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91.
Efforts to reduce the energy needs to heat or cool dwellings have the potential to create new health hazards. Increases in indoor levels of radon and its progeny from the reduction in air exchange rates add a substantial radioactive burden to the general population. Other indoor pollutants reaching critical concentrations in homes with low air exchange rates are CO and NO2 from unvented combustion in gas stoves and heaters, tobacco smoke, and asbestos fibers. In addition, insulation materials and certain types of furniture may contribute the toxicant formaldehyde diffusing from foam injected walls or chipboard. Risk estimations using linear dose-response relationships show risk factors per kWh saved which are orders of magnitude greater than for a kWh produced by large power plants using coal, oil, gas, or uranium.  相似文献   
92.
In this paper, we develop an approach for identifying the location of populations most vulnerable to extreme heat events and how those locations change over time. We scan the literature on measuring vulnerability, especially sensitivity and adaptive capacity of populations. We employ Census data for metropolitan Chicago for the years 1990, 2000, and 2010, and maximum likelihood factor analysis to derive an index and map the distribution of Census tracts where residents exhibit greater sensitivity and/or lower adaptive capacity to extreme heat. Our findings show a pattern of deconcentration and decentralization of these populations within the city and region over time, with gentrification and the suburbanization of poverty trends observed in many US metropolitan regions as possible contributing factors. Finally, we discuss the implications of these findings for planning efforts in the study area and offer suggestions for further research.  相似文献   
93.
Some physico-chemical parameters of Kaljani River were studied in and around Alipurduar municipality. The principal characteristics of Kaljani River are high TSS, Mg-hardness, COD, and Phosphate 'P' Comparison of water quality parameters of the two rivers demonstrated higher range of alkalinity, ammonia 'N' content and chloride content in Torsa than Kaljani. River Kaljani showed higher COD range than Torsa. Mean BOD value of both these rivers ranged between 0.93-1.65 mg/l. Overall TDS content of Kaljani was found to be lower than Torsa. Maximum phosphate 'P' content was observed at the downstream of both the rivers.  相似文献   
94.
Adsorption study for the removal of a basic dye: experimental and modeling   总被引:1,自引:0,他引:1  
Chakraborty S  De S  DasGupta S  Basu JK 《Chemosphere》2005,58(8):1079-1086
An effective adsorbent is developed from saw dust and its various adsorption characteristics are studied for removing a basic dye (crystal violet) from its aqueous solution. Equilibrium data are fitted to various adsorption isotherms. It is seen that about 341 mg of crystal violet can be removed using 1g of the adsorbent at 298 K. Kinetic study is also carried out to observe the effects of various process parameters viz. particle size of the adsorbent, initial concentration of the dye, temperature and adsorbent amount. A generalized two-resistance mass transfer model, which includes a film mass transfer coefficient (k(f)) and an internal effective diffusivity (Dp), is used to interpret the adsorption kinetic data. The model parameters (k(f) and Dp) are estimated by fitting the experimental data to the model. The evaluated parameters are used to predict the concentration profiles at various other operating conditions. The average deviation of the predicted values lies within 10% in all the cases. Sensitivity analysis is performed to observe the sensitivity of the model to the variations in the model parameters.  相似文献   
95.
Thirty-six polyurethane foam disk passive air samplers (PUF-PAS) were deployed over a year during January to December, 2009 at three locations, i.e., Imphal (urban site), Thoubal (rural site) and Waithou (alpine site) of Manipur, to assess the seasonal local atmospheric emission of selected organochlorine pesticides (OCPs). The average concentration of HCHs monitored at mountain site during hot season (Mar, Apr, and May) and rainy seasons (Jun, Jul, Aug, and Sep) were 403 and 349 pg/m3, respectively. DDTs had a high concentration with 384 pg/m3 at rural site and 379 pg/m3 at urban site during hot seasons. Endosulfans and chlordane were found high in concentration during hot seasons (260 pg/m3) and low during retreating monsoon seasons (44 pg/m3) at rural site. Most of the OCPs concentrations were high during cultivation period. The OCP concentrations of rainy season were highly correlated (p < 0.01) with OCPs of hot seasons. Further, positive correlation (p < 0.05) was also obtained between cold seasons and retreating monsoon. Principal component analysis showed a significant correlation among the four seasons and distribution pattern of OCPs in air. Back trajectory analysis by using HYPSLIT model showed a long range air transport of OCPs to the present study area. Present OCP levels at Manipur is an outcome of both local emission and also movement of air mass by long range atmospheric transport.  相似文献   
96.
The paper describes differential tolerance of two fresh water crustaceans Mesocyclops hyalinus and Allodiaptomus satanus to 60Co gamma radiation. Mesocyclops hyalinus is dominant species at site 1, near a Thermal Power Plant at Kolaghat East Midnapore where fly ash deposition is a regular phenomenon. Allodiaptomus satanus is dominant species at site 2 at Kolkata, Ballygung where anthroponotic activities are more pronounced. M. hyalinus is naturally exposed to more stressful situation than A. satanus as revealed by comparing the hydrological parameters of the two habitats. Experimental exposure to ionizing radiation resulted in differential changes in viability morphology and antioxidant enzyme activities in the two selected species. Survival experiments showed greater tolerance of M. hyalinus compared to A. satanus up to 8Gy (absorbed dose) after which if showed drastic fail in survival. More pronounced morphological changes were observed in A. satanus as compared to that in M. hyalinus. The pattern of changes in antioxidant enzyme activity is distinctly opposite in the two radiation exposed species. While in M. hyalinus stimulation in activity of both CAT (excepting at 10Gy absorbed dose) and SOD was observed A. satanus showed decrease in activity of both the enzymes when compared to their unirradiated counterparts.  相似文献   
97.
Environmental Geochemistry and Health - Mangroves have wide applications in traditional medicines due to their several therapeutic properties. Potentially toxic elements (PTEs), in mangrove...  相似文献   
98.
Expression of the stress biomarkers 70-kDa heat shock proteins (Hsp70) and manganese superoxide dismutase (MnSOD) was measured as the molecular basis of adaptive response against increased experimental temperatures (32–40 °C for a span of 24–72 h) on the fresh water molluscan species, Bellamya bengalensis (Lamark 1882). The experimental snail specimens were collected during summer and winter seasons from two contrasting wetlands: an ecorestored (free from human interference) site (SI) and other experiencing anthropogenic stresses (SII). The mortality rate of the B. bengalensis and the immunoblotting of MnSOD and Hsp70 of their digestive glands were performed at regular intervals during the period of heat stress. The SI provided a lower stress environment based on physicochemical parameters such as pH, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), and alkalinity for the survival of test species, although both sites experienced mortality due to thermal stresses. The parity in protein expressions displayed a uniform mode of adaptive impact to temperature elevations in both field and laboratory exposure. The Hsp70 expression was minimal at lower thermal stress, but increased with a rise in temperature. It is very likely that higher Hsp70 levels are not directly related to survival or adaptation. In contrast, MnSOD levels appeared to be an indicator of adaptive responses vis-a-vis survival of the animals. So, the expression levels of a universal free radical scavenger like MnSOD are recognized as a potential biomarker in a bioindicator species like Bellamya.  相似文献   
99.
100.
Our study explores the nexus between forests and local communities through participatory assessments and household surveys in the central Himalayan region. Forest dependency was compared among villages surrounded by oak-dominated forests (n = 8) and pine-dominated forests (n = 9). Both quantitative and qualitative analyses indicate variations in the degree of dependency based on proximity to nearest forest type. Households near oak-dominated forests were more dependent on forests (83.8%) compared to households near pine-dominated forests (69.1%). Forest dependency is mainly subsistence-oriented for meeting basic household requirements. Livestock population, cultivated land per household, and non-usage of alternative fuels are the major explanatory drivers of forest dependency. Our findings can help decision and policy makers to establish nested governance mechanisms encouraging prioritized site-specific conservation options among forest-adjacent households. Additionally, income diversification with respect to alternate livelihood sources, institutional reforms, and infrastructure facilities can reduce forest dependency, thereby, allowing sustainable forest management.  相似文献   
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