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Результаты 3221-3230 из 4,033
Assessment of heavy metal contamination levels and toxicity in sediments and fishes from the Mediterranean Sea (southern coast of Sfax, Tunisia)
2016
Zohra, Ben Salem | Habib, Ayadi
Contamination of heavy metals in sediment is regarded as a global crisis with a large share in industrializing cities like Sfax (Tunisia). Seven heavy metals such as Cadmium (Cd), Copper (Cu), Iron (Fe), Mercury (Hg), Nickel (Ni), Lead (Pb), and Zinc (Zn), and one metalloid such as Arsenic (As) in sediments and fish (D. annularis, L. aurata, and S. vulgaris) were investigated from the Southern coast of Sfax in Tunisia. The range of metals in sediments were 13.11–36; 4.42–7.92; 8.23–28.56; 50,564–11,956; 2.9–6.8; 9.13–30.51; 65.06–151.50, and 47–546 kg⁻¹ DW for As, Cd, Cu, Fe, Hg, Ni, Pb, and Zn. The level of studied metals in sediment samples exceeded the limits of the quality assessment guidelines (SQGs). The potential ecological risk index (PERI) proved that the investigated region could pose moderate risk for the aquatic biota. Metal bioaccumulation in the fish muscles varied significantly among species. Indeed, S. vulgaris and D. annularis accumulated higher amount of metal than L. aurata. The target hazard quotients (THQ) of individual heavy metals in fish, except for As and Hg, revealed safe levels for human consumption. Nevertheless, the total THQ indexes exceeded 1 suggesting the combined effects on muscles fish, which may constitute a risk to population’s health.
Показать больше [+] Меньше [-]Investigation of fluorine content in PM2.5 airborne particles of Istanbul, Turkey
2016
Ozbek, Nil | Baltaci, Hakki | Baysal, Asli
Fluorine determination in airborne samples is important due to its spread into the air from both natural and artificial sources. It can travel by wind over large distances before depositing on the Earth’s surface. Its concentration in various matrices are limited and controlled by the regulations for causing health risks associated with environmental exposures. In this work, fluorine was determined in PM2.5 airborne samples by high-resolution continuum source electrothermal atomic absorption spectrometry. For these purpose, the PM2.5 airborne particulates were collected on quartz filters using high-volume samplers (500 L/min) in Istanbul (Turkey) for 96 h during January to June in 2 years. Then, instrumental and experimental parameters were optimized for the analyte in airborne samples. The validity of the method for the analyte was tested using standard reference material, and certified values were found in the limits of 95 % confidence level. The fluorine concentrations and meteorological conditions were compared statistically.
Показать больше [+] Меньше [-]Simultaneous determination of estrogenic odorant alkylphenols, chlorophenols, and their derivatives in water using online headspace solid phase microextraction coupled with gas chromatography-mass spectrometry
2016
Yuan, Su-fen | Liu, Ze-hua | Lian, Hai-Xian | Yang, Chuangtao | Lin, Qing | Yin, Hua | Dang, Zhi
A simple online headspace solid-phase microextraction (HS-SPME) coupled with the gas chromatography-mass spectrometry (GC-MS) method was developed for simultaneous determination of trace amounts of nine estrogenic odorant alkylphenols and chlorophenols and their derivatives in water samples. The extraction conditions of HS-SPME were optimized including fiber selection, extraction temperature, extraction time, and salt concentration. Results showed that divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was the most appropriate one among the three selected commercial fibers, and the optimal extraction temperature, time, and salt concentration were 70 °C, 30 min, and 0.25 g/mL, respectively. The developed method was validated and showed good linearity (R ² > 0.989), low limit of detection (LOD, 0.002–0.5 μg/L), and excellent recoveries (76–126 %) with low relative standard deviation (RSD, 0.7–12.9 %). The developed method was finally applied to two surface water samples and some of these target compounds were detected. All these detected compounds were below their odor thresholds, except for 2,4,6-TCAS and 2,4,6-TBAS wherein their concentrations were near their odor thresholds. However, in the two surface water samples, these detected compounds contributed to a certain amount of estrogenicity, which seemed to suggest that more attention should be paid to the issue of estrogenicity rather than to the odor problem.
Показать больше [+] Меньше [-]Degradation of flubendiamide as affected by elevated CO2, temperature, and carbon mineralization rate in soil
2016
Mukherjee, Irani | Das, Shaon Kumar | Kumar, Aman
An experiment was conducted under three levels of atmospheric CO₂ [ambient (398 ± 10 μmol mol⁻¹), elevated (570 ± 10 μmol mol⁻¹) and open condition], three levels of temperature (4, 25, and 40 °C) to study the degradation pattern of flubendiamide in soil and also carbon mineralization in soil. Results of this study revealed that flubendiamide was found to persist longer under outdoor condition (T₁/₂, 177.0 and 181.1 days) than ambient (T₁/₂, 168.4 and 172.3 days) and elevated condition (T₁/₂, 159.3 and 155.3 days) at 1 and 10 μg g⁻¹ fortification level, respectively. Results also revealed that flubendiamide dissipated faster at 40 °C (T₁/₂, 189.4 days) than 25 °C (T₁/₂, 225.3 days). Slower dissipation was recorded at 4 °C (T₁/₂, 326.3 days). Thus, increased CO₂ levels and temperature following global warming might adversely affect flubendiamide degradation in soil. Laboratory study on microbial biomass carbon (MBC) and carbon mineralization (Cₘᵢₙ) in soil revealed that in des-iodo flubendiamide-treated soils, MBC significantly increased up to 45 days and then decreased. Flubendiamide-treated soil showed a non-significantly decreasing trend of soil MBC with time up to the 15th day of incubation and after 15 days significantly decreased up to 90 days of incubation. In des-iodo flubendiamide-treated soil, the evolution of CO₂ decreased up to 45 days, which was increased after 45 days up to 90 days. In flubendiamide-treated soil, CO₂ evolution decreased up to 30 days and after 45 days, it increased up to 90 days.
Показать больше [+] Меньше [-]Evaluation of the activity concentrations of 137 Cs and 40K in some Chanterelle mushrooms from Poland and China
2016
Falandysz, Jerzy | Zalewska, Tamara | Apanel, Anna | Drewnowska, Małgorzata | Kluza, Karolina
The activity concentrations of ¹³⁷Cs and ⁴⁰K in mushrooms of the genus Cantharellus (Cantharellus cibarius, Cantharellus tubaeformis, and Cantharellus minor) collected across Poland from 1997 to 2013 and in Yunnan province of China in 2013 were determined using gamma spectrometry with an HPGe detector, respectively. Activity concentrations of ¹³⁷Cs in C. cibarius from the places in Poland varied from 64 ± 3 to 1600 ± 47 Bq kg⁻¹ db in 1997–2004 and 4.2 ± 1.2 to 1400 ± 15 Bq kg⁻¹ db in 2006–2013. In the Chinese Cantharellus mushrooms, the activity level of ¹³⁷Cs was very low, i.e., at a range <1.2 to 1.2 ± 0.6 Bq kg⁻¹ dry biomass. The natural radionuclide ⁴⁰K was at similar activity level in C. cibarius collected across Poland and in China, and fluctuations in levels of ⁴⁰K over the years and locations in Poland were small. In C. cibarius from diverse sites in Poland, content of ¹³⁷Cs highly fluctuated in 1998–2013 but no clear downward trend was visible (Fig. 1). Published activity levels of ¹³⁷Cs in fruitbodies of Cantharellus such Cantharellus californicus, Cantharellus cascadensis, C. cibarius, Cantharellus cinnabarius, Cantharellus formosus, Cantharellus iuteocomus, Cantharellus lutescens, Cantharellus minor, Cantharellus pallens [current name C. cibarius], Cantharellus subalbidus, Cantharellus subpruinosus, and C. tubaeformis collected worldwide were compared. In the Polish cuisine, mushrooms of the genus Cantharellus are blanched before frying or pickling, and this kind of treatment, and additionally also pickling, both very efficiently remove alkali elements (and radioactivity from ¹³⁴/¹³⁷Cs) from flesh of the species.
Показать больше [+] Меньше [-]Polycyclic aromatic hydrocarbons (PAHs) at traffic and urban background sites of northern Greece: source apportionment of ambient PAH levels and PAH-induced lung cancer risk
2016
Manoli, Evangelia | Kouras, Athanasios | Karagkiozidou, Olga | Argyropoulos, Georgios | Voutsa, Dimitra | Samara, Constantini
Thirteen particle-phase PAHs, including nine >4-ring congeners [Benz[a]anthracene (BaAn), Chrysene (Chry), Benzo[b]fluoranthene (BbF), Benzo[k]fluoranthene (BkF), Benzo[e]pyrene (BeP), Benzo[a]pyrene (BaP), Dibenzo[a,h]anthracene (dBaAn), Benzo[g,h,i]perylene (BghiPe), Indeno(1,2,3-c,d)pyrene (IP)], listed by IARC (International Agency for Research on Cancer) as class 1, class 2A, and 2B carcinogens, plus four ≤4-ring congeners [Phenanthrene (Ph), Anthracene (An), Fluoranthene (Fl), Pyrene (Py)], were concurrently measured in inhalable and respirable particle fractions (PM₁₀ and PM₂.₅) at a heavy-traffic and an urban background site in Thessaloniki, northern Greece, during the warm and the cold period of the year. Carcinogenic and mutagenic potencies of the PAH-bearing particles were calculated, and the inhalation cancer risk (ICR) for local population was estimated. Finally, Chemical Mass Balance (CMB) modeling was employed for the source apportionment of ambient PAH levels and the estimated lung cancer risk. Resulted inhalation cancer risk during winter was found to be equivalent in the city center and the urban background area suggesting that residential wood burning may offset the benefits from minor traffic emissions.
Показать больше [+] Меньше [-]Heavy metal bioaccumulation by wild edible saprophytic and ectomycorrhizal mushrooms
2016
Širić, Ivan | Humar, Miha | Kasap, Ante | Kos, Ivica | Mioč, Boro | Pohleven, Franc
Heavy metals cause serious problems in the environment, and they can be accumulated in organisms, especially in the higher fungi. The concentration of Ni, Cr, Pb, Cd, and Hg in 10 species of edible mushrooms in Medvednica Nature Park, Croatia was therefore determined. In addition, the similarity between the studied species was determined by cluster analysis based on concentrations of the aforementioned metals in the fruiting bodies. The contents of nickel, chromium, lead, cadmium, and mercury in the fruiting bodies of mushrooms were obtained by X-ray fluorescence spectrometry. The highest concentrations of Ni (3.62 mg kg⁻¹), Cr (3.01 mg kg⁻¹), and Cd (2.67 mg kg⁻¹) were determined in Agaricus campestris. The highest concentration of Pb (1.67 mg kg⁻¹) was determined in Macrolepiota procera, and the highest concentration of Hg (2.39 mg kg⁻¹) was determined in Boletus edulis. The concentration of all heavy metals significantly differed (p < 0.001) between examined saprophytic and ectomycorrhizal mushrooms. Considering anatomical part of the fruiting body (cap-stipe), a considerably higher concentration of the analyzed elements was found in the cap for all mushroom species. According to calculated bioconcentration factors, all the examined species were found to be bioexclusors of Ni, Cr, and Pb and bioaccumulators of Cd and Hg. Cluster analysis performed on the basis of the accumulation of the studied metals revealed great phenotypic similarity of mushroom species belonging to the same genus and partial similarity of species of the same ecological affiliation.
Показать больше [+] Меньше [-]Soil ecotoxicology in Brazil is taking its course
2016
Niva, Cintia Carla | Niemeyer, Julia Carina | Júnior, Flávio Manoel Rodrigues Da Silva | Nunes, Maria Edna Tenório | De Sousa, Danilo Lourenço | Aragão, Clara Wandenkolck Silva | Sautter, Klaus Dieter | Espindola, Evaldo Gaeta | Sousa, José Paulo | Römbke, Jörg
Soil ecotoxicology has been motivated by the increasing global awareness on environmental issues. Northern Hemisphere has been the main driver of this science branch; however, the number and quality of contributions from the Southern Hemisphere are increasing quickly. In this case study, Brazil is taken as an example of how soil ecotoxicology has developed over the last 30 years. It starts with a brief historical overview depicting the main events on soil ecotoxicology in the country. Following, an overview on the Brazilian legislation related to soil ecotoxicology is given, covering regulations with prospective focus, mainly on the registration of pesticides. Regulations with retrospective focus in contaminated areas are also given. Then, an outline of the actors in soil ecotoxicology and examples of prospective ecotoxicological studies performed with soil organisms and plants are given by stressor groups: pesticides, pharmaceuticals, metals, and residues. Experiences from retrospective studies, mainly looking at the assessment of industrial sites, are also covered. Emphasis is given on methodological aspects, pointing to needed actions, mainly regarding the different biotic and abiotic conditions of a tropical country. Finally, the last session discusses how soil ecotoxicology could be improved in methodological adaptations as well as legal requirements.
Показать больше [+] Меньше [-]Managing the drinking water catchment areas: the French agricultural cooperatives feed back
2016
Charrière, Séverine | Aumond, Claire
The quality of raw water is problematic in France, largely polluted by nitrates and pesticides (Mueller and Helsel, Nutrients in the nation’s waters—too much of a good thing? Geological Survey (U.S.), 1996; European Environment Agency, European waters—assessment of status and pressures, 2012).This type of pollution, even though not always due to agriculture (example of the catchment of Ambleville, county 95, France where the nitrate pollution is mainly due to sewers (2012)), has been largely related to the agricultural practices (Sci Total Environ 407:6034–6043, 2009).Taking note of this observation, and instead of letting it paralyze their actions, the agricultural cooperatives decided with Agrosolutions to act directly on the field with their subscribers to change the agricultural practices impacting the water and the environment.This article shows how the French agricultural cooperatives transformed the awareness of the raw water quality problem into an opportunity for the development and implementation of more precise and responsible practices, to protect their environment. They measure in order to pilot, co-construct and build the best action plans possible according to the three pillars of environment, economy and agronomy.
Показать больше [+] Меньше [-]Use of RSM modeling for optimizing decolorization of simulated textile wastewater by Pseudomonas aeruginosa strain ZM130 capable of simultaneous removal of reactive dyes and hexavalent chromium
2016
Maqbool, Zahid | Ḥussain, Ṣābir | Aḥmad, Tanvīr | Nadeem, Habibullah | Imran, Muhammad | Khalid, Azeem | Abid, Mohamed | Martin-Laurent, Fabrice
Remediation of colored wastewater loaded with dyes and metal ions is a matter of interest nowadays. In this study, 220 bacteria isolated from textile wastewater were tested for their potential to decolorize each of the four reactive dyes (reactive red-120, reactive black-5, reactive yellow-2, and reactive orange-16) in the presence of a mixture of four different heavy metals (Cr, Zn, Pb, Cd) commonly found in textile effluents. Among the tested bacteria, the isolate ZM130 was found to be the most efficient in decolorizing reactive dyes in the presence of the mixture of heavy metals and was identified as Pseudomonas aeruginosa strain ZM130 by 16S rRNA gene analysis. The strain ZM130 was highly effective in simultaneously removing hexavalent chromium (25 mg L⁻¹) and the azo dyes (100 mg L⁻¹) from the simulated wastewater even in the presence of other three heavy metals (Zn, Pb, Cd). Simultaneous removal of chromium and azo dyes ranged as 76.6–98.7 % and 51.9–91.1 %, respectively, after 180 h incubation. On the basis of quadratic polynomial equation and response surfaces given by the response surface methodology (RSM), optimal salt content, pH, carbon co-substrate content, and level of multi-metal mixtures for decolorization of reactive red-120 in a simulated textile wastewater by the strain ZM130 were predicted to be 19.8, 7.8, and 6.33 g L⁻¹ and a multi-metal mixture (Cr 13.10 mg L⁻¹, Pb 26.21 mg L⁻¹, Cd 13.10 mg L⁻¹, Zn 26.21 mg L⁻¹), respectively. Moreover, the strain ZM130 also exhibited laccase and nicotinamide adenine dinucleotide (reduced)-dichlorophenolindophenol reductase (NADH-DCIP reductase) activity during the decolorization of reactive red-120. However, the laccase activity was found to be maximum in the presence of 300 mg L⁻¹ of the dye as compared to other concentrations. Hence, the isolation of this strain might serve as a potential bio-resource required for developing the strategies aiming at bioremediation of the wastewater contaminated with dyes and heavy metals.
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