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Mercury-induced genotoxicity in marine diatom (Chaetoceros tenuissimus) Полный текст
2016
Sarker, Subhodeep | Desai, Somashekhar R. | Verlecar, Xivanand N. | Saha Sarker, Munmun | Sarkar, A.
In this paper, we present an evaluation of genotoxic responses in marine diatom, Chaetoceros tenuissimus, isolated from Kandla Creek (lat 23.03° N, long 70.22° E), Gujarat, India, in terms of impairment of DNA integrity as a function of their exposure to elevated levels of mercury (Hg) under laboratory conditions. DNA integrity in C. tenuissimus was determined by partial alkaline unwinding assay. To our knowledge, this is the first such genotoxicity study to be conducted on marine diatom cultures towards understanding the relationship between Hg toxicity and DNA damage. Furthermore, we studied the impact of Hg on the growth of C. tenuissimus as a function of their exposure to enhanced levels of Hg in terms of decreasing chlorophyll a (chl a) concentrations. The data show the genotoxic effect of Hg on the growth of C. tenuissimus as well as DNA integrity to a great extent. Based on the results of our investigations, it is suggested that C. tenuissimus can be used as sentinel species for bio-monitoring of pollution due to genotoxic contaminants.
Показать больше [+] Меньше [-]PCB remediation in schools: a review Полный текст
2016
Brown, Kathleen W. | Minegishi, Taeko | Cummiskey, Cynthia Campisano | Fragala, Matt A. | Hartman, Ross | MacIntosh, D. L. (David L.)
Growing awareness of polychlorinated biphenyls (PCBs) in legacy caulk and other construction materials of schools has created a need for information on best practices to control human exposures and comply with applicable regulations. A concise review of approaches and techniques for management of building-related PCBs is the focus of this paper. Engineering and administrative controls that block pathways of PCB transport, dilute concentrations of PCBs in indoor air or other exposure media, or establish uses of building space that mitigate exposure can be effective initial responses to identification of PCBs in a building. Mitigation measures also provide time for school officials to plan a longer-term remediation strategy and to secure the necessary resources. These longer-term strategies typically involve removal of caulk or other primary sources of PCBs as well as nearby masonry or other materials contaminated with PCBs by the primary sources. The costs of managing PCB-containing building materials from assessment through ultimate disposal can be substantial. Optimizing the efficacy and cost-effectiveness of remediation programs requires aligning a thorough understanding of sources and exposure pathways with the most appropriate mitigation and abatement methods.
Показать больше [+] Меньше [-]Analysis of sulfonamides in soil, sediment, and sludge based on dynamic microwave-assisted micellar extraction Полный текст
2016
Wang, Hui | Ding, Jie | Ding, Lan | Ren, Nanqi
A green and high-throughput analytical method was described for the simultaneous determination of ten sulfonamides (SAs) from soil, sediment, and sludge in northeast China. None of potentially hazardous organic solvents was used in the whole sample preparation procedure, and the total preparation time of 15 samples was about 18 min. The limits of detection for the SAs were in the range of 0.42–0.68 ng g⁻¹. The intra-day and inter-day precisions, expressed by the relative standard deviation, were below 7 %. Under the optimum conditions, the recoveries of ten SAs were between 69.7 and 102.7 %. The proposed method was successfully applied to analyze the SAs residues in agricultural soils, river sediments, and sewage sludge. SAs were found at the levels of 1.40–2.31 ng g⁻¹ and 3.77–29.29 ng g⁻¹ in the sediments and sludge, respectively. The aging effect of spiked soil samples on the SAs recoveries was examined, and the results demonstrate that eight SAs could persist in five soils for 3 months. Compared with the traditional method, the proposed method could reduce the consumption of the organic solvent, shorten the sample preparation time, and increase the sample throughput.
Показать больше [+] Меньше [-]Semi-continuous sampling of health relevant atmospheric particle subfractions for chemical speciation using a rotating drum impactor in series with sequential filter sampler Полный текст
2016
Li, Fengxia | Schnelle-Kreis, Jürgen | Karg, Erwin | Cyrys, Josef | Gu, Jianwei | Orasche, Jürgen | Abbaszade, Gülcin | Peters, Annette | Zimmermann, Ralf
To achieve unattended continuous long-term (eg., 1 week) sampling of size-segregated 24-h ambient particulate matter (PM), a sampling strategy of a modified 3-stage rotating drum impactor (RDI) in series with a sequential filter sampler was introduced and verified in a field campaign. Before the field sampling, lab experiment was conducted to test the collection efficiency of the third stage of the RDI using the quartz-fiber filter (QFF) as the substrate. The measured value is 0.36 μm, which is larger than the nominal value 0.1 μm. A fast direct analysis of organic species in all size fractions (<0.36, 0.36–1, 1–2.4, and 2.4–10 μm) of 24-h ambient samples was done using in situ derivatization thermal desorption gas chromatography time-of-flight mass spectrometry (IDTD-GC-TOFMS). A few secondary originated polar markers (dicarboxylic acids, cis-pinonic acid, etc.) were introduced and evaluated using this method for the first time and quantified simultaneously with polycyclic aromatic hydrocarbons (PAH) in the filter samples (<0.36 μm). For the other RDI strip samples (0.36–1, 1–2.4, and 2.4–10 μm), PAH and levoglucosan were quantified. The comparability of two such sampler sets was verified with respect to the PM collection profile of the two RDIs as well as measured concentration of chemical compounds in each sampled size fraction, so that a future epidemiological study on the relationship between the finest PM/its chemical composition and health outcome could be carried out through parallel sampling at two sites. The internal correlations between the size-segregated organic compounds are discussed. Besides, the correlations between the size-segregated organic species and size-segregated particulate number concentration (PNC) as well as meteorological parameter are discussed as well.
Показать больше [+] Меньше [-]Dual mechanochemical immobilization of heavy metals and decomposition of halogenated compounds in automobile shredder residue using a nano-sized metallic calcium reagent Полный текст
2016
Mallampati, Srinivasa Reddy | Lee, Byoung Ho | Mitoma, Yoshiharu | Simion, Cristian
Simultaneous immobilization of heavy metals and decomposition of halogenated organic compounds in different fractions of automobile shredder residue (ASR) were achieved with a nano-sized metallic calcium through a 60-min ball milling treatment. Heavy metal (HM) immobilization and chlorinated/brominated compound (CBC) decomposition efficiencies both reached 90–100 %, after ball milling with nanometallic calcium/calcium oxide (Ca/CaO) dispersion, regardless of ASR particle size (1.0, 0.45–1.0, and 0.250 mm). Concentrations of leachable HMs substantially decreased to a level lower than the regulatory standard limits (Co and Cd 0.3 mg L⁻¹; Cr 1.5 mg L⁻¹; Fe, Pb, and Zn 3.0 mg L⁻¹; Mn and Ni 1 mg L⁻¹) proposed by the Korean hazardous waste elution standard regulatory threshold. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) element maps/spectra showed that while the amounts of HMs and CBCs detectable in ASR significantly decreased, the calcium mass percentage increased. X-ray powder diffraction (XRD) patterns indicate that the main fraction of enclosed/bound materials on ASR includes Ca-associated crystalline complexes that remarkably inhibit HM desorption and simultaneously transform dangerous CBCs into harmless compounds. The use of a nanometallic Ca/CaO mixture in a mechanochemical process to treat hazardous ASR (dry conditions) is an innovative approach to remediate cross-contaminated residues with heavy metals and halogenated compounds.
Показать больше [+] Меньше [-]Release of silver nanoparticles from fabrics during the course of sequential washing Полный текст
2016
Limpiteeprakan, Pawena | Babel, Sandhya | Lohwacharin, Jenyuk | Takizawa, S (Satoshi)
Increasing use of silver nanoparticles (AgNPs) in consumer products has raised concerns about the potential impacts of AgNPs on the environment. This study aimed to assess the potential release of AgNPs from textiles due to sequential washing. Different types of fabrics including cotton, polyester (PES), and cotton blended with PES (called TC) were coated with 4–5 nm AgNPs and used in the sequential washing experiments with Milli-Q water at neutral pH and with commercial detergent at alkaline pH. Similar experiments were also run-on consumer textile products washed with Milli-Q water. The percent Ag remaining on the products after washing was also investigated. The initial Ag contents ranged from 254 to 350 μg Ag/g of the product in lab-prepared fabrics and from 1.2 to 44 μg Ag/g of the product in consumer products. After 20 wash cycles, 48 to 72 % of Ag was lost from the prepared fabrics washed with Milli-Q water, while a greater loss of 84–94 % of Ag occurred after washing the prepared fabrics with commercial detergent. The Ag released during the washing process is present dominantly in particulate form. In the consumer products after 20 washes with Milli-Q water, the percent Ag remaining was found to be around 46 to 70 %. Statistical analysis of the Ag release rate between consumer products and lab-prepared fabrics in Milli-Q washing water by independent t test showed no significant difference after 20 washing cycles (p > 0.05).
Показать больше [+] Меньше [-]Response of two cultivars of Phaseolus vulgaris L. (French beans) plants exposed to enhanced UV-B radiation under mountain ecosystem Полный текст
2016
Raghuvanshi, Rashmi | Sharma, Rajesh Kumar
Enhanced solar ultraviolet-B (UV-B) irradiance resulting from depletion in the ozone layer has the potential to cause detrimental effects on plants. Higher altitudes tend to receive higher doses of ambient UV-B radiation. The present study was carried out to assess the effects of enhanced UV-B (ambient + 10.2 kJ m⁻² day⁻¹) radiation on two cultivars of Phaseolus vulgaris L. (cv. Pusa Himlata and Pusa Parvati) at growth, physiological, and biochemical levels grown under mountain ecosystem. The magnitudes of negative effects of enhanced UV-B radiation were found more in Pusa Parvati as compared to Pusa Himlata. Non-enzymatic (total phenolics and flavonoids content) and enzymatic antioxidants (superoxide dismutase, catalase, and peroxidase) were increased in both cultivars at both the ages of growth but increase was found more in Pusa Himlata as compared to Pusa Parvati. The study further showed that the economic yield of Pusa Himlata and Pusa Parvati was decreased by 14 and 44 %, respectively, due to enhanced UV-B radiation. The higher decrease in the economic yield of Pusa Parvati depicted that increased amounts of total flavonoids content and stimulation of their antioxidant defense mechanism via increasing the activities of enzymatic antioxidants were not able to completely detoxify the produced reactive oxygen species under enhanced UV-B radiation and made it more sensitive to applied stress. From the present study, it can be concluded that enhanced UV-B radiation in the mountain areas of the Indian Himalayan Regions could be one of the environmental causes for lower yields of agricultural crops. Cultivation of P. vulgaris L. cv. Pusa Himlata should be promoted at higher altitudes of the Indian Himalayan Regions.
Показать больше [+] Меньше [-]Parabens abatement from surface waters by electrochemical advanced oxidation with boron doped diamond anodes Полный текст
2016
Domínguez, Joaquín R. | Muñoz-Peña, Maria J. | González, Teresa | Palo, Patricia | Cuerda-Correa, Eduardo M.
The removal efficiency of four commonly-used parabens by electrochemical advanced oxidation with boron-doped diamond anodes in two different aqueous matrices, namely ultrapure water and surface water from the Guadiana River, has been analyzed. Response surface methodology and a factorial, composite, central, orthogonal, and rotatable (FCCOR) statistical design of experiments have been used to optimize the process. The experimental results clearly show that the initial concentration of pollutants is the factor that influences the removal efficiency in a more remarkable manner in both aqueous matrices. As a rule, as the initial concentration of parabens increases, the removal efficiency decreases. The current density also affects the removal efficiency in a statistically significant manner in both aqueous matrices. In the water river aqueous matrix, a noticeable synergistic effect on the removal efficiency has been observed, probably due to the presence of chloride ions that increase the conductivity of the solution and contribute to the generation of strong secondary oxidant species such as chlorine or HClO/ClO ⁻. The use of a statistical design of experiments made it possible to determine the optimal conditions necessary to achieve total removal of the four parabens in ultrapure and river water aqueous matrices.
Показать больше [+] Меньше [-]Cat serum contamination by phthalates, PCBs, and PBDEs versus food and indoor air Полный текст
2016
Braouezec, Clélie | Enriquez, Brigitte | Blanchard, Martine | Chevreuil, Marc | Teil, Marie-Jeanne
A wide variety of endocrine disrupting compounds (EDCs) with semi-volatile properties are emitted to indoor air and, thus, humans might get exposed to these compounds. Pet cats spend the major part of their lifetime at home and might integrate indoor contamination so that they could mirror the human exposure. Three classes of EDCs, polybromodiphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and phthalates (PAEs), were simultaneously considered and quantified in the serum of cats (Felis silvestris catus) living in the Paris area (France). The main compound concentrations by decreasing importance order were as follows: for PAEs, di-n-butyl phthalate (79,900 ng L⁻¹) next di-iso-butyl phthalate (53,200 ng L⁻¹), di-iso-nonyl phthalate (43,800 ng L⁻¹), and di-ethylhexyl phthalate (32,830 ng L⁻¹); for PCBs, CB153 (1378 ng L⁻¹) next CB52 (509 ng L⁻¹), CB101 (355 ng L⁻¹), CB110 (264 ng L⁻¹), and CB118 (165 ng L⁻¹); and for PBDEs, BDE 153/154 (35 ng L⁻¹) next BDE47 (10.7 ng L⁻¹). Total serum concentrations as mean ± standard deviation were 107 ± 98 μg L⁻¹ for ∑9PAEs, 2799 ± 944 ng L⁻¹ for ∑19PCBs, and 56 ± 21 ng L⁻¹ for ∑9BDEs. The three chemical groups were found in cat food: 0.088 ng g⁻¹ for ∑9BDEs, 1.7 ng g⁻¹ for ∑19PCBs, and 2292 ng g⁻¹ for ∑9PAEs and in indoor air: 0.063 ng m⁻³ for ∑9BDEs, 1.5 ng m⁻³ for ∑19PCBs, and 848 ng m⁻³ for ∑9PAEs. Contaminant intake by food ingestion was approximately 100-fold higher than that by indoor air inhalation.
Показать больше [+] Меньше [-]Occurrence of Legionella in wastewater treatment plants linked to wastewater characteristics Полный текст
2016
Caicedo, C. | Beutel, S. | Scheper, T. | Rosenwinkel, K. H. | Nogueira, R.
In recent years, the occurrence of Legionella in wastewater treatment plants (WWTP) has often been reported. However, until now there is limited knowledge about the factors that promote Legionella’s growth in such systems. The aim of this study was to investigate the chemical wastewater parameters that might be correlated to the concentration of Legionella spp. in WWTP receiving industrial effluents. For this purpose, samples were collected at different processes in three WWTP. In 100 % of the samples taken from the activated sludge tanks Legionella spp. were detected at varying concentrations (4.8 to 5.6 log GU/mL) by the quantitative real-time polymerase chain reaction method, but not by the culture method. Statistical analysis with various parameters yielded positive correlations of Legionella spp. concentration with particulate chemical oxygen demand, Kjeldahl nitrogen and protein concentration. Amino acids were quantified in wastewater and activated sludge samples at concentrations that may not support the growth of Legionella, suggesting that in activated sludge tanks this bacterium multiplied in protozoan hosts.
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