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41.
In the present study were two favorite edible fish species for local residents, i.e., mandarin fish and crawfish, collected from the Shanghai market and analyzed for selected organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), hexabromocyclododecane (HBCDD), polybrominated diphenyl ethers (PBDEs) and methoxylated PBDEs (MeO-PBDEs). Efforts were also made to identify the potential sources of these contaminants. Comparable concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and HBCDD were found in muscle tissue of mandarin fish from Guangdong (GDF), the Pearl River Delta and from Taihu Lake (TLF), the Yangtze River Delta. Levels of chlordanes, PCBs and PBDEs were about one magnitude lower in TLF compared to GDF. The concentrations of OCPs in the butter-like gland of the crawfish (CFB) were 2-5 times of those in the crawfish muscle (CFM) while concentrations of PCBs, PBDEs and MeO-PBDEs were comparable. The different patterns and levels of chlorinated and brominated organohalogen contaminants seen in mandarin fish from GDF and TLF indicates that different types of chemicals might be used in the two delta regions. The present study also shows a good correlation between the concentrations of hexachlorobenzene (HCB) and pentachloroanisol (PCA) in fish for the first time. Fish consumption limits based on chemical contaminants with non-carcinogenic effects were calculated. The estimated maximum daily consumption limit for GDF, TLF, CFM and CFB were 1.5, 2.6, 3.7 and 0.08 kg, respectively, indicating no significant risk regarding the persistent organic pollutants measured in the present study.  相似文献   
42.
Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are used in large quantities. They are persistent and found in measurable levels in human serum around the world. They have been associated with developmental, hepatic, and carcinogenic effects in animal studies. The aim of the present study was to describe levels of PFCs in serum among Inuits from Greenland and inhabitants from Warsaw, Poland and Kharkiv, Ukraine. Furthermore, the aim was to define social- and lifestyle related determinants of exposure for these compounds. Serum levels of seven PFCs were analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The concentrations of PFOS and PFOA were the highest of all PFCs in all three populations with a total amount of almost 90% of the PFCs. The mean levels of PFOS and PFOA were in the Greenlandic Inuits 52 and 4.8 ng mL(-1), in Poland 19 and 5.2 ng mL(-1), and in Ukraine 8.1 and 1.9 ng mL(-1), respectively. Thus, levels of PFCs in the serum of Inuits on Greenland were among the highest described in a general population whereas the levels in Poland were similar to other industrialized countries. The exposure in Ukraine was rather low. In the Greenlandic Inuit population, intake of seafood, tea, age and area of living were significant determinants of PFOS concentrations and explained about 22% of the variation. For the other populations no strong determinants were found.  相似文献   
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Chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate) was applied with three different formulations on oranges, peaches, tomatoes, wine and table grapes, and its behaviour was evaluated after field treatment. The formulations applied were emulsifiable concentrates (EC), microencapsulates (ME), and wettable granules (WG). The residues were similar in all crops studied in the EC and WG experiments, except peaches with WG treatment, the residue amount was lower than EC values. Tomatoes which were grown in greenhouse showed similar residues in all treatments just after treatment. Wine and table grapes showed different decline curves in the EC experiments ascribable to the different growing technology. Instrumental limit of determination (LOD) and limit of quantification (LOQ) for all matrices were 0.01, and 0.03 mg kg?1, respectively. Repeated treatments showed that Chlorpyrifos can accumulate leading to residue levels at the preharvest interval (PHI) over the maximum residue level (MRL), especially on oranges and peaches. Among the formulates used ME showed the higher risk of residues over the MRL at harvest.  相似文献   
46.
Temporal variations of atmospheric aerosol in four European urban areas   总被引:1,自引:0,他引:1  

Purpose

The concentrations of PM10 mass, PM2.5 mass and particle number were continuously measured for 18 months in urban background locations across Europe to determine the spatial and temporal variability of particulate matter.

Methods

Daily PM10 and PM2.5 samples were continuously collected from October 2002 to April 2004 in background areas in Helsinki, Athens, Amsterdam and Birmingham. Particle mass was determined using analytical microbalances with precision of 1 ??g. Pre- and post-reflectance measurements were taken using smoke-stain reflectometers. One-minute measurements of particle number were obtained using condensation particle counters.

Results

The 18-month mean PM10 and PM2.5 mass concentrations ranged from 15.4 ??g/m3 in Helsinki to 56.7 ??g/m3 in Athens and from 9.0 ??g/m3 in Helsinki to 25.0 ??g/m3 in Athens, respectively. Particle number concentrations ranged from 10,091 part/cm3 in Helsinki to 24,180 part/cm3 in Athens with highest levels being measured in winter. Fine particles accounted for more than 60% of PM10 with the exception of Athens where PM2.5 comprised 43% of PM10. Higher PM mass and number concentrations were measured in winter as compared to summer in all urban areas at a significance level p?Conclusions Significant quantitative and qualitative differences for particle mass across the four urban areas in Europe were observed. These were due to strong local and regional characteristics of particulate pollution sources which contribute to the heterogeneity of health responses. In addition, these findings also bear on the ability of different countries to comply with existing directives and the effectiveness of mitigation policies.  相似文献   
47.
Ecotoxicity evaluation of selected sulfonamides   总被引:6,自引:0,他引:6  
Sulfonamides (SAs) are a group of antibiotic drugs widely used in veterinary medicine. The contamination of the environment by these pharmaceuticals has raised concern in recent years. However, knowledge of their (eco)toxicity is still very basic and is restricted to just a few of these substances. Even though their toxicological analysis has been thoroughly performed and ecotoxicological data are available in the literature, a systematic analysis of their ecotoxicological potential has yet to be carried out. To fill this gap, 12 different SAs were chosen for detailed analysis with the focus on different bacteria as well as non-target organisms (algae and plants). A flexible (eco)toxicological test battery was used, including enzymes (acetylcholinesterase and glutathione reductase), luminescent marine bacteria (Vibrio fischeri), soil bacteria (Arthrobacter globiformis), limnic unicellular green algae (Scenedesmus vacuolatus) and duckweed (Lemna minor), in order to take into account both the aquatic and terrestrial compartments of the environment, as well as different trophic levels. It was found that SAs are not only toxic towards green algae (EC50 = 1.54-32.25 mg L−1) but have even stronger adverse effect on duckweed (EC50 = 0.02-4.89 mg L−1) than atrazine - herbicide (EC50 = 2.59 mg L−1).  相似文献   
48.
It was reported the adsorption of As(III) on the surface of the chitosan-Fe-crosslinked complex. Theoretical correlation of the experimental equilibrium adsorption data for As(III)/Ch-Fe system is best explained by the non-linearized form Langmuir-Freundlich isotherm model. At optimum conditions, pH 9.0, the maximum adsorption capacity, calculated using the Langmuir-Freundlich isotherm model was 13.4 mg g−1. The adsorption kinetics of As(III) onto Ch-Fe are described by the pseudo-first-order kinetic equation. The results of the Mössbauer spectroscopy showed that there is no redox process on the surface of the adsorbent.  相似文献   
49.
he analysis in this paper was based on data obtained from 80 male participants, aged 29-65. Critical Flicker Fusion Frequency (CFFF) was measured using the Flicker Test. The Formal Characteristics of Behaviour-Temperament Inventory (FCB-TI) by Strelau and Zawadzki (1993) was used for temperamental characteristics. The results of statistical analysis did not confirm a hypothesis about the correlation between CFFF level and 3 temperamental characteristics. There were no immediate relationships among those variables. Correlation was observed when the CFFF coefficient of variance, instead of average CFFF values, was taken into account, especially in the case of a division into 2 groups of participants, “reckless” and “unsure.” It could be interesting to check in the future a hypothesis about the stability of selected types of reactions.  相似文献   
50.
Abstract

Aim. The aim of this study was to evaluate working conditions with a notebook computer (notebook) as a potential cause of musculoskeletal disorders. Material and methods. The study had 2 stages. The first one was a questionnaire survey among 300 notebook users. The next stage was an expert analysis of 53 randomly selected workstations. The questionnaire survey included questions about the participants, their working conditions, work organization and also duration of work with a notebook. Results and conclusions. The results of the research showed that most examined operators used a notebook as a basic working tool. The most important irregularities included an unadjustable working surface, unadjustable height of the seat pan and backrest, unadjustable height and distance between the armrests and no additional ergonomic devices (external keyboard, docking station, notebook stand or footstool).  相似文献   
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