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1.
Uğur A  Ozden B  Filizok I 《Chemosphere》2011,83(8):1102-1107
In this study, the activity concentrations of 210Po and 210Pb were determined in mussel samples (Mytilus galloprovincialis) collected from the Turkish coast of the Aegean Sea. The samples were collected seasonally for a period of two years (2004-2006) at six coastal stations (Çanakkale, Dikili, Foça, Çe?me, Didim, Bodrum). Mussels were separated into several groups according to their size (1-4, 4-6, >6 cm). The results showed that 210Po concentrations in mussels varied between 53 ± 4 and 1960 ± 60 Bq kg−1 dw. The highest activity 210Po concentrations were determined in winter samples of mussels with a shell length of 4-6 cm from Didim. In general, it was observed that the 210Pb concentration levels in mussels were lower than 210Po concentrations. The 210Po/210Pb activity concentration ratios exceeded unity for all mussel samples and averaged 26.0. The inter-site differences seen in 210Po concentrations can be due to both the natural background levels of sites and industrial activities.  相似文献   

2.
Natural steroidal estrogens, such as 17 β-estradiol (E2), as well as antimicrobials such as doxycycline and norfloxacin, are excreted by humans and hence detected in sewage sludge and biosolid. The disposal of human waste products on agricultural land results in estrogens and antibiotics being detected as mixtures in soils. The objective of this study was to examine microbial respiration and E2 mineralization in sewage sludge, biosolid, and soil in the presence and the absence of doxycycline and norfloxacin. The antimicrobials were applied to the media either alone or in combination at total rates of 4 and 40 mg kg?1, with the 4 mg kg?1 rate being an environmentally relevant concentration. The calculated time that half of the applied E2 was mineralized ranged from 294 to 418 days in sewage sludge, from 721 to 869 days in soil, and from 2,258 to 14,146 days in biosolid. E2 mineralization followed first-order and the presence of antimicrobials had no significant effect on mineralization half-lives, except for some antimicrobial applications to the human waste products. At 189 day, total E2 mineralization was significantly greater in sewage sludge (38 ±0.7%) > soil (23 ±0.7%) > biosolid (3 ±0.7%), while total respiration was significantly greater in biosolid (1,258 mg CO2) > sewage sludge (253 mg CO2) ≥ soil (131 mg CO2). Strong sorption of E2 to the organic fraction in biosolid may have resulted in reduced E2 mineralization despite the high microbial activity in this media. Total E2 mineralization at 189 day was not significantly influenced by the presence of doxycycline and/or norfloxacin in the media. Antimicrobial additions also did not significantly influence total respiration in media, except that total CO2 respiration at 189 day was significantly greater for biosolid with 40 mg kg?1 doxycycline added, relative to biosolid without antimicrobials. We conclude that it is unlikely for doxycycline and norfloxacin, or their mixtures, to have a significant effect on E2 mineralization in human waste products and soil. However, the potential for E2 to be persistent in biosolids, with and without the presence of antimicrobials, is posing a challenge for biosolid disposal to agricultural lands.  相似文献   

3.
Dissolved organic carbon (DOC), surface active substances (SAS) and copper complexing capacity (CuCC) were studied in bulk precipitations collected periodically from 2003 to 2007 in the continental city of Croatia (Zagreb: n = 27) and in the city at the Adriatic coast (?ibenik: n = 38). DOC concentrations (Zagreb: 0.67–4.03 mgC/L with average concentration of 1.93 ± 0.76 mgC/L; ?ibenik: 0.44–4.13 mgC/L with average concentration of 1.83 ± 0.83 mgC/L) are similar to those measured in other samples of continental rainwater in the northern hemisphere. The concentrations of SAS in samples from Zagreb ranged from 0.055 to 0.45 eq. Triton-X-100 mg/L with average concentration of (0.14 ± 0.06) eq. Triton-X-100 mg/L. SAS fractions were of a similar range in ?ibenik (0.02–0.60 eq. Triton-X-100 mg/L) with an average concentration of 0.11 ± 0.06 eq. Triton-X-100 mg/L. However, the lowest values of SAS (between 0.02 and 0.04 eq. Triton-X-100 mg/L) were observed only in ?ibenik (27%). We have estimated that the higher pH values were responsible for lower surface activity of organic matter in bulk samples from ?ibenik. DOC may form complexes that control the transport and solubility of heavy metals in natural water. CuCC measured in ?ibenik in the range 0.066–1.4 μM Cu2+ was in general higher, compared to the one in Zagreb (0.010–0.586 μM Cu2+) which is the result of biogenically driven organic contribution to the precipitation, especially in the warmer period of the year.  相似文献   

4.
The study deals with the identification and the determination of the main monoterpenes (α- and β-pinene) released by the pines in the Landes Forest in France. The measurements were taken after preconcentration using TENAX-GC and thermal desorption. The diurnal variation of atmospheric concentration of α- and β-pinene is established; it is less than 0.5 ppbV in the daytime and varies from 2 to 4 ppbV in the night-time. These variations are explained by the fact that the photochemical reactions and the turbulence phenomena to which the terpenes are exposed change quite radically from day to night. The terpene concentration, higher at 5 m than at 25 m, would seem to confirm the existence of a terpene source at ground level.  相似文献   

5.
Soil avoidance by earthworms has been generally considered a relevant and sensitive endpoint for assessing soil contamination by xenobiotics. However, when pesticide ecotoxicological assessment is concerned, the sensitivity of the recently standardized avoidance assay has been questioned. We hypothesized that this controversy may be due to the specific pesticide mode of action of the chemicals used rather than reveal inconsistencies in the test feasibility, i.e. provided that no pesticides interfering with neuronal pathways are tested, this bioassay should keep expected high levels of sensitivity. In this study, the avoidance behaviour of the earthworm Eisenia andrei under exposure to the carbamate insecticide methomyl [S-methyl N-(methylcarbamoyloxy)thioacetimidate] was linked to the corresponding acetylcholinesterase (AChE) inhibition. Significant AChE inhibition occurred at lower concentrations (from 0.86 mg Kg?1 onwards) than significant avoidance of spiked soil (from 5.62 mg Kg?1 onwards). This indicates that assessments regarding pesticides that have neurotoxic activity may be biased if behavioral endpoints are selected. Despite theoretical hypothesis that have been raised, this should be the first study providing preliminary experimental evidence on such a link between avoidance behavior and neuronal impairment levels in earthworms. Further studies are ongoing that should refine conclusions of this study.  相似文献   

6.
In April 1998, a holding lagoon containing pyrite ore processing waste rich in arsenic, failed and released 5-6 million m(3) of highly polluting sludge and acidic water. Over 2700 ha of the internationally important Do?ana National and Natural Parks were contaminated. The area of Natural Park to sustain the greatest impact was known as the Entremuros. This paper presents 0-5 cm soil monitoring data from the Entremuros, from sampling campaigns 6 and 18 months after the disaster; as well as macrophyte root, rhizome and stem data from samples taken 18 months after the spill. Results show a clear, decreasing, north-south arsenic soil pollution trend, both 6 and 18 months after the spill, and suggest a small reduction in total soil arsenic levels occurred over time; although a significant increase in extractable arsenic is also noted. The two macrophytes (Typha dominguensis and Scirpus maritimus) studied herein are not accumulating arsenic in stem parts, however, accumulation of arsenic on iron plaque on the roots of these plants may be occurring. Further work is recommended in order to determine the ecotoxicological significance of this process in relation to the avian food-chains of Do?ana, and elsewhere.  相似文献   

7.
Ozone data at the Jungfraujoch Observatory (3580 m asl) in the Swiss Alps have been recorded continuously since 1986 in the framework of the Swiss National Air Pollution Monitoring Network (NABEL), operated by the Swiss Federal Laboratories for Materials Testing and Research (EMPA). The long-term ozone record (1988–1996) was examined with regard to potential inhomogeneities using Zugspitze (2960 m asl), a neighbouring alpine site in Germany, as a reference site. The Alexandersson test (for shift) and the Easterling–Peterson test (for trend and shift) were applied to a difference times series, calculated from monthly ozone means at Jungfraujoch and Zugspitze. The Alexandersson test revealed a significant shift discontinuity in November 1989 and the Easterling–Peterson test a trend discontinuity in September 1991. It is assumed that the shift discontinuity may be related to an instrument change, but there is not firm evidence due to lack of detailed information from the instrumental history in the earlier years of the ozone record at Jungfraujoch. Monthly ozone means at Davos (1640 m asl) in eastern Switzerland indicate that part of the trend discontinuity in September 1991 may be of natural origin. Adjustment of the monthly ozone means at Jungfraujoch for the observed shift discontinuity removed the inhomogeneity in November 1989, and reduced the trend discontinuity by a factor of 4.8. A trend analysis on both adjusted (homogenised) and unadjusted monthly ozone means (1988–1996) at Jungfraujoch showed no statistically significant linear trend. The boundaries encompassing the true linear trend are indicated by two linear regression calculations on both adjusted and unadjusted data. Trends in the cold season are positive albeit not significant. The only statistically significant trends are found in October, December, and February for the adjusted data.  相似文献   

8.
Extremely high total cadmium concentrations (average about 500 mg/kg) together with very small (average of 1.1 microg/l) dissolved available cadmium have been found in the more acidic deeper layers of the bottom sediments of the Brazilian Amazonian Guajará Estuary. The paper shows that climatic changes and the periodic input of the Atlantic waters into the Estuary appear to have no direct influence on annual average total cadmium concentration, but they affect accumulation, distribution and remobilization of cadmium in different ways during the rainy season (February/March) and the dry season (November/December). Even if only a very small part of the total Cd is available, the concentrations of dissolved Cd in the Estuary are still high enough to cause environmental concern, if compared with concentrations in natural freshwater ecosystems.  相似文献   

9.
This article gives an overview of the studies on the environment surrounding the Abisko Scientific Research Station in Swedish Lapland. The long-term monitoring of the Station on processes related to the climate, and to the physical, biotic, and chemical environmental conditions is particularly addressed. Some variables are recorded since more than 100 years. The obtained data in combination with results from short-term studies and manipulation experiments are important to understand past and future conditions of the ecosystems. This has practical applications for the planning of tourism, transports, reindeer herding, and for societal purposes.  相似文献   

10.
In this analysis, we characterize urban and rural ozone (O3) trends across the US for the periods 1980–2008 (29 years) and 1994–2008 (15 years) using three exposure metrics, which summarize daily O3 concentrations to reflect different ways O3 may affect human health and vegetation. We observe that a statistically significant trend at a specific monitoring site, using one exposure metric, does not necessarily result in a similar trend using the other two metrics. The two most common trends among the monitoring sites are either a continuation of negative trending over the 29-year period or a shift from negative to no trend status, indicating a leveling off of the trending. Very few sites exhibit statistically significant increases in the exposure indices. In characterizing the statistically significant changes in the distribution of hourly average O3, we observe subtle statistically significant changes in the lower part of the distribution (i.e., below 50 ppb) that are not necessarily captured by the trending patterns associated with the three exposure metrics. Using multisite data from 12 metropolitan cities, we find that as the frequency of higher hourly average concentrations is reduced, the lower hourly average concentrations also move upward toward the mid-level values. The change in the number of the hourly average concentrations in the lower range is consistent with decreased NO scavenging. We recommend assessing possible subtle shifts in O3 concentrations by characterizing changes in the distribution of hourly average concentrations by month. Identifying statistically significant monthly changes in the mid- and low-level hourly average concentrations may provide important information for assessing changes in physical processes associated with global climate change, long-range transport, and the efficacy of models used for emission and risk reductions. Our results indicate that it is important to investigate the change in the trending pattern with time (e.g., moving 15-year trending) in order to assess how year-to-year variability may influence the trend calculation.  相似文献   

11.
The total (wet and dry) deposition of trace and major elements from the atmosphere was measured throughout 1 year at twelve sampling stations in the ‘Campo de Gibraltar’, an industrial zone where there are important residential areas. The data included in this paper have contributed to a better knowledge of the regional deposition of Al, Cr, Fe, Mn, Ni, Pb, V, Zn, Ca, Mg, K, Na, Cl, NH4+, NO3and SO42− in both soluble and insoluble form.  相似文献   

12.
Acute static tests were performed to assess Zn toxicity on adults of Cnesterodon decemmaculatus (not sexed), a neotropical fish of wide distribution in the Río de la Plata basin. Tests were carried out with ZnCl2 dissolved in natural waters from the Lower Paraná River, the Río de la Plata Estuary, reconstituted waters of similar composition, tap and distilled waters. Median lethal concentration at 24 h was positively correlated to conductivity and the concentrations of Ca2+, Mg2+, and HCO3- (r=0.99, 0.96, 0.97, 0.99, p<0.05, respectively), being higher at the Río de la Plata Estuary (61.2 mg l(-1)) than at the Lower Paraná River (35.3 mg l(-1)). Contaminant load in the natural waters tested was similar at both sites, being Zn concentration 40 and 44 microg l(-1), respectively. An assay with reconstituted water of similar alkalinity to the estuary showed a simultaneous decrease in HCO3- and dissolved Zn, while the Zn speciation, predicted with a computer program, suggested that Zn2+ precipitated as ZnCO3. The effect of Ca2+ on Zn toxicity is also discussed. Zn toxicity was higher in the Río de la Plata Estuary water than in synthetic water of similar ionic composition (24-h LC50 = 93.2 mg l(-1)), suggesting the synergistic effect of other toxic pollutants such as metals, present in the former which were absent in the later.  相似文献   

13.
Aerosol samples were collected from Northwest China desert region (Minqin), coastal suburb (Qingdao) and interior of the Yellow Sea (Qianliyan) in spring and summer of 1995 and 1996. Samples were analysed for major components, carbon and sulphur. The results show that concentrations of aerosols change considerably in time and space. The crustal materials carried by cold front system increase notably the aerosol concentration (mass/unit vol.) over the Yellow Sea but reduce the percentage contribution of pollutants and sea-salt. The sea-salt and regional aerosols become dominant fractions in coastal atmosphere in summer when the dust storms are expired in source region and the Southeast monsoon starts in the Pacific Ocean.  相似文献   

14.
Increasing eutrophication and algal bloom events in the Yangtze River Three Gorges Reservoir, China, are widely discussed with regard to changed hydrodynamics and nutrient transport and distribution processes. Insights into water exchange and interaction processes between water masses related to large-scale water level fluctuations in the reservoir are crucial to understand water quality and eutrophication dynamics. Therefore, confluence zones of tributaries with the Yangtze River main stream are dedicated key interfaces. In this study, water quality data were recorded in situ and on-line in varying depths with the MINIBAT towed underwater multi-sensor system in the confluence zone of the Daning River and the Yangtze River close to Wushan City during 1 week in August 2011. Geostatistical evaluation of the water quality data was performed, and results were compared to phosphorus contents of selective water samples. The strongly rising water level throughout the measurement period caused Yangtze River water masses to flow upstream into the tributary and supply their higher nutrient and particulate loads into the tributary water body. Rapid algal growth and sedimentation occurred immediately when hydrodynamic conditions in the confluence zone became more serene again. Consequently, water from the Yangtze River main stream can play a key role in providing nutrients to the algal bloom stricken water bodies of its tributaries.  相似文献   

15.
Environmental Science and Pollution Research - Microplastics (MPs) pervade the environment and increasingly threaten both natural ecosystems and human health. In this study, we investigated MP...  相似文献   

16.
17.
The level of some OCPs in human and cow milk collected from Asendabo, Serbo and Jimma in South-West Ethiopia were analyzed using GC–ECD. Results of the analysis indicated that all samples contained detectable quantities of p,p′-DDT and its metabolites, p,p-DDE and p,p-DDD, but none of the other OCPs analyzed. Mean levels of total DDT in the human and cow milk samples in the three areas were 12.68 and 0.389 μg g?1 respectively. The distributions of p,p-DDT, p,p-DDE and p,p-DDD in the human milk samples from the three locations followed the same trend in which the proportion of p,p-DDT was the highest in all the three cases, comprising 55–71% of total DDT, followed by p,p-DDE, 26–39%, and the least, p,p-DDD of 2–5%. The mean ratio of DDT/DDE concentration for the three areas was calculated to be 2.01. This value was much higher than the values reported from other countries in earlier studies and indicates the existence of a higher quantity of DDT from a fresh input in the three study areas. The mean estimated daily intake of DDT by infants from mother’s milk in the three locations was found to be 62.17 μg kg?1 body weight, which is about three times higher than the acceptable daily intake set by WHO/FAO for total DDT, 20 μg kg?1 of body weight. This alarmingly high daily intake value is a cause for concern, since children are highly susceptible to effects from such environmental contaminants. The study has revealed that people in the study areas are facing exposure to DDT from recent use. The observed contamination of mother’s milk and the possible transfer of the contaminant from mother to child is an obvious risk associated with breast-feeding in the study areas and possibly in other parts of the country too.  相似文献   

18.
In the middle of the last century in the case of many river basins, it became obvious that the targets of the Helsinki-Commission (HELCOM) concerning a 50% reduction of nitrogen and phosphorus inputs to the Baltic Sea had not been reached. Such conclusions could be derived from the observed loads. But the measurements regarding the analysis were not sufficient to determine what the reasons for this report were, what has to be done to fulfil this agreement and to evaluate the time at which the targets can be reached. This contribution presents the current state of Polish surface water quality as well as results of modelling nutrient and heavy metal emissions into the two biggest Polish river basins: Vistula and Odra, which both cover approximately 90% of Poland's territory.  相似文献   

19.
Edible mushrooms (Albatrellus ovinus, Boletus edulis, Clitocybe odora, Gomphidius glutinosus, Leccinum scabrum, Leccinum versipelle, Lycoperdon perlatum, Suillus bovinus, Suillus luteus, and Xerocomus subtomentosus) collected from unpolluted areas of the city of Umeå and its outskirts in the northern part of Sweden were examined for contents of toxic metallic elements (Cd, Pb, and Ag) and essential macro- and microelements (K, Na, Ca, Mg, Cu, Fe, Mn, and Zn) using a validated method and a final measurement by flame atomic absorption spectroscopy (F-AAS). The median values of the toxic metallic element concentrations (in mg kg?1 dry biomass, db) ranged from: 0.12–3.9, 0.46–5.1, and 0.91–6.2 for Ag, Cd and Pb, respectively. For the essential metallic elements, the median values of concentrations ranged from: 24000–58000, 15–2000, 59–610, 520–1900, 2.0–97, 16–150, 15–120, and 4.3–26 mg kg?1 db for K, Na, Ca, Mg, Cu, Zn, Fe, and Mn, respectively. The baseline concentrations of the metallic elements determined in mushrooms were mainly affected by the fungal species. The assessed probable maximal dietary intake of Cd (0.002 mg kg?1 body mass) solely from a mushroom meal was only slightly below a revised value of the tolerable weekly intake for this element, while for Pb (0.003 mg kg?1 body mass) it was tenfold below the provisionally tolerable weekly intake.  相似文献   

20.
Emission reductions were mandated in the Clean Air Act Amendments of 1990 with the expectation that they would result in major reductions in the concentrations of atmospherically transported pollutants. This paper investigates the form and magnitude of trends from 1989 to 1995 in atmospheric concentrations of sulfur dioxide, sulfate, and nitrogen at 34 rural sites in the eastern US. Across all sites, there is strong evidence of statistically significant declining trends in sulfur dioxide (median change of -35%) and sulfate concentrations (median change of -26%). In general, trends in nitrogen concentrations were not as pronounced (median change of -8%) as trends in the sulfur compounds. A regional estimate of trend for a cluster of sites in the Ohio River valley showed close correspondence between declining sulfur dioxide concentrations (-35%) and changes in sulfur dioxide emissions (-32%) in this region.  相似文献   

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