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The deterioration of high quality waters has become an issue of great concern in China. The Chinese government has implemented a series of policies, laws and regulations to control water pollution and improve the surface water quality. However, these measures cannot fundamentally change the status of surface water pollution in China. Some high quality waters have been degraded and do not obtain effective protection. In this paper, we present our views that the lack of antidegradation policy restricts the protection of high quality waters in China. The viewpoint will be beneficial in solving the problem of water pollution in China and also to support other countries in their protection of high quality waters. 相似文献
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Stewart JR Vinjé J Oudejans SJ Scott GI Sobsey MD 《Applied and environmental microbiology》2006,72(2):1226-1230
Typing of F-specific RNA (FRNA) coliphages has been proposed as a useful method for distinguishing human from animal fecal contamination in environmental samples. Group II and III FRNA coliphages are generally associated with human wastes, but several exceptions have been noted. In the present study, we have genotyped and partially sequenced group III FRNA coliphage field isolates from swine lagoons in North Carolina (NC) and South Carolina (SC), along with isolates from surface waters and municipal wastewaters. Phylogenetic analysis of a region of the 5' end of the maturation protein gene revealed two genetically different group III FRNA subclusters with 36.6% sequence variation. The SC swine lagoon isolates were more closely related to group III prototype virus M11, whereas the isolates from a swine lagoon in NC, surface waters, and wastewaters grouped with prototype virus Q-beta. These results suggest that refining phage genotyping systems to discriminate M11-like phages from Q-beta-like phages would not necessarily provide greater discriminatory power in distinguishing human from animal sources of pollution. Within the group III subclusters, nucleotide sequence diversity ranged from 0% to 6.9% for M11-like strains and from 0% to 8.7% for Q-beta-like strains. It is demonstrated here that nucleotide sequencing of closely related FRNA strains can be used to help track sources of contamination in surface waters. A similar use of phage genomic sequence information to track fecal pollution promises more reliable results than phage typing by nucleic acid hybridization and may hold more potential for field applications. 相似文献
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Sequence Variation among Group III F-Specific RNA Coliphages from Water Samples and Swine Lagoons
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Jill R. Stewart Jan Vinj Sjon J. G. Oudejans Geoff I. Scott Mark D. Sobsey 《Applied microbiology》2006,72(2):1226-1230
Typing of F-specific RNA (FRNA) coliphages has been proposed as a useful method for distinguishing human from animal fecal contamination in environmental samples. Group II and III FRNA coliphages are generally associated with human wastes, but several exceptions have been noted. In the present study, we have genotyped and partially sequenced group III FRNA coliphage field isolates from swine lagoons in North Carolina (NC) and South Carolina (SC), along with isolates from surface waters and municipal wastewaters. Phylogenetic analysis of a region of the 5′ end of the maturation protein gene revealed two genetically different group III FRNA subclusters with 36.6% sequence variation. The SC swine lagoon isolates were more closely related to group III prototype virus M11, whereas the isolates from a swine lagoon in NC, surface waters, and wastewaters grouped with prototype virus Q-beta. These results suggest that refining phage genotyping systems to discriminate M11-like phages from Q-beta-like phages would not necessarily provide greater discriminatory power in distinguishing human from animal sources of pollution. Within the group III subclusters, nucleotide sequence diversity ranged from 0% to 6.9% for M11-like strains and from 0% to 8.7% for Q-beta-like strains. It is demonstrated here that nucleotide sequencing of closely related FRNA strains can be used to help track sources of contamination in surface waters. A similar use of phage genomic sequence information to track fecal pollution promises more reliable results than phage typing by nucleic acid hybridization and may hold more potential for field applications. 相似文献
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Andrés Cózar Marina Sanz-Martín Elisa Martí J. Ignacio González-Gordillo Bárbara Ubeda José á. Gálvez Xabier Irigoien Carlos M. Duarte 《PloS one》2015,10(4)
Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. 相似文献
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Triapitsyna GA Tarasova SP Atamaniuk NI Osipov DI Priakhin EA 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2012,52(3):298-304
The combined effect of acute gamma-irradiation at doses of 0, 50, 100, 150 and 200 Gy and nitrates in concentrations of 0.04 g/dm3 (that corresponds to maximum permissible concentrations for fishery waters), 0.1, 0.25, 0.5, 1.0, 2.5 g/dm3 (that is close to NO3(-) level in water of a reservoir R-17 used as radioactive waste storage of the "Mayak" Production Association) and 5.0 g/dm3 (that is close to NO3(-) level in the water of radioactive waste storage reservoir R-9) on the unicellular green algae Scenedesmus quadricauda growth has been studied in laboratory conditions. It was shown that the joint effects of nitrates and y-radiation had an antagonistic character. Thus, it may be concluded that chemical pollution is the factor limiting the development of green algae in reservoir R-17; probably, both factors, chemical and radiating, are essential to the algocenosis degradation in reservoir R-9. 相似文献
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Many of the directives that relate to the prevention of pollution or the improvement of fresh water also relate to lake waters since lake waters ultimately inherit much of the pollution that enters into fresh water. In order to determine the influence of the water depth on Clostridium perfringens, we utilised a new medium, lactose-sulfite (LS) broth, suggested for rapid enumeration and identification of C. perfringens. Duplicate samples were collected at each one of the following sites of the polluted station: surface, 60 cm, 90 cm and bottom (1.18 cm). Membrane filtration equipment was used. All samples were alternatively passed through two membrane filters, the first (20-25 microm pore size) was used for retention of the abundant phytoplankton and the second (porosity 0.45 microm) for C. perfringens. Membranes were placed into the first tube of ten-fold dilutions from 10(1) to 10(4) and incubated aerobically in a waterbath at 46 degrees C for 24 h. The numbers of C. perfringens fluctuated depending on the water depth. Vegetative forms were found only in the bottom sampling; they were never found in surface, 60 cm and 90 cm sampling sites. Sporulated forms were found in all sampling sites with the exception of the surface sampling. Clostridium perfringens as an anaerobic bacterium never occurred in the surface waters in vegetative or spore forms, even if the waters were extremely polluted by domestic or industrial activities. Vegetative forms occurred only in the bottom samples but spore forms which are more resistant to various environmental effects occurred in all depths except for the surface. 相似文献
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农业面源污染对水体富营养化的影响及其防治措施 总被引:203,自引:5,他引:198
随着点源污染得到逐步的治理,农业面源污染已成为水体富营养化的主要污染源,并引起了人们的极大关注,简要地概述了农业面源 水体富营养化中所起的重要作用,同时了国内外防治农业面源污染的主要措施,指出了防治农业面源污染的难点和建立稳定、和谐与良性循环的农业生态系统是治理农业面源污染的长久之针。 相似文献
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Vasil'eva AN Kruglov SV Koz'min GV Latynova NE Kvasnikova IuV Vaĭzer VI Starkov OV 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2008,48(1):102-109
The objects of researches are the soil and wild vegetation in the region of the radioactive waste storage situation. In result of monitoring it was recognized 137Cs unlike 90Sr did not spread out of storage territory in spite of trench destruction and migration of radionuclides with surface and ground waters. The forms of 137Cs, 90Sr and natural radionuclide 226Ra in soils and coefficients of 90Sr accumulation for the different kinds of plants growing at the territory of storage and 50-m zone around it were researched. The low specific activities of mobile forms of 90Sr were recognized for samples of soils selected from lowland by the terrace. The considerable differences were found for specific activities of radionuclides for different soil layers. Essential irregularity of soil surface and vegetation contamination at the test points disposed at a short distances from each other also was found. The interpretation of obtained results is presented. 相似文献
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This article is a review the recent results of research in the accumulation of natural and artificial radionuclides in birds from Russia (Adigea, Krasnodar, Rostov, Astrahan and Moscow regions, Novaya Zemlya isles), Ukraine, Vietnam, Poland, Ethiophia and Mongolia after global precipitation and local pollution, such as in the East-Urals radioactive region and radioactive zones after the Chernobyl accident. Resident birds reflect local level of radionuclide contamination. The 90Sr concentration in the food of the Pied Flycatcher had a tendency to increase in dependent of age. The Common Jay and the Mallard were the most contaminated with 137Cs in the Bryansk region. The total content of various radio-isotopes of plutonium in bird bones from Southwest Russia were hundred and thousand times more, than in Mongolia. Activity levels in specimens from Ethiopia bear record to Ethiopia can notbe a "pure" control site in radioecological research and radioactive background since it does not significantly differ from Turkmenia and Mongolia. 相似文献
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The North York Moors National Park, in Northeast England, is one of the few upland areas of the United Kingdom located immediately downwind of major sulphur and nitrogen emission sources. Despite this, few studies of air pollution impacts have been undertaken, and there is no formal long-term upland water quality monitoring site. We examined the condition of surface waters in the National Park based on (1) a unique 20 year stream pH record from three locations; and (2) a snapshot survey of 51 surface waters draining moorland and conifer plantations. Interpretation was supported by sulphur isotope analysis of a subset of water samples, and a diatom survey of one of the monitoring streams. Long-term pH data for a stream draining the peat plateau demonstrate extreme, year-round acidification, with recovery only evident in the last few years. Lower-elevation sites are less acidic, but show similar temporal trends, and are characterised by frequent and severe acid episodes. The snapshot survey confirmed that acidification of the moorland area is widespread, to a degree observed in few other areas globally; out of 37 moorland streams sampled, 32 had an acid neutralising capacity (ANC) below −50 μequiv. l−1. Sulphate was found to be (by far) the dominant cause of acidification, and sulphur isotope analysis confirmed that this derives primarily from atmospheric deposition. Nitrate concentrations remain low, indicating that the organic moorland soils continue to retain most incoming nitrogen. It appears that conifer planting has exacerbated acidification, leading to fivefold higher nitrate and threefold higher aluminium concentrations compared to the moorland sites. Available biological data suggest that waters in the region have been impoverished by acidification. We speculate that the slow recovery of surface waters in the North York Moors is due to the release of a legacy of stored sulphur from the peats, released during droughts. We conclude that: (1) acidification is far from being a solved problem in this sensitive near-source upland region, despite reductions in sulphur deposition; (2) plantation forestry has exacerbated the effects of atmospheric pollution, and triggered nitrogen saturation; (3) the lack of any formal long-term monitoring in the North York Moors represents a major gap in the current evidence base for the effects of long-range air pollutants on UK upland ecosystems. 相似文献
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In the absence of water-quality data, a biological indicator is the only way to estimate the pollution level. Samples of macrophytes from exposed shallow rocky substrata of the region of Algiers (Algeria, Mediterranean Sea) were collected in supposedly (in the absence of available pollution data) polluted and pristine waters. These samples were compared to a set of samples spanning a known pollution gradient found near Marseilles (France) and to some samples from a variety of other Mediterranean localities. All samples were collected in similar conditions. The diversity point (i.e., the number of species per sample) was not greater at Cherchell (control site) than at the three sites in the Bay of Algiers. Analysis of the dataset was successful in ranking the Algerian sites, but failed to calibrate the pollution level of the Algerian sites by inserting Algerian samples within the pollution gradient of Marseilles. In contrast, regional characteristics of the macrophyte communities appear to be largely prevalent. This means that water-quality biological indicators and indices based upon marine macrophytes, at least for the open waters and exposed shallow Mediterranean habitats studied here, could be reliable within a given region, but may require validation and/or adjustment, perhaps considerable, for other regions. 相似文献
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Stewart-Pullaro J Daugomah JW Chestnut DE Graves DA Sobsey MD Scott GI 《Journal of applied microbiology》2006,101(5):1015-1026
AIMS: The utility of coliphages to detect and track faecal pollution was evaluated using South Carolina surface waters that exceeded State faecal coliform standards. METHODS AND RESULTS: Coliphages were isolated from 117 surface water samples by single agar layer (SAL) and enrichment presence/absence (EP/A) methods. Confirmed F+ RNA coliphages were typed for microbial source tracking using a library-independent approach. Concentrations of somatic coliphages using 37 and 44.5 degrees C incubation temperatures were found to be significantly different and the higher temperature may be more specific for faecal contamination. The EP/A technique detected coliphages infecting Escherichia coli Famp in 38 (66%) of the 58 surface water samples negative for F+ coliphages by the SAL method. However, coliphages isolated by EP/A were found to be less representative of coliphage diversity within a sample. Among the 2939 coliphage isolates tested from surface water and known source samples, 813 (28%) were found to be F+ RNA. The majority (94%) of surface water F+ RNA coliphage isolates typed as group I. Group II and/or III viruses were identified from 14 surface water stations, the majority of which were downstream of wastewater discharges. These sites were likely contaminated by human-source faecal pollution. CONCLUSIONS: The results suggest that faecal contamination in surface waters can be detected and source identifications aided by coliphage analyses. SIGNIFICANCE AND IMPACT OF THE STUDY: This study supports the premise that coliphage typing can provide useful, but not absolute, information to distinguish human from animal sources of faecal pollution. Furthermore, the comparison of coliphage isolation methods detailed in this study should provide valuable information to those wishing to incorporate coliphage detection into water quality assessments. 相似文献
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Van 'T Zelfde M Tamis WL Vijver MG De Snoo GR 《Communications in agricultural and applied biological sciences》2011,76(4):867-877
Compared with other European countries, Dutch consumption of pesticides is high, particularly in agriculture, with many of the compounds found in surface waters in high concentrations and various standards being exceeded. Surface water quality is routinely monitored and the data obtained are published in the Dutch Pesticides Atlas. One important mechanism for reducing pesticide levels in surface waters is authorisation policy, which proceeds on the assumption that the pollution concerned has taken place in the Netherlands. The country straddles the delta of several major European rivers, however, and as river basins do not respect national borders some of the water quality problems will derive from neighbouring countries. Against this background the general question addressed in this article is the following: To what extent do countries neighbouring on the Netherlands contribute to pesticide pollution of Dutch surface waters? To answer this question, data from the Pesticides Atlas for the period 2005-2009 were used. Border zones with Belgium and Germany were defined and the data for these zones compared with Dutch data. In the analyses, due allowance was also made for authorised and non-authorised compounds and for differences between flowing and stagnant waters. Monitoring efforts in the border zones and in the Netherlands were also characterised, showing that efforts in the former are similar to those in the rest of the country. In the border zone with Belgium the relative number of non-authorised pesticides exceeding the standards is clearly higher than in the rest of the Netherlands. These exceedances are observed mainly in flowing waters. In contrast, there is no difference in the relative number of standard-exceeding measurements between the border zones and the rest of the Netherlands. In the boundary zones the array of standard-exceeding compounds clearly deviates from that in the rest of the Netherlands, with compounds authorised in the neighbouring countries but not in the Netherlands, such as flufenacet, featuring prominently. The share of the neighbouring countries in the total number of exceedances in the Netherlands is roughly proportional to the relative area of the border zones. Although there is a certain influx of pesticides from across national borders, the magnitude of the problem appears to be limited. 相似文献
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Strains of Aeromonas spp. (883) were isolated from 10 stations in the north-west of Spain. Biotyping of the strains gave: 55% Aeromonas caviae , 34% A. hydrophila , 6% A. sobria and 5% Aeromonas spp. Phenotypic characters that have been claimed to be related to virulence such as haemolysis and the Voges-Proskauer reaction were detected mostly in A. hydrophila and A. sobria. The distribution of the species was significantly related to levels of faecal pollution in waters. Aeromonas caviae predominated in sewage and waters with a high degree of faecal pollution. In less polluted waters, either fresh or marine, A. caviae and A. hydrophila were almost equally distributed. In waters with low or no faecal pollution, the proportion of A. sobria to other species increased considerably. 相似文献
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水田土壤溶液磷氮的动态变化及潜在的环境影响 总被引:24,自引:0,他引:24
通过模拟试验装置定位研究了稻-麦轮作条件下稻季土壤溶液的磷、氮含量变化,结果表明:(1)在施肥后的60d内田面水溶解性总磷(DTP)含量受施肥量的影响.尤其是施肥后10d内是磷素流失的高风险期;(2)磷的垂直渗漏(70cm深处)高峰发生在施肥后3~10d时期.渗漏量和施肥晕的关系不明显.磷在两个稻季的平均渗漏损失量分别为0.11、0.071kg/hm^2;地下排水会增加磷的垂卣渗漏;磷在表层、20、40、60、70cm土层土壤水中的含量基本呈下降趋势;(3)田面水溶解性总氮(DTN)含量在施肥后10d内受施肥量的影响;(4)氮的渗漏以NO3^-为主,两个稻季氮的平均渗漏损失量分别为3.2~4.5、4.6~28.0kg/hm^2.高量磷肥会减少氮的渗漏,土壤中原有的和施入的氮素在整个稻季均存在随地表径流和渗漏流失从而污染地表水和地下水的风险。总之无论氮素或磷素.施肥后10d内的田间管理是防止流失最关键的时期。 相似文献
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Strains of Aeromonas spp. (883) were isolated from 10 stations in the north-west of Spain. Biotyping of the strains gave: 55% Aeromonas caviae, 34% A. hydrophila, 6% A. sobria and 5% Aeromonas spp. Phenotypic characters that have been claimed to be related to virulence such as haemolysis and the Voges-Proskauer reaction were detected mostly in A. hydrophila and A. sobria. The distribution of the species was significantly related to levels of faecal pollution in waters. Aeromonas caviae predominated in sewage and waters with a high degree of faecal pollution. In less polluted waters, either fresh or marine, A. caviae and A. hydrophila were almost equally distributed. In waters with low or no faecal pollution, the proportion of A. sobria to other species increased considerably. 相似文献
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Background
Surface waters quality has declined in developing countries due to rapid industrialization and population growth. The microbiological quality of river Ganga, a life-sustaining surface water resource for large population of northern India, is adversely affected by several point and non-point sources of pollution. Further, untreated surface waters are consumed for drinking and various household tasks in India making the public vulnerable to water-borne diseases and outbreaks. Enterococci, the 'indicator' of water quality, correlates best with the incidence of gastrointestinal diseases as well as prevalence of other pathogenic microorganisms. Therefore, this study aims to determine the distribution of species diversity, dissemination of antimicrobial-resistance and virulence-markers in enterococci with respect to rural-urban landscape along river Ganga in northern India. 相似文献20.
贵州是我国汞矿的主要产地,其储量和产量均居全国首位,因此造成了该区域环境受到广泛的汞污染。从大的区域尺度上研究汞的污染分布特征对于了解该区域汞的污染现状有很好的指导作用。通过对贵州省汞污染源及各环境介质中汞污染情况的调查,首先阐释了万山、务川、滥木厂等几个主要汞矿区及燃煤和有机化工等行业的汞污染现状;并从大气、土壤和水体等环境介质方面综合分析了贵州地区汞的暴露水平与分布特征;采用ArcGIS 10.0描绘了各环境介质中总汞及甲基汞的分布特征。结果表明贵州省东北部与西南部汞矿区汞污染程度较高,大气、土壤和水体中的总汞分布呈明显的区域性,汞矿毗邻区域明显高于其他区域,矿区和城镇水体中甲基汞浓度较高,表明汞矿区和人为活动等因素影响水体中的甲基汞的分布。 相似文献