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91.
Distribution and relationships of As,Cd, Pb and Hg in freshwater fish from five French fishing areas
Laurent Noël Rachida Chekri Sandrine Millour Mathilde Merlo Jean-Charles Leblanc Thierry Guérin 《Chemosphere》2013,90(6):1900-1910
The concentrations of arsenic, cadmium, mercury and lead in 149 muscle samples of eight freshwater fish species (European eel, bream, common carp, European catfish, roach, perch, pike and pikeperch) from five different French fishing areas from contaminated and control sites were measured by inductively coupled plasma mass spectrometry after microwave digestion under pressure. No significant correlation was found between the condition factor (CF), based on the length–mass relationship, and As, Cd and Pb levels in all the samples analysed, but a positive correlation was detected between CF and Hg levels (P < 0.0001, R = 0.49). Positive correlations with body length were only found for Hg in roach (P < 0.05, R = 0.32) and Pb in bream (P < 0.05, R = 0.48) and correlations with both body weight and length were also found for Hg in pike (P < 0.05, R = 0.90 and 0.86) and Cd in European eel (P < 0.01, R = ?0.35 and ?0.37). The average content and the standard deviation in fish muscle samples was 0.007 ± 0.012, 0.102 ± 0.077, 0.142 ± 0.097 and 0.035 ± 0.053 mg kg?1 of wet mass for Cd, As, Hg and Pb, respectively. Significant differences were established between groups of predatory fish and non-predatory fish for Hg and Pb, and between control and contaminated sites in the whole selection and also within feeding guilds, i.e. the values of Hg in the benthophagic fish were significantly different between these sites. Finally, these results were also compared for each species with previous French and European studies. 相似文献
92.
Héctor G. Riveros Javier Tejeda Luis Ortiz Adriana Julián-Sánchez Héctor Riveros-Rosas 《Journal of the Air & Waste Management Association (1995)》2013,63(12):973-984
Abstract In Mexico City, the use and composition of fuels determine that carbon monoxide (CO) comes mostly from mobile sources, and sulfur dioxide (SO2) from fixed and mobile sources. By simultaneously measuring hydrocarbons (HC), CO, and SO2 in the atmosphere of Mexico City, the relative amounts coming from different sources can be estimated. Assuming that some HC are emitted proportionally to CO emissions, we can establish that [HC]1= m1? [CO], where the proportionality constant ml corresponds to the ratio of emissions factor for HC and CO in mobile sources. Similarly for fuels containing sulfur, it can be assumed that [HC]2 = m2 ? [SO2]. In this way, the total HC are [HC]total=[HC]0+ ml ? [CO]+ m2 ? [SO2], where [HC]0 corresponds mainly to other sources like solvent evaporation, gas consumption, and natural emissions. In this way, it can be estimated that in Mexico City 75% of average HC comes from mobile sources, 5% from sulfur-related sources, and 19% from natural sources and solvent evaporation. Compared with the HC/CO ratio measured in the exhaust pipe of vehicles, we estimated that 70% of HC emitted from mobile sources are evaporative losses, and only 30% come through the exhaust system. 相似文献
93.
Andrew C. VanderZaag Hambaliou Baldé Jemaneh Habtewold Etienne L. Le Riche Stephen Burtt Kari Dunfield 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1096-1106
Liquid manure storages are a significant source of methane (CH4) emissions. Farmers commonly agitate (stir) liquid manure prior to field application to homogenize nutrients and solids. During agitation, manure undergoes mechanical stress and is exposed to the air, disrupting anaerobic conditions. This on-farm study aimed to better understand the effects of agitation on CH4 emissions, and explore the potential for intentional agitation (three times) to disrupt the exponential increase of CH4 emissions in spring and summer. Results showed that agitation substantially increased manure temperature in the study year compared to the previous year, particularly at upper- and mid-depths of the stored manure. The temporal pattern of CH4 emissions was altered by reduced emissions over the subsequent week, followed by an increase during the second week. Microbial analysis indicated that the activity of archaea and methanogens increased after each agitation event, but there was little change in the populations of methanogens, archaea, and bacteria. Overall, CH4 emissions were higher than any of the previous three years, likely due to warmer manure temperatures that were higher than the previous years (despite similar air temperatures). Therefore, intermittent manure agitation with the frequency, duration, and intensity used in this study is not recommended as a CH4 emission mitigation practice.Implications: The potential to mitigate methane emissions from liquid manure storages by strategically timed agitation was evaluated in a detailed farm-scale study. Agitation was conducted with readily-available farm equipment, and targeted at the early summer to disrupt methanogenic communities when CH4 emissions increase exponentially. Methane emissions were reduced for about one week after agitation. However, agitation led to increased manure temperature, and was associated with increased activity of methanogens. Overall, agitation was associated with similar or higher methane emissions. Therefore, agitation is not recommended as a mitigation strategy. 相似文献
94.
This study examined the tissues distribution of selected serotonin reuptake inhibitors (SSRIs) in brook trout exposed for 3 months to continuous flow-through primary-treated effluent before and after ozone treatment. A reliable analytical method was developed for the quantification of trace amounts of antidepressants in small tissue homogenate extracts. Levels of six antidepressants and four of their N-desmethyl metabolites were determined using liquid chromatography-tandem mass spectrometry. Significant amounts of the SSRIs were found in fish tissue-in decreasing order: liver>brain>muscle. Sertraline and its metabolite desmethylsertraline were the predominant substances observed in most tissues (0.04-10.3 ng g(-1)). However, less SSRIs (0.08-1.17 ng g(-1)) were bioaccumulated in the ozonated effluent. The early molecular effects of these SSRIs on the Na/K-dependent ATPase pump activity in brain synaptosomes where also investigated in vitro and in fish exposed to the municipal effluents. With respect to their potential biological effects, in vitro exposure to selected SSRIs induced a reduction of the brain Na/K-ATPase activity in synaptosomes in a dose-dependent manner. Results showed that Na/K-ATPase activity was readily inhibited by exposure to municipal effluent before and, to a lesser extent, after ozone treatment. Moreover, the Na/K-ATPase activity was significantly and negatively correlated with brain tissue concentrations of fluoxetine (r=-0.57; p<0.03), desmethylsertraline (r=-0.84; p<0.001), and sertraline (r=-0.82; p<0.001). The present study reveals that SSRIs are readily available in fish, biologically active and corroborates previous findings on the serotonergic properties of municipal effluents to aquatic organisms. 相似文献
95.
In this field study, two approaches to assess contaminant mass discharge were compared: the sampling of multilevel wells (MLS) and the integral groundwater investigation (or integral pumping test, IPT) that makes use of the concentration-time series obtained from pumping wells. The MLS approached used concentrations, hydraulic conductivity and gradient rather than direct chemical flux measurements, while the IPT made use of a simplified analytical inversion. The two approaches were applied at a control plane located approximately 40m downgradient of a gasoline source at Canadian Forces Base Borden, Ontario, Canada. The methods yielded similar estimates of the mass discharging across the control plane. The sources of uncertainties in the mass discharge in each approach were evaluated, including the uncertainties inherent in the underlying assumptions and procedures. The maximum uncertainty of the MLS method was about 67%, and about 28% for the IPT method in this specific field situation. For the MLS method, the largest relative uncertainty (62%) was attributed to the limited sampling density (0.63 points/m(2)), through a novel comparison with a denser sampling grid nearby. A five-fold increase of the sampling grid density would have been required to reduce the overall relative uncertainty for the MLS method to about the same level as that for the IPT method. Uncertainty in the complete coverage of the control plane provided the largest relative uncertainty (37%) in the IPT method. While MLS or IPT methods to assess contaminant mass discharge are attractive assessment tools, the large relative uncertainty in either method found for this reasonable well monitored and simple aquifer suggests that results in more complex plumes in more heterogeneous aquifers should be viewed with caution. 相似文献
96.
There is the need to integrate existing toxicity data in a coherent framework for extending their domain of applicability as well as their extrapolation potential. This integration would also reduce time and cost-consuming aspects of these tests and reduce animal usage. In this work, based on data extracted from literature, we have assessed the advantages that a dynamic biology-toxicant fate coupled model for Daphnia magna could provide when assessing toxicity data, in particular, the possibility to obtain from short-term (acute) toxicity test long-term (chronic) toxicity values taking into account the inherent variability of D. magna populations and the multiple sources of data. The results show that this approach overcomes some of the limitations of existing toxicity tests and that the prediction errors are considerably reduced when compared with the factor from 2 to 5 obtained using acute-to-chronic ratios. 相似文献
97.
Development of a combined isotopic and mass-balance approach to determine dissolved organic carbon sources in eutrophic reservoirs 总被引:1,自引:0,他引:1
Pierson-Wickmann AC Gruau G Jardé E Gaury N Brient L Lengronne M Crocq A Helle D Lambert T 《Chemosphere》2011,83(3):356-366
A combined mass-balance and stable isotope approach was set up to identify and quantify dissolved organic carbon (DOC) sources in a DOC-rich (9 mg L−1) eutrophic reservoir located in Western France and used for drinking water supply (so-called Rophemel reservoir). The mass-balance approach consisted in measuring the flux of allochthonous DOC on a daily basis, and in comparing it with the effective (measured) DOC concentration of the reservoir. The isotopic approach consisted, for its part, in measuring the carbon isotope ratios (δ13C values) of both allochthonous and autochthonous DOC sources, and comparing these values with the δ13C values of the reservoir DOC. Results from both approaches were consistent pointing out for a DOC of 100% allochthonous origin. In particular, the δ13C values of the DOC recovered in the reservoir (−28.5 ± 0.2‰; n = 22) during the algal bloom season (May-September) showed no trace of an autochthonous contribution (δ13C in algae = −30.1 ± 0.3‰; n = 2) being indistinguishable from the δ13C values of allochthonous DOC from inflowing rivers (−28.6 ± 0.1‰; n = 8). These results demonstrate that eutrophication is not responsible for the high DOC concentrations observed in the Rophemel reservoir and that limiting eutrophication of this reservoir will not reduce the potential formation of disinfection by-products during water treatment. The methodology developed in this study based on a complementary isotopic and mass-balance approach provides a powerful tool, suitable to identify and quantify DOC sources in eutrophic, DOC-contaminated reservoirs. 相似文献
98.
Ruiz I Morales A Oliva J Barba A 《Journal of environmental science and health. Part. B》2011,46(6):530-534
An analytical procedure has been developed for the determination of natural pyrethrins (pyrethrin I, pyrethrin II, jasmolin I, jasmolin II, cinerin I and cinerin II) in lemon and apricot. The QuEChERS method, which stands for quick, easy, cheap, effective, rugged and safe was used for extraction. Analysis of the extract was performed by liquid-chromatography-electrospray ionisation-tandem mass spectrometry. The ions prominent in the ESI spectra were [M+H]+ for the six compounds. A Zorbax SB-C18 column was used with a programmed gradient mobile phase consisting of (A) water containing 0.1% formic acid and 5 mM ammonium formate and (B) ACN. The method was linear within the investigated concentration range, displaying a calibration curve correlation factor of 0.99. The coefficients of variation obtained (RSD) were below 20% and the recoveries were in the 70-110% range. 相似文献
99.
Morales A Ruiz I Oliva J Barba A 《Journal of environmental science and health. Part. B》2011,46(6):525-529
A method for the detection and quantification of 16 pesticides: flufenoxuron, fenoxycarb, dimethomorph, acetamiprid, imidacloprid, lufenuron, thiacloprid, thiabendazole, thiophanate-methyl, spinosad, fenbutatin oxide, methoxyfenozide, oxamyl, clothianidin, thiamethoxam and carbendazim has been developed based on high-performance liquid chromatography-mass spectrometry. Pesticide residues were extracted from the samples according to the QuEChERS method which stands for quick, essay, cheap, effective, rugged and safe. Homogenised analytical portions (10 g ± 0.1) of samples of peppers were spiked at two levels (10 and 100 μg kg?1) with a small volume of an appropriate standard mixture solution containing each pesticide. Analyses were performed using electrospray ionization (ESI) and a MSD trap system. Chromatography separation was achieved using a ZORBAX SB-C18 3.5 μm particle size analytical column, 2.1 × 50 mm from Agilent, with gradient elution at a flow-rate of 0.4 mL/min with mobile phases: waters-0.1 % HCOOH-5 mM HCOONH? and MeOH-5 mM HCOONH?. The method has been validated based on the SANCO European Guidelines. Under the optimized conditions the recoveries (n = 7) were in the range 70-110 % with satisfactory precision (CV ≤ 20 %). A linear dynamic range was obtained over a range of concentrations from 10 to 100 μg kg?1 for each of the analytes, with correlation coefficients >0.997. 相似文献
100.
Stefanie Grund Eric Higley René Schönenberger Marc J-F. Suter John P. Giesy Markus Hecker Henner Hollert 《Environmental science and pollution research international》2011,18(3):446-460