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851.
The raw water quality and associations between the factors considered as threats to water safety were studied in 20 groundwater supplies in central Finland in 2002-2004. Faecal contaminations indicated by the appearance of Escherichia coli or intestinal enterococci were present in five small community water supplies, all these managed by local water cooperatives. Elevated concentrations of nutrients in raw water were linked with the presence of faecal bacteria. The presence of on-site technical hazards to water safety, such as inadequate well construction and maintenance enabling surface water to enter into the well and the insufficient depth of protective soil layers above the groundwater table, showed the vulnerability of the quality of groundwater used for drinking purposes. To minimize the risk of waterborne illnesses, the vulnerable water supplies need to be identified and appropriate prevention measures such as disinfection should be applied.  相似文献   
852.
We analysed polychlorinated dibenzo-p-dioxins and furans (PCDD/F, dioxins), and polychlorinated biphenyls (PCB) in 13 fish meal, five fish oil, and seven fish feed samples. Polybrominated diphenyl ethers (PBDE), organotin compounds (OTC), and perfluoroalkylated substances (PFAS) were analysed in ten fish meal, two fish oil, and two fish feed samples. All measured TEQ concentrations of PCDD/F and PCB were below the maximum levels set by Directive 2002/32/EC. There was no correlation between concentrations of WHOPCDD/F-TEQ and indicator PCB in our samples. The most common congeners among PBDEs were BDE-47 and BDE-100. BDE-209 was present in five fish meals of the ten analysed. Tributyltin (TBT) was the predominant congener in all samples except in three fish meals, where monobutyltin (MBT) was the major congener. Perfluorooctane sulphonate (PFOS) was the predominant congener in six fish meals of the ten analysed. There was large variation in concentrations and congener distributions of the studied compounds between our samples. Our results underline a need to pay special attention to the origin and purity of feed raw material of marine origin.  相似文献   
853.
As one of the worlds’ most heavily applied herbicides, atrazine is still a matter of controversy. Since it is regularly found in ground and drinking water, as well as in sea water and the ice of remote areas, it has become the subject of continuous concern due to its potential endocrine and carcinogenic activity. Current findings prove long-held suspicions that this compound persists for decades in soil. Due to the high amount applied annually all over the world, the soil burden of this compound is considered to be tremendous, representing a potential long-term threat to the environment. The persistence of chemicals such as atrazine has long been underestimated: Do we need to reconsider the environmental risk?  相似文献   
854.
855.
Microbial particles can readily be released into the air from different types of man-made sources such as waste operations. Microbiological emissions from different biological sources and their dispersion may be an issue of concern for area planning and for nearby residents. This study was designed to determine the concentrations and diversity of microbiological emissions from four different man-made source environments: waste center with composting windrows, sewage treatment plant, farming environment, and cattle manure spreading. Samples of airborne particles were collected onto polyvinyl chloride filters at three distances along the prevailing downwind direction, from each source environment during a period of approximately 1 week. These samples were analyzed for 13 species or assay groups of fungi, bacterial genus Streptomyces, and Gram-positive and -negative bacteria using quantitative polymerase chain reaction (PCR). Samples for determining the concentrations of viable fungi and bacteria were collected from all environments using a six-stage impactor. The results show that there were variations in the microbial diversity between the source environments. Specifically, composting was a major source for the fungal genera Aspergillus and Penicillium, particularly for Aspergillus fumigatus, and for the bacterial genus Streptomyces. Although the microbial concentrations in the sewage treatment plant area were significantly higher than those at 50 or 200 m distance from the plant area, in the farming environment or cattle manure spreading area, no significant difference was observed between different distances from the source. In summary, elevated concentrations of microbes that differ from background can only be detected within a few hundred meters from the source. This finding, reported earlier for culturable bacteria and fungi, could thus be confirmed using molecular methods that cover both culturable and nonculturable microbial material.  相似文献   
856.
An analysis of seismic risk from a tourism point of view   总被引:1,自引:0,他引:1  
Mäntyniemi P 《Disasters》2012,36(3):465-476
Global awareness of natural calamities increased after the destructive Indian Ocean tsunami of December 2004, largely because many foreigners lost their lives, especially in Thailand. This paper explores how best to communicate the seismic risk posed by different travel destinations to crisis management personnel in tourists' home countries. The analysis of seismic risk should be straightforward enough for non-specialists, yet powerful enough to identify the travel destinations that are most at risk. The output for each location is a point in 3D space composed of the natural and built-up environment and local tourism. The tourism-specific factors can be tailored according to the tourists' nationality. The necessary information can be collected from various directories and statistics, much of it available over the Internet. The output helps to illustrate the overall seismic risk conditions of different travel destinations, allows for comparison across destinations, and identifies the places that are most at risk.  相似文献   
857.
Cell lines of Etroplus suratensis established in our laboratory were evaluated for their potential use as screening tools for the ecotoxicological assessment of tannery effluent. The cytotoxic effect of tannery effluent in three cell lines derived from eye, kidney and gill tissue of E. suratensis was assessed using multiple endpoints such as Neutral Red (NR) assay, Coomassie Blue (CB) protein assay and Alamar Blue (AB) assay. Acute toxicity tests on fish were conducted by exposing E. suratensis for 96 h to tannery effluent under static conditions. The toxic effect of tannery effluent on the survival of fish was found to be concentration and time dependent. The tannery effluent at the concentration of 15% caused 100% mortality at 96 h whereas the lower concentration (0.5%) caused 13.33% mortality. The cytotoxicity of tannery effluent was found to be similar in the three cell lines tested, independent of the toxic endpoints employed. EC50 values, the effective concentration of tannery effluent resulting in 50% inhibition of cytotoxicity parameters after 48 h exposure to tannery effluent were calculated for eye, kidney and gill cell lines using NR uptake, AB and cell protein assays. Statistical analysis revealed good correlation with r2 = 0.95-0.99 for all combinations between endpoints employed. Linear correlations between each in vitro EC50 and the in vivo LC50 data, were highly significant p < 0.001 with r2 = 0.977, 0.968 and 0.906 for AB50, NR50, and CB50, respectively.  相似文献   
858.
The recent claim made in this journal that nuclear bomb tests and the Chernobyl disaster caused distortions in the secondary sex ratio is shown to be a likely artifact of data mining, misused statistics, and misreading of the evidence. In particular, the concept of statistical “significance” and its limitations do not seem to be fully understood, and important confounding factors have not been accounted for.  相似文献   
859.
We summarize the patterns of 137Cs activity concentrations and transfer into fish and other biota in four small forest lakes in southern Finland during a twenty-year period following the Chernobyl accident in April 1986. The results from summer 1986 showed fastest accumulation of 137Cs into planktivorous fishes, i.e. along the shortest food chains. Since 1987, the highest annual mean values of 137Cs have been recorded in fish occupying the highest trophic levels, for perch (Perca fluviatilis) 13,600 Bq/kg (ww) and for pike (Esox lucius) 20,700 Bq/kg (ww). At the same time, activity concentrations of 137Cs in crustacean zooplankton and Asellus aquaticus have ranged between 1000 and 19,500 Bq/kg (dw). In 2006, 5-28% of the 1987 137Cs activity concentration levels were still present in perch and pike. Since 1989 their 137Cs activity concentrations in oligohumic seepage lakes have remained significantly higher than in polyhumic drainage lakes due to the increased transfer of 137Cs into fish in the seepage lakes with lower electrolyte concentrations, longer water retention times and lower sedimentation rate.  相似文献   
860.
ABSTRACT

The spatial variability of different fractions of particulate matter (PM) was investigated in the city of Basel, Switzerland, based on measurements performed throughout 1997 with a mobile monitoring station at six sites and permanently recorded measurements from a fixed site. Additionally, PM10 measurements from the following year, which were concurrently recorded at two urban and two rural sites, were compared.

Generally, the spatial variability of PM4, PM10, and total suspended particulates (TSP) within this Swiss urban environment (area = 36 km2) was rather limited. With the exception of one site in a street canyon next to a traffic light, traffic density had only a weak tendency to increase the levels of PM. Mean PM10 concentration at six sites with different traffic densities was in the range of less than ±10% of the mean urban PM10 level. However, comparing the mean PM levels on workdays to that on weekends indicated that the impact of human activities, including traffic, on ambient PM levels may be considerable.

Differences in the daily PM10 concentrations between urban and more elevated rural sites were strongly influenced by the stability of the atmosphere. In summer, when no persistent surface inversions exist, differences between urban and rural sites were rather small. It can therefore be concluded that spatial variability of annual mean PM concentration between urban and rural sites in the Basel area may more likely be caused by varying altitude than by distance to the city center.  相似文献   
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