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91.
92.
Information on the exposure of individual persons to radiofrequency (RF) fields is scarce, although such data are crucial in order to develop a suitable exposure assessment method, and frame the hypothesis and design of future epidemiological studies. The main goal of this survey is to assess individual RF exposure on a population basis, while clarifying the relative contribution of different sources to the total exposure. A total of 377 randomly selected people were analyzed. Each participant was supplied with a personal exposure meter for 24-hour measurements (weekday), and kept a time–location–activity diary. Electric field strengths were recorded in 12 different RF bands every 13 s. Summary statistics were calculated with the robust regression on order statistics method. Most of the time, recorded field strengths were not detectable with the exposure meter. Total field, cordless phones, WiFi-microwave, and FM transmitters stood apart with a proportion above the detection threshold of 46.6%, 17.2%, 14.1%, and 11.0%, respectively. The total field mean value was 0.201 V/m, higher in urban areas, during daytime, among adults, and when moving. When focusing on specific channels, the highest mean exposure resulted from FM sources (0.044 V/m), followed by WiFi-microwaves (0.038 V/m), cordless phones (0.037 V/m), and mobile phones (UMTS: 0.036 V/m, UMTS: 0.037 V/m). Various factors, however, contributed to a high variability in RF exposure assessment. These population-based estimates should therefore be confirmed by further surveys to better characterize the exposure situation in different microenvironments.  相似文献   
93.
Different water Acts (e.g., the European Water Framework Directive) and stakeholders involved in aquatic affairs have promoted integrated river basin management over recent decades. However, few studies have provided feedback on these policies. The aim of the current article is to fill this gap by exploring how local newspapers reflect the implementation of a broad public participation within a catchment of France known for its innovation with regard to this domain. The media coverage of a water management strategy in the Drôme watershed from 1981 to 2008 was investigated using a content analysis and a geographic information system. We sought to determine what public participation and decentralized decision-making can be in practice. The results showed that this policy was integrated because of its social perspective, the high number of involved stakeholders, the willingness to handle water issues, and the local scale suitable for participation. We emphasized the prominence of the watershed scale guaranteed by the local water authority. This area was also characterized by compromise, arrangements, and power dynamics on a fine scale. We examined the most politically engaged writings regarding water management, which topics of each group emphasized, and how the groups agreed and disagreed on issues based on their values and context. The temporal pattern of participation implementation was progressive but worked by fits and starts.  相似文献   
94.
Environmental Science and Pollution Research - Freshwater contamination by pesticides in agricultural landscapes is of increasing concern worldwide, with strong pesticide impacts on biodiversity,...  相似文献   
95.
Nickel–metal hydride (NiMH) batteries contain high amount of industrial metals, especially iron, nickel, cobalt and rare earth elements. Although the battery waste is a considerable secondary source for metal and chemical industries, a recycling process requires a suitable pretreatment method before proceeding with recovery step to reclaim all valuable elements. In this study, AA- and AAA-type spent NiMH batteries were ground and then sieved for size measurement and classification. Chemical composition of the ground battery black mass and sorted six different size fractions were determined by an analytical technique. Crystal structures of the samples were analyzed by X-ray diffraction. Results show that after mechanical treatment, almost 87 wt% of the spent NiMH batteries are suitable for further recycling steps. Size classification by sieving enriched the iron content of the samples in the coarse fraction which is bigger than 0.25 mm. On the other hand, the amounts of nickel and rare earth elements increased by decreasing sample size, and concentrated in the finer fractions. Anode and cathode active materials that are hydrogen storage alloy and nickel hydroxide were mainly collected in finer size fraction of the battery black mass.  相似文献   
96.
Bioleaching processes have been demonstrated to be effective technologies in removing heavy metals from wastewater sludge, but long hydraulic retention times are typically required to operate these bioprocesses. A hybrid process (coupling biological and chemical processes) has been explored in laboratory pilot-scale experiments for heavy metals (cadmium [Cd], copper [Cu], chromium [Cr], and zinc [Zn]) removal from three types of sludge (primary sludge, secondary activated sludge, and a mixture of primary and secondary sludge). The hybrid process consisted of producing a concentrate ferric ion solution followed by chemical treatment of sludges. Ferric iron solution was produced biologically via oxidation of ferrous iron by A. ferrooxidans in a continuous-flow stirred tank (5.2 L) reactor (CSTR). Wastewater sludge filtrate (WSF) containing nutrients (phosphorus and nitrogen) has been used as culture media to support the growth and activity of indigenous iron-oxidizing bacteria. Results showed that total organic carbon (TOC) concentrations of the culture media in excess of 235 mg/L were found to be inhibitory to bacterial growth. The oxidation rate increased as ferrous iron concentrations ranged from 10 to 40 g Fe2+/L. The percentage of ferrous iron (Fe2+) oxidized to ferric iron (Fe3+) increased as the hydraulic retention time (HRT) increased from 12 to 48 h. Successful and complete Fe2+ oxidation was recorded at a HRT of 48 h using 10 g Fe2+/L. Subsequently, ferric ion solution produced by A. ferrooxidans in sludge filtrate was used to solubilize heavy metals contained in wastewater sludge. The best solubilization was obtained with a mixture of primary and secondary sludge, demonstrating a removal efficiency of 63, 71, 49, and 80% for Cd, Cu, Cr, and Zn, respectively.  相似文献   
97.
The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones: Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting C stocks in Amazonia when such great pedological variability is not taken into account.  相似文献   
98.
In the summer of 2004, a video survey was carried out in the northern part of the central mud bank (Grande Vasière) of the Bay of Biscay to study the small scale relationship between the dominant crustacean megafauna Nephrops norvegicus, Munida rugosa and Goneplax rhomboides and juvenile hake (Merluccius merluccius). Using a towed body, high-resolution videos were recorded in six sampling sites. Statistical modelling using generalised additive models (GAM) revealed variations in activity patterns for two species. More N. norvegicus were observed outside their burrows at dawn and somewhat at dusk (no observations during night) while G. rhomboides was less observed in the morning. In addition, reduced spatial overlap between G. rhomboides and N. norvegicus suggested reduced competition for food but also space as both are burrowing species. The observed temporal and spatial activity patterns may contribute to regulating assemblage structure as competing species may be actively foraging at different times and locations thus reducing direct competition.  相似文献   
99.
Cassan D  Mercier B  Castex F  Rambaud A 《Chemosphere》2006,62(9):1507-1513
The aim of our study was to determine the impact of medium-pressure UV lamps radiation on water quality in a chlorinated indoor swimming pool. An indoor swimming pool was equipped with two medium-pressure UV lamps. We collected eight samples of water daily over a four-weeks period and measured total and free chlorine, pH, water temperature, bacteriological parameters, total organic carbon and trihalomethanes. During the first week, which served as control, medium-pressure UV lamps were turned off. During the next three weeks, medium-pressure UV lamps were kept on 24 h per day. The third week, we reduced the level of the injected chlorine into water, and the last week we also reduced the water renewal volume by 27%. Our results showed that bacteriological parameters remained within allowable french limits. When medium-pressure UV lamps were kept on, total, free and active chlorine levels were significantly increased (P<0.001), whereas combined chlorine level were significantly decreased (P<0.001 and P<0.05, respectively). The levels of chloroform and bromodichloromethane were significantly increased when medium-pressure UV lamps were kept on (P<0.001), whereas chlorodibromomethane and bromoform levels significantly decreased (P<0.05 and P<0.001, respectively). The additional formation of chloroform and bromodichloromethane may be explained by the increase in active chlorine and by radicalizing mechanisms initiated by UV radiation.  相似文献   
100.
Bottom sediments reflect in general the relative contamination of a sea area. Therefore, a great deal of monitoring work has been dedicated to the analysis of bottom sediments. Izmir Bay is a very important pollution centre in Turkish Aegean coast region due to a densely populated community, industrial complex and maritime transportation, and there are many streams flowing into the bay that pass through a number of industrial and agricultural areas. It had received the majority of domestic and industrial wastewaters until the wastewater treatment plant was constructed. It is well known that sediments play an important role as reservoirs of a fraction of the pollution in aquatic systems. Therefore, sediment samples were collected monthly from three stations which are located in the inner part of the bay during the period January to December 2003. Temporal variations and seasonal changes on their 210Po and 210Pb contents were examined, and the activity concentrations of 210Po and 210Pb were found to vary from 43±6 to 132±12 and 27±5 to 91±9 Bq kg???1 dry wt, respectively. The highest values of those natural radionuclides were measured at Kar??yaka Station because of the current systems of the bay. Seasonally, the 210Pb levels were found to increase during the winter time for all the stations.  相似文献   
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