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1.
The spores of Cladosporium spp. and Alternaria spp., commonly described as the most allergenic spores, were collected by means of Durham gravimetric sampler from the Sivrihisar (Eskisehir) atmosphere throughout 2005 to 2006. The weekly variations in spores/cm(2) of Cladosporium and Alternaria were recorded. During this period, a total of 6,198 spores belonging to Cladosporium spp. and Alternaria spp. were recorded. Of these spores, 2,969 were identified in 2005 and 3,229 in 2006. While 69.55% of the total spores were those of Cladosporium spp., 30.45% were Alternaria spp. Relationships between airborne fungal spore presence and weather conditions were examined statistically. A Shapiro-Wilk test revealed that the airborne spores of Cladosporium spp. and Alternaria spp. had a normal distribution. Following this, Chi-square test, t test and Pearson correlation analysis were performed. The effects of temperature and relative humidity on the spore numbers of Cladosporium spp. and Alternaria spp. were significant according to the month in which they were collected (p < 0.01). The spore concentrations of each species reached to their highest levels in June 2006.  相似文献   

2.
Alternaria and Cladosporium, known as the most allergenic spores were first collected by means of Durham gravimetric sampler from Eskisehir atmosphere from January 1, 2000 to December 31, 2001. The daily, monthly and annual variations in spores/cm(2) of Cladosporium and Alternaria were recorded. During this period, a total of 10.231 spores belonging to Cladosporium and Alternaria genera were recorded. Of these spores, 5,103 were identified in 2000 and 5,128 in 2001. While 63.09% of the total spores were those of Cladosporium, 36.91% were of Alternaria. Relationships between airborne fungal spore presence and meteorological conditions were statistically investigated. A Shapiro-Wilk test revealed that the airborne Cladosporium and Alternaria spores differed from a normal distribution. Thus, a Friedmann test was performed followed by a Pearson Correlation Analysis. The effects of rainfall, temperature and wind speed on Cladosporium and Alternaria numbers were non-significant according to the sites and months (p > 0.05), but the effects of relative humidity on Cladosporium and Alternaria numbers were significant (p < 0.01). Spore concentrations reached to their highest levels in May 2001.  相似文献   

3.
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   

4.
Fungal spores are a significant fraction of the atmospheric bioparticles (bioaerosols) and many species are capable of inducing the production of specific immunoglobulin E (IgE), aggravating the clinical symptoms of allergic respiratory diseases in sensitized individuals. The aim of this work was to evaluate the distribution of potentially allergenic Pleosporales spores in two locations with different urbanization indexes, characterizing its seasonal pattern. The seasonal distribution of several spore types belonging to the Pleosporales (Alternaria, Drechslera, Epicoccum, Paraphaeosphaeria, Pithomyces, Pleospora and Stemphylium) in Amares (rural area) and Porto (urban area) was continually studied from January 2005 to December of 2007, using Hirst-type volumetric spore traps. Alternaria was the most abundant fungal spore type found in the atmosphere of Amares and Porto. This fungal type, together with Drechslera, Epicoccum, Pithomyces and Stemphylium, was mainly present during summer. Nevertheless, Leptosphaeria, Pleospora and Venturia spores were detected during winter and spring, while Paraphaeosphaeria spores were also observed during summer and autumn. These different seasonal patterns were responsible for the expansion of the exposure period for the Alt a 1 allergen. The concentration of the studied spore types was higher in the rural area than in the urban one, with exception for Pleospora and Drechslera. According to the correlations with meteorological factors, the selected fungal spores can be divided into two groups: (i) Alternaria, Drechslera, Epicoccum, Pithomyces and Stemphylium presented positive correlations with temperature and negative correlations with relative humidity and rainfall; (ii) Leptosphaeria, Paraphaeosphaeria, Pleospora and Venturia presented a contrary behavior. Usually, the occurrence of the Alt a 1 allergen has been associated with the presence of airborne Alternaria spores; the present work follows the seasonal distribution of other fungal spore species known to contain this molecule. The widespread occurrence of Alt a 1 plays an important role in the incidence and aggravation of allergic disorders.  相似文献   

5.
Airborne fungal spores are well known to cause respiratory allergic diseases particularly bronchial asthma, allergic rhinitis, rhino-conjunctivitis and allergic broncho-pulmonary aspergillosis in both adults and children. In order to monitor and analyze airborne fungal flora of the Karachi environment, an aeromycological study was conducted using a Burkard 7-Day Recording Volumetric Spore Trap from January to December 2010. The data recorded from the Spore Trap was further analyzed for percent catch determination, total spores concentration, seasonal periodicities and diurnal variations. Cladosporium spp (44.8%), Alternaria spp. (15.5%), Periconia spp (6.1%), Curvularia spp (2.1%), Stemphylium spp (1.3%) and Aspergillus/Penicillium type (1%) emerged to be major components constituting more than 70% of the airborne fungal flora. Cladosporium, Curvularia and Stemphylium displayed a clear seasonal trend, while there were no clear seasonal trends for other fungal spore types. Diurnal variations were observed to be mainly having daytime maxima. Spearman Rank Correlation Coefficient analysis was conducted using various weather parameters. The various fungal types showed a negative correlation with heat index, dew point, wind velocity and wind chill. However, a positive correlation was found with humidity, rain and barometric pressure. In fact, Alternaria, Bipolaris and Periconia showed a negative correlation with temperature, while Cladosporium and Periconia showed a negative correlation with heat index, dew point, wind velocity and wind chill. The barometric pressure was positively correlated with Cladosporium. On the basis of these findings, it can be concluded that a number of fungal spores are present in the atmosphere of Karachi throughout the year, with certain atmospheric conditions influencing the release, dispersion, and sedimentation processes of some genera. It is expected that clinicians will use the identified fungal flora for diagnosis and treatment and/or adopt preventative measures for allergic individuals.  相似文献   

6.
Cladosporium is one of the most common airborne molds found in indoor and outdoor environments. Cladosporium spores are important aeroallergens, and prolonged exposure to elevated spore concentrations can provoke chronic allergy and asthma. To accurately quantify the levels of Cladosporium in indoor and outdoor environments, two real-time PCR systems were developed in this study. The two real-time PCR systems are highly specific and sensitive for Cladosporium detection even in a high background of other fungal DNAs. These methods were employed to quantify Cladosporium in aerosols of five different indoor environments. The investigation revealed a high spore concentration of Cladosporium (10(7) m(-3)) in a cow barn that accounted for 28-44% of the airborne fungal propagules. In a countryside house that uses firewood for heating and in a paper and pulp factory, Cladosporium was detected at 10(4) spores m(-3), which accounted for 2-6% of the fungal propagules in the aerosols. The concentrations of Cladosporium in these three indoor environments far exceeded the medical borderline level (3000 spores m(-3)). In a power station and a fruit and vegetable storage, Cladosporium was found to be a minor component in the aerosols, accounted for 0.01-0.1% of the total fungal propagules. These results showed that monitoring Cladosporium in indoor environments is more important than in outdoor environments from the public health point of view. Cladosporium may not be the dominant fungi in some indoor environments, but its concentration could still be exceeding the threshold value for clinical significance. The methods developed in this study could facilitate accurate detection and quantification of Cladosporium for public health related risk assessment.  相似文献   

7.
A survey to assess the occurrence of airborne fungal spores in three different industries, dairies, carpentries and greenhouses, was carried out. The results revealed considerable fungal pollution in the environments of the industries sampled. Noteworthy was the occurrence of fungal genera frequently implicated in allergic and non-allergic diseases, or well known for the production of mycotoxins in foods or characterized by a marked degradative activity on different substrata. Penicillium, Candida, Mucor and Geotrichum were the most common genera identified in the dairies; Penicillium, Cladosporium, yeasts, Trichoderma and Rhizopus occurred more frequently in the carpentries; Cladosporium, Alternaria, Penicillium and Stemphilium were prevailing in the greenhouse.The results of our survey support the idea that, due to their high incidence and variety, fungal spores may represent a potential health hazard in working environments, where their concentration can be affected by many operations and handling.  相似文献   

8.
In order to evaluate the impact of atmospheric pollutants emitted by the industrial settlement of Milazzo (Italy) on agriculture, sulphur dioxide and ozone levels in air were monitored and the data were used to estimate yield losses of the most widespread cultures. Trace element concentrations in crops and soils were also detected and metabolic profiles of soil microbial communities were considered. Vibrio fischeri test was used to appraise airborne pollutant ecotoxicity and epidemiological studies on causes of death distribution were carried out to characterize health state of people living in the area. All the sampling points were selected in farms on the basis of a theoretical meteo-diffusive model of industrial air pollutants. Experimental SO2 and O3 values mainly exceeded the threshold established by Italian and EU regulations to protect vegetation and they correspond to estimated significant crop losses. Conversely toxic element residues in soils and in agroalimentary products were generally lower than the fixed values. SO2 and O3 concentrations, toxic element contents and ecotoxicity levels of airborne pollutants were not related only to industrial site emissions, while the fluctuations on metabolic profiles of soil microbial communities seem to agree with the predicted deposition of xenobiotic compounds from the industrial plants. The epidemiological study evidenced a better health state of populations living in the investigated area than in the Messina province and the Sicily region but, inside the area, males living in the municipalities closest to the industrial settlement exhibited a worst health state than those in the very far ones.  相似文献   

9.
Increasing concentrations of atmospheric carbon dioxide CO2 have a beneficial effect on crop production that would tend to offset some of the economic losses that might be generated in some areas by the climatic effects of atmospheric CO2 and other greenhouse gases. Previous estimates of the economic benefits of CO2 fertilization on world crop production, however, were based on the assumption that percent changes in supply are equal to percent changes in yield. This assumption is not valid, however, because it confounds changes in supply with changes in quantity supplied. This error leads to an overestimation of the real economic benefits of CO2 fertilization by 61–166%. The effects of CO2 fertilization on crop production, therefore, will reduce some of the potential damages caused by the climatic impacts of greenhouse gases, but by significantly less than that indicated in earlier research.  相似文献   

10.
空气微生物污染的监测及研究进展   总被引:4,自引:0,他引:4       下载免费PDF全文
空气微生物不但与环境空气质量、空气污染和人体健康密切相关,并且还与自然生态平衡及许多生命现象直接相关,在自然界的物质循环中起着非常重要的作用。文章从空气微生物的污染现状、采样方法、粒度分布、分离鉴定、微生物评价、时空分布等方面对空气微生物的研究现状进行了综述,并对空气微生物在环境监测中的研究和前景进行了展望,建议空气微生物污染监测应常态化,应控制和开展对大气细颗粒或超细颗粒物对人体健康的影响研究。  相似文献   

11.
Advances in polymerase chain reaction (PCR) have permitted accurate, rapid and quantitative identification of microorganisms in pure cultures regardless of viability or culturability. In this study, a simple sample processing method was investigated for rapid identification and quantification of fungal spores from dust samples using both conventional and real-time PCR. The proposed method was evaluated for susceptibility to interference from environmental dust samples. Stachybotrys chartarum and Aspergillus fumigatus were used as test organisms. The sensitivity of detection in pure culture was 0.1 spore DNA equivalents per PCR reaction corresponding to 20 spores ml(-1) in the sample. However, 1 spore DNA equivalent per PCR reaction corresponding to 200 spores ml(-1) in the sample was the lowest amount of spores tested without interference in dust samples spiked with spores of either fungal species. The extent of inhibition was calculated using conventional and real-time PCR reactions containing fungal spores, specific primers, specific probes (for real-time PCR) and various amounts of dust. The results indicate that the extent of inhibition by dust on PCR varies with the type and amount of dust, and number of spores. No interference in the analysis of spiked samples was detected from 0.2 mg ml(-1) of four real-life dust samples at p-value >0.05 using 2 x 10(4) spores for conventional PCR and 2 x 10(5) spores for real-time PCR. However, samples containing >0.2 mg ml(-1) real-life dust compromised the PCR assay. These results suggest the potential usefulness of a simple sample processing method in conjunction with PCR for monitoring the fungal content of aerosols collected from indoor environments.  相似文献   

12.
Personal aerosol samplers are widely used to monitor human exposure to airborne materials. For bioaerosols, interest is growing in analyzing samples using molecular and immunological techniques. This paper presents a personal sampler that uses a two-stage cyclone to collect bioaerosols into disposable 1.5 ml Eppendorf-type microcentrifuge tubes. Samples can be processed in the tubes for polymerase chain reaction (PCR) or immunoassays, and the use of multiple stages fractionates aerosol particles by aerodynamic diameter. The sampler was tested using fluorescent microspheres and aerosolized fungal spores. The sampler had first and second stage cut-off diameters of 2.6 microm and 1.6 microm at 2 l min(-1)(geometric standard deviation, GSD = 1.45 and 1.75), and 1.8 microm and 1 microm at 3.5 l min(-1)(GSD = 1.42 and 1.55). The sampler aspiration efficiency was >or=98% at both flow rates for particles with aerodynamic diameters of 3.1 microm or less. For 6.2 microm particles, the aspiration efficiency was 89% at 2 l min(-1) and 96% at 3.5 l min(-1). At 3.5 l min(-1), the sampler collected 92% of aerosolized Aspergillus versicolor and Penicillium chrysogenum spores inside the two microcentrifuge tubes, with less than 0.4% of the spores collecting on the back-up filter. The design and techniques given here are suitable for personal bioaerosol sampling, and could also be adapted to design larger aerosol samplers for longer-term atmospheric and indoor air quality sampling.  相似文献   

13.
In this paper, I develop an optimization model for integrated coastal management in which decisions arise from an area-based algorithm that minimizes predicted damage caused by beach erosion and inshore flooding, while accounting for economic, social, and environmental losses. The model favors the involvement of stakeholders in coastal management, but does not use complicated assessment procedures for non-economic indicators or relative weights to combine economic, social, and environmental indicators. Instead, the integration between economic activities or properties and the environmental status and landscape is represented objectively and non-linearly by referring to initial and sustainability conditions, combined with budgetary and environmental constraints. The model successfully accounted for both human and environmental dynamics by depicting delayed effects, neighborhood externalities, and feedback effects. It calculated a single optimal value for each integrated coastal management strategy, which permitted the support of future decisions and the evaluation of past decisions. The model’s insights were based on reliable estimates, with reliability determined by calculating the confidence level. The model was successfully applied to Italy’s Comacchio coastal municipality, where it revealed the priorities for optimal beach nourishment, dune fixation, and residential and holiday housing development based on budget constraints, beach losses, flood damage, pollution impacts, and land-use constraints.  相似文献   

14.
In order to help guide air pollution legislation at the European level, harmful air pollution effects on agriculture crops and the consequent economic implications for policy have been studied for more than a decade. Ozone has been labeled as the most serious of the damaging air pollutants to agriculture, where growth rates and consequently yields are dramatically reduced. Quantifying the effects has formed a key factor in policymaking. Based on the widely held view that AOT40 (Accumulated exposure Over Threshold of 40 ppb) is a good indicator of ozone-induced damage, the Danish Eulerian Model (DEM) was used to compute reduced agriculture yields on a 50 km×50 km grid over Europe. In one set of scenarios, a ten year meteorological time series was combined with realistic emission inventories. In another, various idealized emission reduction scenarios are applied to the same meteorological time series. The results show substantial inter-annual variability in economic losses, due in most part to meteorological conditions which varied much more substantially than the emissions during the same period. It is further shown that, taking all uncertainties into account, estimates of ozone-induced economic losses require that a long meteorological record is included in the analysis, for statistical significance to be improved to acceptable levels for use in policy analysis. In this study, calculations were made for Europe as a whole, though this paper presents results relevant for Denmark.  相似文献   

15.
Cost-Benefit Analysis is a key tool for evaluating welfare gains or losses from an investment. It is now well established that environmental impacts are crucial to consider the full welfare implications of a project. Debate has focussed on approaches to improve the valuation of environmental impacts, and controversy in the discounting of future impacts to present values. The issue of the time horizon of analysis is frequently overlooked. The framing of the time horizon has major implications, as environmental costs and benefits often accrue in the long-term. The technical aspects of setting the time horizon are reviewed, along with updates to practice guidance, noting the longer time horizons now becoming typical. It is demonstrated that the time horizon can have a considerable impact on results, even more substantial than the discount rate. While uncertainty is noted as a technical challenge to longer-term analysis, the use of scenarios and sensitivity testing are noted as an appropriate response. For projects with long-term environmental effects, such as those related to air pollution, climate change and ecosystem damages, it is recommended to use timescales of 100+ years for economic evaluation of the impact. Failing to fully capture these long-term welfare gains and losses will distort analysis with a bias towards those projects that are more carbon-intensive, or environmentally damaging. Such a bias would undermine not only the evaluation, but welfare and sustainable development in general.  相似文献   

16.
In this study, the effect of relative humidity, temperature, and wind on airborne fungal allergens in the 11 different districts of Manisa City was investigated from January 2004 to December 2005. The aim of this study was to conduct a survey to get to know the relation between wind, temperature, and relative humidity and population of allergenic fungal spores in the atmosphere. A total of 792 samples were observed by using the Merck MAS100 air sampler and 12,988 fungal colonies were counted. Fourteen fungal genera could be determined; Cladosporium that was generally found as the predominant genus followed by Penicillium, Aspergillus, and Alternaria. During the entire study, seasonal variation was found to be related to atmospheric conditions especially. The optimal conditions of meteorological factors for the fungi growth resulted in the increased number of mycoflora, qualitatively and quantitatively.  相似文献   

17.
Although interdisciplinary collaboration to address a singleenvironmental problem is more common than in the past, all toooften the significant atmospheric problems of our day such asstratospheric ozone depletion, acidic deposition or climaticchange are addressed on a single issue basis. Systems analysis isa way of looking at a problem in a holistic, integrated fashionthrough including as many as practicable of the importantcomponents, and the linkages among them. Systems analysisoften begins with a conceptual model which, even if lackingquantification, is a useful means of changing ones thinking to amulti-issue approach. If possible, conceptual models areoperationalized by quantification (using the best availablescientific knowledge) of the stocks and flows of the relevantcomponents of the problem, and the processes that are involved.In this paper, a systems approach to food production is used tolink various atmospheric issues such as regional acidification andclimatic change. A spreadsheet model of food demand andproduction in various world regions examined the possible effectof atmospheric change on how much food we can grow, andwhether or not we may be able to meet the increased demand inthe year 2025. Using relatively modest changes in factors ofagricultural production, the spreadsheet model calculated globalshortfalls by the year 2025 of the order of 10 to 20% in someimportant agricultural crops, despite the improvements in cropproduction factors that are envisaged by the Food andAgricultural Organization from now until the year 2010, and thatwere extrapolated in this paper to 2025. The model alsocalculated that climatic change in combination with eithertropospheric ozone or increased UV-B radiation caused bydepletion of the stratospheric ozone layer may in general makethe situation worse than in the case of climatic change alone.Given the large uncertainties in the input data, the results in thispaper should not be viewed as predictions but rather as anexample of taking a relatively simple systems approach to foodproduction using a spreadsheet model, and calculating the effectsthat various aspects of atmospheric change might have upon it.Therefore, it is extremely important to know the effects uponcrop production factors of climatic change, tropospheric ozoneand increased UV-B radiation not only as individual issues, butalso of their combined effect since it is probable that in manyregions they will occur in combination.  相似文献   

18.
The concentrations and composition of airborne fungal spores in homes fitted with portable HEPA filtration units were examined to provide information to evaluate the importance of varying levels of fungal spores in residential environments in Perth, Australia. A novel method for simulating activity/impaction on carpeted environments was also investigated. Reductions in fungal (35%) and particulate (38%) levels were achieved in the air filter homes. Penicillium, Cladosporium and yeasts were the most common and widespread fungi recovered indoors and outdoors. Fungal range decreased over the study period but this could be due to an overall reduced dissemination of spores (less spores in the air).  相似文献   

19.
Nitrate leaching forms an important environmental problem because it causes pollution of groundwater and surface water, and adds to already problematic eutrophication. This study analyses the impact of reductions in nitrate leaching on land cover decisions of dairy farms, of which the activities make an important contribution to nitrate leaching. As the level of nitrate leaching depends on groundwater depth as well as on the supply of nitrogen, spatial variation in groundwater levels will cause a spatial variation in land cover under restrictions on nitrate leaching. A non-linear partial optimisation model for the economic and ecological aspects of the problem were used to show how land cover and dairy farms' financial balances change when nitrate losses are reduced. The model is spatially explicit, and describes nitrate leakage and yields of maize and grass as a function of groundwater depth, including the effects of various grazing systems. The model analyses the decisions of a risk neutral agent who minimises costs under the following constraints: (i) production, feed requirements and mass balances for fodder; (ii) constraints for nitrate leaching. Economic costs are attributed to increased costs of fodder and processing of manure when nitrate restrictions are tightened. An important result of the study is the variation in compliance costs and land cover for maize and grass production brought about by spatial variation in groundwater depth. While the effects are negligible for some shallow groundwater classes, it is extremely difficult in other classes – if not impossible – to obtain the EU standard of maximum admissible losses of 34 kg N ha–1 at low costs. The study shows an important reduction in land cover by maize.  相似文献   

20.
Feasibility of an irrigation project is evaluated by two criteria viz., reservoir capacity to irrigate its command area and economic returns by incremental crop production versus capital investment for dam construction. The annual water requirement of different crops in the command area is estimated and compared with the availability of water from the dam for irrigation purpose. The annual crop water requirement is estimated as the sum of evapotranspiration for crops and transmission and other losses. Evapotranspiration is estimated by modified Penman formula. Economics of crop production is analyzed by first estimating the monetary value of existing crop production under current rain fed conditions and then estimating the incremental production of irrigated command area for the proposed crop pattern. The proposed cropping pattern is prepared so as to maximize the benefit of crop production and fodder requirement while maintaining a better crop rotation to improve and maintain physical, chemical, and biological conditions of the soil. The dam is to be used for irrigation and water supply only. Command area served by this reservoir will be 76,500 ha. The existing annual agricultural return is Rs. 2995.56 lakhs and with the proposed irrigation scheme, it is estimated as Rs. 1,77,91.90 lakhs. The incremental annual return would be Rs. 1,47,96.35 lakhs i.e., 642.68% increase in annual return.  相似文献   

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