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621.
The identification of degradation products generated upon photolysis of estrone (E1), a natural estrogenic hormone, under simulated UV irradiation conditions was addressed by the use of LC-Q-TOF mass spectrometry. The structures of the main degradation products were elucidated, demonstrating how the use of model molecules 5,6,7,8-tetrahydro-2-naphtol (THN), 2-methylcyclopentanone (MCP), labeled molecule estrone D(4) (E1-D(4)), the investigation of the fragmentation pathways of the parent E1, the concurrent use of CID and exact mass measurements permit the characterization of structural modifications induced by photodegradation processes. In the present study, we identified nine major by-products of which seven photoproducts correspond to E1H(+) modified in positions other than the C-2, C-4 and C-16 of E1. Most of them showed one to three additional hydroxylations preferentially located on the aromatic ring of the parent E1, which confirms that these products may present environmental risk. Applications to real water samples have been conducted to extend the validity of the present study to environmental samples. 相似文献
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623.
Céline Liaud Michel Brucher Claude Schummer Clara Coscollà Hélène Wolff Jean-Jacques Schwartz 《Journal of environmental science and health. Part. B》2016,51(10):703-714
Atmospheric samples have been collected between 14 March and 12 September 2012 on a 2-week basis (15 days of sampling and exchange of traps each 7 days) in Strasbourg (east of France) for the analysis of 43 pesticides. Samples (particle and gas phases) were separately extracted using Accelerated Solvent Extraction (ASE) and pre-concentrated by Solid Phase Micro-Extraction (SPME) before analysis by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Four SPME consecutive injections at distinct temperatures were made in order to increase the sensitivity of detection for the all monitored pesticides. Currently used detected pesticides can be grouped in four classes; those used in maize crops (acetochlor, benoxacor, dicamba, s-metolachlor, pendimethalin, and bromoxynil), in cereal crops (benoxacor, chlorothalonil, fenpropimorph, and propiconazole), in vineyards (tebuconazole), and as herbicides for orchards, meadows of green spaces (2,4-MCPA, trichlopyr). This is in accordance with the diversity of crops found in the Alsace region and trends observed are in accordance with the period of application of these pesticides. Variations observed permit also to demonstrate that the long time sampling duration used in this study is efficient to visualize temporal variations of airborne pesticides concentrations. Then, long time high-volume sampling could be a simple method permitting atmospheric survey of atmospheric contamination without any long analysis time and consequently low cost. 相似文献
624.
The seasonal treatment efficiency of a pilot-scale constructed wetland system located outdoors in a semi-arid, temperate climate was evaluated for graywater in a comprehensive, 1-year study. The system consisted of two wetland beds in series--a free water surface bed followed by a subsurface flow bed. Water quality monitoring evaluated organics, solids, nutrients, microbials, and surfactants. The results showed that the wetland substantially reduced graywater constituents during fall, spring, and summer, including biochemical oxygen demand (BOD) (92%), total nitrogen (85%), total phosphorus (78%), total suspended solids (TSS) (73%), linear alkylbenzene sulfonate (LAS) surfactants (94%), and E. coli (1.7 orders of magnitude). Except for TSS, lower removals of graywater constituents were noted in winter--BOD (78%), total nitrogen (64%), total phosphorus (65%), LAS (87%), and E. coli (1.0 order), indicating that, although wetland treatment slowed during the winter, the system remained active, even when the average water temperature was 5.2 +/- 4.5 degrees C. 相似文献
625.
Metian M Warnau M Teyssié JL Bustamante P 《Journal of environmental radioactivity》2011,102(6):543-550
In order to understand the bioaccumulation of 241Am and 134Cs in scallops living in sediments, the uptake and depuration kinetics of these two elements were investigated in the king scallop Pecten maximus exposed via seawater, food, or sediment under laboratory conditions. Generally, 241Am accumulation was higher and its retention was stronger than 134Cs. This was especially obvious when considering whole animals exposed through seawater with whole-body concentration factors (CF7d) of 62 vs. 1, absorption efficiencies (A0l) of 78 vs. 45 for seawater and biological half-lives (Tb½l) of 892 d vs. 22 d for 241Am and 134Cs, respectively. In contrast, following a single feeding with radiolabelled phytoplankton, the assimilation efficiency (AE) and Tb½l of 134Cs were higher than those of 241Am (AE: 28% vs. 20%; Tb½l: 14 d vs. 9 d). Among scallop tissues, the shells always contained the higher proportion of the total body burden of 241Am whatever the exposure pathway. In contrast, the whole soft parts presented the major fraction of whole-body burden of 134Cs, which was generally associated with muscular tissues. Our results showed that the two radionuclides have contrasting behaviors in scallops, in relation to their physico-chemical properties. 相似文献
626.
Drouillet-Pinard P Boisset M Periquet A Lecerf JM Casse F Catteau M Barnat S 《Journal of environmental science and health. Part. B》2011,46(1):84-91
The increase of fruit and vegetable (F&V) intake contributes to the prevention of chronic diseases, but could also significantly increase pesticide exposure and may thus be of health concern. Following a previous pesticide exposure assessment study, the present study was carried out to determine actual levels of pesticides within 400 g of F&V intake and to evaluate consumer risk. Forty-three Active Substances (AS) exceeding 10 % of the Acceptable Daily Intake (ADI) in balanced menus established for our previous theoretical study were considered. Fifty-six pooled food samples were analyzed: 28 fruit samples and 28 vegetable samples. Pesticide values were compared to Maximum Residue Levels (MRL) and to the "toxicological credit" derived from ADI. It was observed that 23 out of the 43 retained AS were never detected, 5 were detected both in F&V samples, 12 only in fruits and 3 only in vegetables. The most frequently detected AS were carbendazim, iprodione and dithiocarbamates. When detected, AS were more frequently found in fruit samples (74 %) than in vegetable samples (26 %). A maximum of 3 AS were detected at once in a given sample. Overall, we observed 8 and 14 overruns of the MRL in 1204 measures in pooled vegetable and fruit samples, respectively (0.7 % and 1.2 % of cases, respectively). Chronic exposure for adults was the highest for dithiocarbamates but did not exceed 23.7 % of the ADI in F&V. It was concluded that raising both F&V consumption up to 400 g/day (~5 F&V/day) according to recommendations of the national health and nutrition plan, does not induce pesticide overexposure and should not represent a risk for the consumer. 相似文献
627.
The problem of forest degradation and loss has become the concern of many countries. To address this challenge, some collaborate in sustainable forest management. The most successful outcomes, however, are observed where local participation is an essential part of conservation efforts. In Ghana, forests have experienced various degrees of exploitation over the years, resulting in their ecological decline. Despite its designation as a protected area for biodiversity and ecosystem services, the Atewa Range Forest Reserve in Ghana has been significantly impacted by deforestation, illegal mining, and other destructive activities. The purpose of this paper is to examine ecologically based management approaches that could be adopted to generate beneficial outcomes for all forest stakeholders and actors in Ghana. The study sampled forest stakeholders in Kwabeng, the administrative capital of the Atewa West District, to understand forest governance challenges and outline strategies for overcoming them. The study revealed that a bottom-up all-inclusive approach to managing forest resources is necessary. This paper, therefore, proposes an integrated forest governance that prioritizes the UN Sustainable Development Goal 15—Life on Land-related to forest preservation. 相似文献
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