the concentration of lead was highest in roots and lowest in head. In leaves of cabbage the threshold of toxicity and toxicity values were 150 and 320 microg g-1 dry matter, respectively.  相似文献   
3.
Comparative toxicological studies of textile dye wastewater (untreated and treated) on a freshwater fish, Gambusia affinis, revealed a marked reduction in mortality and cytotoxic effects on RBCs, measured as reduction in their counts and percent changes in their shape (poikilocytosis) and variation in their size (anisocytosis)}, after subjecting them to both physicochemical and biological treatments. On comparing the data of mortality and the cytotoxic effects on RBCs, we found poikilocytosis is a better indicator for toxicity measurement of both untreated as well as treated wastewater, especially at their lowest concentrations where percent mortality was found to be either nil or lowerer than the percentage of poikilocytic RBCs. Although percent reduction in RBC counts and changes in their size (anisocytosis) indicated toxic effects of wastewaters, but EC5o values for RBC counts were usually higher than those for poikilocytosis and mortality, and non-calculable for anisocytosis suggesting their lesser sensitivity to pollutants. In view of these findings, we recommend monitoring of toxic effects of wastewaters during fish bioassay on both mortality and variation in RBC shape.  相似文献   
4.
The geochemistry of the suspended particulate matter (SPM) collected during the monsoon was determined to identify the sources of SPM and to understand the physicochemical processes in the Mandovi and Zuari river estuaries. The concentrations of SPM decrease seaward in both estuaries, but are relatively high at bay stations. Kaolinite is the most dominant clay mineral in the upstream of both rivers. Smectite increases seaward in both estuaries and is abundant in the bay. Upstream stations of Mandovi, where ore deposits are stored on the shore, exhibit high Fe, Mn, total rare earth elements (∑REE), and middle REE- and heavy REE-enriched patterns. Channel stations of both estuaries exhibit middle REE- and light REE-enriched patterns, which gradually changed seaward to middle REE- and heavy REE-enriched patterns. Canal stations exhibit the highest concentrations of major and trace metals. High metal/Al ratios occur at stations in the upstream of Zuari and at the confluence of canals in the Mandovi estuary. Enrichment factors of metals indicate that Mn is significantly polluted while other metals are moderately polluted. The δ 13C and δ 15N of organic matter indicate that the terrigenous organic matter at the upstream is diluted seaward by marine organic matter. Organic matter at bay stations is largely marine and altered-type. The compositions of SPM are controlled by the particulates from ore dust, the geology of the drainage basins, and the physicochemical processes in the estuaries. Particulates resuspended from the bay are dominated by ore dust, which are advected into the channels of both estuaries during the lull periods of the monsoon.  相似文献   
5.
Impact of domestic sewage on fresh water body   总被引:1,自引:0,他引:1  
In the present study various (physico-chemical) factors were assessed over a period of two years (from February 2002 to January 2004) to note the chemistry and quality of tank water in Bhalki town of Bidar. Physico-chemical factors like pH, dissolved oxygen, magnesium, chlorine, nitrite, sulphates and chemical oxygen demand were found with maximum concentration during summer season. Similarly, during monsoon season free carbon dioxide, alkalinity hardness, calcium, phosphate, silicon, total solids and biological oxygen demand; and in winter season organic matter were recorded. The concentrations viz., pH, hardness and nitrite were more compared to the potable water standard of WHO. The correlation matrix and dendrogram of physico-chemical factors have been computed and analysed. The positive co-relation coefficient observed between pH and magnesium, dissolved oxygen and hardness, free carbondioxide and calcium, alkalinity and nitrite, alkalinityand phosphate, alkalinity and biological oxygen demand, hardness and calcium, hardness and magnesium, magnesium and chlorine, nitrate and phosphate, nitrite and biological oxygen demand, phosphate and organic matter; and silicon and chemical oxygen demand. The dendrogram confirms chlorine, pH, hardness, silicon, total solids and sulphates are the key factors of the change in the chemistry of water body  相似文献   
6.
A new spectrophotometric method for the determination of benzene in air is described. The method is based upon the nitration of benzene to m-dinitrobenzene and subsequent reduction to m-phenylenediamine. m-Phenylenediamine is determined by diazotization-coupling reaction. α-Naphthol is used as a coupling reagent. Beer's law is obeyed in the range of 10–80 μg of m-dinitribenzene per 25 mL sample. The dye shows a wavelength of maximum absorption at 530 nm. The dye is stable for ~ 30 h. Toluene, the major interferent, can be separated. Beer's law, sensitivity, reproducibility, and other reaction conditions such as time, temperature, and acidity were studied. Formation of stable dye is the main advantage of the method over the butanone method for benzene, in which the colored complex is stable for only 5 min. It is possible to determine traces of benzene (0.05–0.30 μg/mL) by extracting the azo dye in 10 mL iso-amyl alcohol; this also increases the stability of the dye up to 42 h.  相似文献   
7.
Environmental Science and Pollution Research - Study was conducted utilizing a confirmed medication adherence scale to measure the socio-demographic profile, self-care, and medication...  相似文献   
8.
Bacteriological water quality status in terms of total coliform and faecal coliform count was studied on both--east and west banks of river Yamuna in Delhi. Membrane filtration technique was adopted for enumeration of total coliform and faecal coliform count in the river water sample collected on monthly basis for 2 years--2002 and 2003. The study reveals the impact of diverse anthropogenic activities as well as the monsoon effect on the bacterial population of river Yamuna in Delhi stretch. Microbial population contributed mainly through human activities prevailed in the entire stretch of Yamuna river with reduction in bacterial counts during monsoon period due to flushing effect. Bacteriological assessment does not provide an integrated effect of pollution but only indicate the water quality at the time of sampling. Hence, this parameter is time and space specific.  相似文献   
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