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61.
The composition and variability of airborne fungal spores were studied using two complementary sampling methods in an outdoor environment in Kolkata suburb for 2 years, from November 2002 to October 2004. For monitoring the total fungal spore burden in the air, Burkard 7-day volumetric sampler was used, whereas Andersen two-sage viable sampler was used for isolating the cultivable airborne fungi. Among the 37 fungal spore types identified in the air samples, the predominant ones were Cladosporium, unidentified ascospores, unidentified basidiospores, Aspergilli/Penicilli, Nigrospora, Periconia, Chaetomium, Drechslera, Alternaria, Coprinus, Ganoderma, Pithomyces, and rust spores. Only six fungal spore types (Alternaria, Aspergilli/Penicilli, Cladosporium, Curvularia, Drechslera, and Nigrospora) were recovered in common by the two samplers. For Aspergilli/Penicilli, Drechslera, and Nigrospora, the spore concentration was underestimated in the non-viable sampling method (Burkard sampler). In general, higher spore count was recorded in winter. The highest fungal species variability was observed in early monsoon (June). Relative humidity could significantly predict the seasonal periodicity of the maximum number of airborne spores. The total airborne fungi concentration recorded in the study (15-16?×?10(3) spores m(-3) of air) was lower than the proposed threshold limit value for clinical significance, suggesting apparently no or less airborne-fungi-exposure-related health risk in the sampling area. Cladosporium cladosporioides was recorded beyond the proposed threshold limit value in January 2003 and March 2004; Aspergillus fumigatus and Aspergillus nidulans in winter that might have posed considerable health risk to sensitized individuals.  相似文献   
62.

Background

In this paper, batch removal of hexavalent chromium from aqueous solutions by Araucaria heterophylla leaves was investigated. The batch experiments were conducted to study the adsorption of metal species and effect of different pH, contact time, metal concentration, biosorbent concentration, and adsorption capacity.

Method

Freundlich and Langmuir??s isotherm model were used to describe the adsorption behavior, and the experimental results fitted Freundlich model well.

Results

The adsorption efficiency observed for all chromium concentrations, i.e., 1, 3, 5, and 10?mg/L was 100% and the equilibrium was achieved in 30?min for 1 and 3?mg/L, whereas for 5 and 10?mg/L, it was less than 60?min. FTIR spectra was taken to identify functional groups involved in the biosorption.

Conclusion

Thus, Araucaria leaves can be considered as one of the cheap and efficient biosorbent for toxic hexavalent chromium removal from natural or wastewaters.  相似文献   
63.
This paper shows that gas/particulate phase partitioning of polycyclic aromatic hydrocarbons (PAHs) can be monitored using lichens. Anthropogenic sources are responsible for the release of PAHs, which are bioaccumulated in plants at various spatial scales based on their physicochemical properties. Atmospheric PAHs are distributed both in the gaseous and particulate states. Here, a lichen species, Dermatocarpon vellereum Zschacke, has been collected at different altitudes in and around the Rudraprayag valley, located in Central Himalayan region of India, in order to study the spatial distribution of PAHs in the valley. Results show that PAH concentration ranged from 0.136 to 4.96 μg g?1. Findings reveal that the bioaccumulation of 2- and 3-ringed PAHs was higher in high-altitude samples, whereas bioaccumulation of fluoranthene, a 4-ringed PAH, showed higher concentration in samples from localities away from town centre. 5- and 6-ring PAHs were then confined to the lower altitude at the base of the valley, thus justifying their particulate-bound nature. This is the first report showing the utility of lichen to biomonitor PAHs in the Himalayan ecosystem.  相似文献   
64.
Lichens to distinguish urban from industrial PAHs   总被引:1,自引:0,他引:1  
This paper shows that lichens can be used as biomonitors to distinguish urban from industrial polycyclic aromatic hydrocarbons (PAHs). PAHs are atmospheric pollutants originating mainly from incomplete combustion of fuels in vehicles and industry. The occurrence of PAHs in air is a serious health issue in urban areas and industrial areas because some PAHs are carcinogenic. Biomonitoring PAHs with lichens is generally applied for quantification of PAHs. However, the precise sources of PAHs are not well known. Here we use lichen to trace the source of PAHs. PAHs were analyzed in Pyxine subcinerea Stirton, a lichen species collected from twelve sites which vary from urban and industrial to periurban forest area of Haridwar, in the foothills of the Indian Himalayas. Total PAH concentration ranged between 1.25 and 187.3 μg g−1. Results indicate a clear distinction between urban and industrial PAHs profile, using principal component analysis. Lichen sampled from industrial sites exhibited higher concentrations of two-, five-, and six-ringed PAHs, up to 60% of total PAHs, while samples from urban sites were dominated by four-ringed PAHs, predominantly fluoranthene and acenaphthylene. Molecular ratios indicate that combustion was the dominant source of origin of PAHs in industrial area, while urban sites showed mixed origin of PAHs, both pyro- and petrogenic.  相似文献   
65.
Effect of cement dust on the growth and yield of Brassica campestris L   总被引:1,自引:0,他引:1  
Plants of Brassica campestris L. var. G-S20 were treated with cement dust, at rates of 3 (B(1)), 5 (B(2)) and 7 (B(3)) gm(-2) day(-1) for 90 days. Treated plants showed a consistent reduction in growth, photosynthetic pigments, yield and oil content over control plants. The overall phytomass of treated plants was significantly decreased, the maximum reduction being 64.8% in B(3) plants, followed by B(2) plants (55.3%) and B(1) plants (43.69%) at 60 days. The effect on oil content was also greatest in B(3) plants, where it was decreased by 6.13%.  相似文献   
66.
ABSTRACT

Radiant floor systems have the potential to reduce energy consumption and the carbon footprint of buildings. This study analyzed a novel radiant panel configuration comprising a metal plate with small spikes that can be pressed into cement board or wood. The behavior of this configuration was simulated for different materials for the metal plate, spike dimensions, and varying spacing between spikes. An annual energy simulation model compared the radiant panel configuration with the traditional concrete-based system. Simulations were run under heating dominant, cooling dominant, and neutral conditions; significant cost savings and greenhouse gas emission reduction were seen across all scenarios.  相似文献   
67.
Grass pollens are well known among the health hazardous bioaerosols causing respiratory allergy. Being an important member of the grass family, the rice plants contribute a huge pollen load in agricultural fields during flowering. This results in a seasonal trigger of hay fever and respiratory allergy in the field workers and people living in the vicinity. Studies on the monitoring of airborne rice pollen and the intensity of the released allergen in agricultural fields are largely lacking. The aims of the present study were: (1) daily and hourly monitoring of airborne rice pollen in an agricultural field during the flowering period of plants in a winter crop season by using the Burkard 7-Day Volumetric Sampler and (2) the measurement of hourly airborne allergen intensity in the field in a peak rice pollen period by the double-antibody and chemiluminescence techniques to find out its relationship with the airborne rice pollen concentration. The monthly average concentration of rice pollen was 95 pollen m(-3) and the range of daily average pollen concentration was 0 to 386 pollen m(-3). A bimodal diurnal periodicity showed that the airborne rice pollen concentrations remained high at two different times of the day: between 08:00 h to 12:00 h and 14:00 h to 16:00 h. Deposition of airborne rice pollen allergen showed darker intensities on the immunostained tapes from the Burkard Sampler at the same two positions corresponding to higher pollen counts. These observations provided direct evidence of the allergenicity of airborne rice pollen in field conditions.  相似文献   
68.
There is increasing concern about the exposure to fungal aerosols in occupational environments and associated respiratory allergic diseases and asthma. A large number of people work in cattle sheds around the world, pulmonary function impairments and higher frequency of respiratory symptoms have been reported in dairy farmers; however, it appears that adequate information on the fungal aerosols from the cattle sheds are largely lacking. Volumetric assessment of airborne culturable and nonculturable fungal spores was performed in two sections of a large rural indoor cattle shed of West Bengal, India for 2 consecutive years. An Andersen Two Stage Viable Sampler was used for sampling culturable fungi and a Burkard Personal Slide Sampler was used to collect the total airborne fungal spores including both the culturable and nonculturable types. A total of 31 spore types and 35 types of viable colony-forming units were recorded. Average concentration range of total fungal spores was 233-2985/m(3) and concentration of viable colony-forming units ranged between 165 and 2225 CFU/m(3). Burkard Sampler showed higher frequencies of Aspergilli/Penicilli, Cladosporium, Alternaria, and smut spores. Andersen Sampler showed the prevalence of Aspergillus niger, Aspergillus flavus and Cladosporium cladosporioides colonies. Some recorded fungi were earlier reported as allergenic, toxic, and pathogenic for occupational workers as well as cattle population. Higher concentration levels of airborne total and culturable fungal spores were recorded during the months of November through February (winter) and June through September (late summer and rainy season).  相似文献   
69.
70.
There are important linkages between the health of humans and theenvironment, restoration of degraded lands, and long-term stewardship of public lands, yet most environmental indicators deal only with assessing the physical and biological aspects ofecosystems. In this article, we examine the ratings of perceptionsof several environmental problems for their utility as indicatorsof environmental quality, and examine perceptions of future land use by people interviewed in Santa Fe, New Mexico, near the Department of Energy's (DOE) Los Alamos National Laboratory (LANL). Overall, people with lower incomes rated environmental problems as more severe than others, were more willing to spend federal funds to solve them, and were consistent in their ratingsof severity of environmental problems and their willingness to spend federal funds. Cleaning up LANL and other Department of Energy sites, received the highest rating for expenditure of federal funds. The highest rated future uses for DOE sites were for recreation and for National Environmental Research Parks. People with less education generally gave higher ratings to mostfuture land uses for DOE than did those with more education. However, those with higher education gave higher ratings to nuclear reprocessing, and nuclear material storage. Where there were differences, the people interviewed at Santa Fe rated all environmental problems (except pesticides) as more severe than did those previously interviewed in Albuquerque (located fartherfrom the LANL site), and they were more willing to spend federalfunds on these problems. Ratings for all future land uses did notdiffer between the Santa Fe and Albuquerque respondents. These perception-based indicators show general agreement among peopleliving close and farther away from LANL with respect to cleaningup LANL and the future land uses for the site. These indicators should be considered by regulators, site personnel, and policy makers in future management and land use decisions.  相似文献   
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