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结果 3031-3040 的 4,033
The use of ALS, botanical, and soil data to monitor the environmental hazards and regeneration capacity of areas devastated by highway construction
2016
Kopeć, Dominik | Woziwoda, Beata | Forysiak, Jacek | Sławik, Łukasz | Ptak, Agnieszka | Charążka, Edyta
The impact of viaduct construction on the vegetation of a river valley was studied in Central Poland (Natura 2000 site PLH100006). The research aimed at assessing the suitability of ALS (airborne laser scanning), soil, and botanical data for monitoring the environmental effects of right-of-way reclamation 1 year after the road construction. Based on the data mentioned above, the following problems were identified: changes in topography and hydrological conditions of the valley as a result of improper land levelling, the use of inadequate soil for reclamation, no spontaneous regeneration of natural vegetation along the entire right-of-way, as well as the abundant occurrence of invasive species. The results of analysis were used to define strategies for mitigation of adverse impacts of the viaduct construction.
显示更多 [+] 显示较少 [-]Acute crack cocaine exposure induces genetic damage in multiple organs of rats
2016
Moretti, Eduardo Gregolin | Quispe Yujra, Veronica | Claudio, Samuel Rangel | Silva, Marcelo Jose Dias | Vilegas, Wagner | Pereira, Camilo Dias Seabra | de Oliveira, Flavia | Ribeiro, Daniel Araki
Crack cocaine is a very toxic product derived from cocaine. The aim of this study was to evaluate genetic damage in multiple organs of rats following acute exposure to crack cocaine. A total of 20 Wistar rats were distributed into four groups (n = 5), as follows: 0, 4.5, 9, and 18 mg/kg body weight (b.w.) of crack cocaine administered by intraperitoneal route (i.p.). All animals were killed 24 h after intraperitoneal (i.p.) injection. The results showed that crack cocaine increased the number of micronucleated cells in bone marrow cells exposed to 18 mg/kg crack cocaine (p < 0.05). Peripheral blood and liver cells presented genetic damage as depicted by single cell gel (comet) assay at 9 and 18 mg/kg doses (p < 0.05). Immunohistochemistry data revealed significant increase in 8-hydroxy-20-deoxyguanosine (8-OHdG) immunoexpression in hepatocytes of animals exposed to crack cocaine at 9 and 18 mg/kg (p < 0.05) when compared with negative controls. Taken together, our results demonstrate that crack cocaine is able to induce genomic damage in multiple organs of Wistar rats.
显示更多 [+] 显示较少 [-]Human metabolites and transformation products of cyclophosphamide and ifosfamide: analysis, occurrence and formation during abiotic treatments
2016
Česen, Marjeta | Kosjek, Tina | Busetti, Francesco | Kompare, Boris | Heath, Ester
This study describes a gas chromatography-mass spectrometry analytical method for the analysis of cytostatic cyclophosphamide (CP), ifosfamide (IF) and their selected metabolites/transformation products (TPs): carboxy-cyclophosphamide (carboxy-CP), keto-cyclophosphamide (keto-CP) and 3-dechloroethyl-ifosfamide/N-dechloroethyl-cyclophosphamide (N-decl-CP) in wastewater (WW). Keto-cyclophosphamide, CP and IF were extracted with Oasis HLB and N-decl-CP and carboxy-CP with Isolute ENV+ cartridges. Analyte derivatization was performed by silylation (metabolites/TPs) and acetylation (CP and IF). The recoveries and LOQs of the developed method were 58, 87 and 103 % and 77.7, 43.7 and 6.7 ng L⁻¹ for carboxy-CP, keto-CP and N-decl-CP, respectively. After validation, the analytical method was applied to hospital WW and influent and effluent samples of a receiving WW treatment plant. In hospital WW, levels up to 2690, 47.0, 13,200, 2100 and 178 ng L⁻¹ were detected for CP, IF, carboxy-CP, N-decl-CP and keto-CP, respectively, while in influent and effluent samples concentrations were below LOQs. The formation of TPs during abiotic treatments was also studied. Liquid chromatography-high-resolution mass spectrometry was used to identify CP and IF TPs in ultrapure water, treated with UV and UV/H₂O₂. UV treatment produced four CP TPs and four IF TPs, while UV/H₂O₂ resulted in five CPs and four IF TPs. Besides already known TPs, three novel TPs (CP-TP138a, imino-ifosfamide and IF-TP138) have been tentatively identified. In hospital WW treated by UV/O₃/H₂O₂, none of the target metabolites/TPs resulted above LOQs.
显示更多 [+] 显示较少 [-]Effects of dispersed oil exposure on biomarker responses and growth in juvenile wolfish Anarhichas denticulatus
2016
Sandrini-Neto, L. | Geraudie, P. | Santana, M.S. | Camus, L.
This study evaluated the sensitivity of the wolfish Anarhichas denticulatus exposed to crude oil, comparing the effects of mechanically dispersed versus chemically dispersed oil using sub-lethal endpoints. To test the toxicity of this controversial technique, two experiments involving exposure of the organisms for 48 h were conducted. The first experiment assessed the effects of oil exposure on biomarker responses. The second experiment monitored the growth of juveniles over 5 weeks after exposure. Overall, this study demonstrated that polycyclic aromatic hydrocarbon (PAH) biliary metabolites, ethoxyresorufin-O-deethylase (EROD), and acetylcholinesterase (AChE) are appropriate biomarkers to assess exposure of A. denticulatus. Growth rate, both in length and weight, was significantly higher in control compared to oil exposure treatments. The lack of differences between chemically and mechanically dispersed oils in biomarker response and growth suggests that dispersant application is no more toxic than the natural oil dispersion. The results indicate the potential for population-level effects resulting from exposure to oil.
显示更多 [+] 显示较少 [-]Mustard plant ash: a source of micronutrient and an adsorbent for removal of 2,4-dichlorophenoxyacetic acid
2016
Trivedi, Nikhilesh S. | Mandavgane, Sachin A. | Kulkarni, B. D.
The work highlights the utilization of an agricultural waste mustard plant ash (MPA) as a soil additive and an adsorbent. MPA was characterized by X-ray fluorescence (XRF), energy-dispersive X-ray spectroscopy (EDX), proximate analysis, CHNS analysis, Brunauer–Emmett–Teller (BET) surface area analysis, zeta potential measurements, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). XRF analysis confirmed the presence of CaO (31.35 %), K₂O (18.55 %), and P₂O₅ (6.99 %), all of which act as micronutrients to plants. EDX also confirms high amount of elemental O, Ca, K, and P. The adsorptive ability of MPA was investigated using a commonly used herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), as a representative chemical. Batch adsorption experiments were conducted to study the effect of different operational parameters such as adsorbent dose, initial 2,4-D concentration, contact time, and temperature on the adsorption process. Data from experiments were fitted to various kinetic and isothermal models. The pseudo-second-order kinetic model was found to show the best fit (R ² > 0.99), with the highest k ₂ value of the order 10⁵. Based on the study results, dosage of MPA/hectare for different crops has been recommended for effective removal of 2,4-D. To our knowledge, this is the first study in which MPA has been characterized in detail and investigated for dual applications (as an adsorbent and as a soil additive).
显示更多 [+] 显示较少 [-]From immunotoxicity to carcinogenicity: the effects of carbamate pesticides on the immune system
2016
Dhouib, Ines | Jallouli, Manel | Annabi, Alya | Marzouki, Soumaya | Gharbi, Najoua | Elfazaa, Saloua | Lasram, Mohamed Montassar
The immune system can be the target of many chemicals, with potentially severe adverse effects on the host’s health. In the literature, carbamate (CM) pesticides have been implicated in the increasing prevalence of diseases associated with alterations of the immune response, such as hypersensitivity reactions, some autoimmune diseases and cancers. CMs may initiate, facilitate, or exacerbate pathological immune processes, resulting in immunotoxicity by induction of mutations in genes coding for immunoregulatory factors and modifying immune tolerance. In the present study, direct immunotoxicity, endocrine disruption and inhibition of esterases activities have been introduced as the main mechanisms of CMs-induced immune dysregulation. Moreover, the evidence on the relationship between CM pesticide exposure, dysregulation of the immune system and predisposition to different types of cancers, allergies, autoimmune and infectious diseases is criticized. In addition, in this review, we will discuss the relationship between immunotoxicity and cancer, and the advances made toward understanding the basis of cancer immune evasion.
显示更多 [+] 显示较少 [-]The influence of chemically enhanced backwash by-products (CEBBPs) on water quality in the coagulation–ultrafiltration process
2016
Zhang, Yue | Zhao, Xinhua | Zhang, Xinbo | Sun, Jingmei
This study was conducted to investigate the typical types of chemically enhanced backwash by-products (CEBBPs) produced in the chemically enhanced backwash (CEB) process and the influence of CEB parameters on typical CEBBPs in the coagulation–ultrafiltration process. Health risk assessment was applied to assess the potential adverse health effect from exposure to effluent after the optimal CEB. The results indicated that backwash reagent of sodium hypochlorite reacted with organic matter to produce CEBBPs, including 12 species of volatile halogenated organic compounds (VHOCs) and 9 species of haloacetic acids (HAAs) during CEB process. The amount of HAAs was higher than that of VHOCs indicating that the content of primary HAA precursor (hydrophilic organic matter) was high in raw surface water and the coagulation process could not lower the hydrophilic organic matter concentration. After comprehensive consideration of the influence of single factors on the CEBBP formation and membrane cleaning effect, the optimal CEB parameters was 4 min of backwash duration, 120 min of backwash interval, 20 L/(m²·h) of backwash flux, and 25 mg/L of reagent concentration. Under the optimum CEB cleaning parameters, the effluent did not pose non-carcinogenic risk to local residents but could pose potential carcinogenic risk.
显示更多 [+] 显示较少 [-]Effects of sandy vs muddy sediments on the vertical distribution of microphytobenthos in intertidal flats of the Fraser River Estuary, Canada
2016
Yin, Kedong | Zetsche, Eva-Maria | Harrison, Paul J.
Benthic algae or microphytobenthos (MPB) in intertidal flats play an important role in the sediment and overlying water ecosystems. We hypothesize that there are effects of sediment texture on the vertical distribution of MPB using chlorophyll a (chl a) as a proxy for MPB biomass and present results over a 2.5-year period. Four sites were sampled monthly: two sandy sites (A10 and A12) and two muddy sites (A0 and A14) on the intertidal flats of the Fraser River Estuary. At the two sandy sites, pigments were distributed down to 10 cm. High ratios of depth-integrated chl a to phaeopigments suggest that the chl a had been recently buried. In contrast, at the muddy sites, pigments were limited to the top 4 cm, with MBP in the top 1 cm contributing up to 60 % of the whole sediment core pigments. As a result, the depth-integrated chl a values were on average 2,044 mg m–² (160–4,200) at A10 and 882 mg m⁻² (183–2,569) at A12, the two sandy sites, and much higher than at the two muddy sites where averages of 84 mg m⁻² (41–174) and 235 mg m⁻² (77–854) were measured at A0 and A14, respectively. Despite these lower concentrations at the muddy sites than at the sandy sites, particulate organic carbon (POC) and nitrogen (PON) concentrations showed a homogenous vertical distribution at the two sandy sites. Such a homogeneous vertical distribution of chl a, POC, and PON suggests that vertical transport mechanisms were actively transporting organic material into and out of the sediment. These results suggest that MBP on sandy sediments play a very active role in providing food for herbivores and are interacting with the overlying water column in the sediment-water exchange processes during tidal cycles.
显示更多 [+] 显示较少 [-]Stakeholder consultations and opportunities for integrating socio-behavioural factors into the pesticide risk analysis process
2016
Calliera, Maura | Marchis, Alex | Sacchettini, Gabriele | Capri, Ettore
The pesticide risk analysis process is well regulated in the EU, especially in relation to placing on the market authorisation procedures, but in order to avoid risks for human health and environment in the use phase, information on how these substances are employed and on socio-behavioural factors that can influence the exposure have to be taken into account. To better explore reasons about the gap between risk assessment and risk management, within the EU FP7 Health and Environmental Risks: Organisation, Integration and Cross-fertilisation of Scientific Knowledge (HEROIC) project, a stepwise stakeholder’s consultation process was developed using a mixed approach in two different phases (survey and roundtable). We elicited stakeholder views regarding factors that could limit the pesticide risk assessment phase linked on how the knowledge is produced and the way the data are used in risk management and in risk communication, also taking into account qualitative factors such as responsibility, trust and behaviours, which could have impact on risk assessment policies. Activities deployed indicate that some changes and interaction are needed to better define the problems at the formulation stage, and the type of information risk assessor has to provide, to better inform risk manager in addressing different societal needs, to strengthen the credibility of the process of risk assessment and improve the effectiveness of policies. Integrations between disciplines may initially increase the complexity but in turn will provide a better and more useful estimation of the risk, reinforce transparency and drive a more efficient use of risk management resources.
显示更多 [+] 显示较少 [-]Remediation of radiocesium-contaminated liquid waste, soil, and ash: a mini review since the Fukushima Daiichi Nuclear Power Plant accident
2016
Ding, Dahu | Zhang, Zhenya | Lei, Zhongfang | Yang, Yingnan | Cai, Tianming
The radiation contamination after the Fukushima Daiichi Nuclear Power Plant accident attracts considerable concern all over the world. Many countries, areas, and oceans are greatly affected by the emergency situation other than Japan. An effective remediation strategy is in a highly urgent demand. Though plenty of works have been carried out, progressive achievements have not yet been well summarized. Here, we review the recent advances on the remediation of radiocesium-contaminated liquid waste, soil, and ash. The overview of the radiation contamination is firstly given. Afterwards, the current remediation strategies are critically reviewed in terms of the environmental medium. Special attentions are paid on the adsorption/ion exchange and electrically switched ion exchange methods. Finally, the present review outlines the possible works to do for the large-scale application of the novel remediation strategies.
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