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861.
Screening of pesticides for environmental partitioning tendency 总被引:1,自引:0,他引:1
862.
Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator,Pteris vittata L 总被引:6,自引:0,他引:6
Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As uptake from the ASC soil. Elevated As uptake in the compost-treated CCA soil was related to the increase of soil water-soluble As and As(V) transformation into As(III). Reduced As uptake in the ASC soil may be attributed to As adsorption to the compost. Chinese brake fern took up As mainly from the iron-bound fraction in the CCA soil and from the water-soluble/exchangeable As in the ASC soil. Without ferns for As adsorption, compost and phosphate amendments increased As leaching from the CCA soil, but had decreased leaching with ferns when compared to the control. For the ASC soil, treatments reduced As leaching regardless of fern presence. This study suggest that growing Chinese brake fern in conjunction with phosphate amendments increases the effectiveness of remediating As-contaminated soils, by increasing As uptake and decreasing As leaching. 相似文献
863.
Nygren O Gustavsson B Ström L Eriksson R Jarneborn L Friberg A 《Journal of environmental monitoring : JEM》2002,4(5):739-742
Systems for the preparation and administration of drugs are designed to ensure that the drug is not contaminated. They do not necessarily consider the work environment for the medical staff and new techniques are therefore desirable. The aim of this work is to compare a new closed system for the preparation and administration of drugs with the traditional technique with regard to airborne emission and surface spillage of drugs. Platinum, determined using adsorptive voltammetry, was used as the tracer for airborne emission. Air samples were collected during the preparation and administration, and the collected platinum on the filters was determined by adsorptive voltammetry. For determination of spills and leakage onto surfaces the radioisotope 99m-technetium was used as a tracer. The radiation from the isotope was determined on protective gloves and bench covers after preparation and administration. The mean airborne emission was 6 ng m(-3) with the closed system and 15 ng m(-3) with the traditional pump technique. The average surface spillage using the closed technique was 0.005 microL. This is significantly smaller than with the traditional technique, which resulted in an average spillage of 64 microL. Our results also show that the dominant part of the leakage is surface spillage. Inexperienced nurses could also adequately handle the closed system. 相似文献
864.
865.
Violante N Petrucci F Senofonte O Cristaudo A Di Gregorio M Forte G Alimonti A 《Journal of environmental monitoring : JEM》2005,7(5):463-468
Airborne particulate matter was collected and biomonitoring of workers was performed by sampling blood, urine and hair of 84 exposed subjects, 17 occasionally exposed employees, 21 controls from administrative offices and 25 unexposed people (external controls). Determination of Pd was performed using Quadrupole and High Resolution Inductively Coupled Plasma Mass Spectrometry. The Production of Catalysts Department and the Refining Service presented the highest levels of Pd in airborne matter collected by means of an area sampler. The highest level of soluble Pd (1.66 microg m(-3)) was found in the Production of Catalysts Department. The highest concentration of Pd in airborne matter, collected by means of personal devices (7.90 microg m(-3)) was found in the Refining Service. Hair showed a clear distribution pattern among departments, with values ranging from 0.60 to 5.54 microg g(-1). Administrative workers presented blood levels of Pd between 2 and 500 times higher than external controls. Only urine levels correlated with the measurements of airborne Pd collected with personal devices. A very strong association between airborne Pd collected by personal devices and Pd levels in hair (r(2)= 0.569, with p< or = 0.01) and urine (r(2)= 0.684, with p< or = 0.01) was found. On the basis of these findings: (i) blood results appear to be an unsuitable biological marker for occupational exposure to Pd; (ii) urine could be considered as a satisfactorily responsive bio-marker for occupational monitoring; and (iii) hair cannot be considered a good index of time-related exposure. 相似文献
866.
Björklund Blom L Morrison GM Segura Roux M Mills G Greenwood R 《Journal of environmental monitoring : JEM》2003,5(3):404-409
A cellulose acetate membrane, positioned in a passive sampler system, was coated with the perfluorinated polymer Nafion. Aqueous metal transport through the membrane and the Nafion film was investigated. The Nafion-coated membrane prevents the transport of metals bound to natural organic material to the receiving phase in the passive sampler, while copper associated with small synthetic ligands pass through the Nafion film. Increasing thickness of the Nafion film decreases the metal uptake rate to the receiving phase in the passive sampler and increases the response time. A decreased response time for the passive sampler would provide a better estimation of rapid changes in concentration, particularly for dynamic aquatic systems such as urban runoff. Limited biofouling protection with the Nafion coating was demonstrated by growth inhibition of natural periphyton communities on glass surfaces. 相似文献
867.
This paper deals with how the natural behavior of animals kept for production can be integrated when planning new housing systems or making changes to existing housing systems. Natural behavior can be defined as the repertoire of different behaviors animals show when kept in environments where they can carry out behaviors created in the evolutionary process. Motivation and innate behaviors are important aspects of natural behavior, and hindering them may lead to abnormal behavior and stress. One should first get a basic knowledge about the species-specific behavior in the wild or a seminatural environment. Thereafter, key stimuli and key features for normal behavior should be worked out, where after a reduction in space, development of a pen, scientific testing, modification, and finally testing the function in a larger scale should be carried out. Examples of housing of calves during the milk period and housing of sows around farrowing are given. 相似文献
868.
Effects of arsenic on concentration and distribution of nutrients in the fronds of the arsenic hyperaccumulator Pteris vittata L 总被引:7,自引:0,他引:7
Pteris vittata was the first terrestrial plant known to hyperaccumulate arsenic (As). However, it is unclear how As hyperaccumulation influences nutrient uptake by this plant. P. vittata fern was grown in soil spiked with 0-500 mg As kg(-1) in the greenhouse for 24 weeks. The concentrations of essential macro- (P, K, Ca, and Mg) and micro- (Fe, Mn, Cu, Zn, B and Mo) elements in the fronds of different age were examined. Both macro- and micronutrients in the fronds were found to be within the normal concentration ranges for non-hyperaccumulators. However, As hyperaccumulation did influence the elemental distribution among fronds of different age of P. vittata. Arsenic-induced P and K enhancements in the fronds contributed to the As-induced growth stimulation at low As levels. The frond P/As molar ratios of 1.0 can be used as the threshold value for normal growth of P. vittata. Potassium may function as a counter-cation for As in the fronds as shown by the As-induced K increases in the fronds. The present findings not only demonstrate that P. vittata has the ability to maintain adequate concentrations of essential nutrients while hyperaccumulating As from the soil, but also have implications for soil management (fertilization in particular) of P. vittata in As phytoextraction practice. 相似文献
869.
卷烟包装材料及滤嘴的生物降解性能研究 总被引:1,自引:0,他引:1
本研究以目前几种常见的卷烟包装用商标纸、卡纸、铝箔内衬纸、透明塑料薄膜以及卷烟滤嘴为实验材料,采用ATSMD-5338标准方法,进行了为期25天实验。结果表明商标纸、铝箔纸内衬纸和卡纸的生物降解性能比较好,而滤嘴和透明塑料薄膜的生物降解性能比较差。今后研究开发可降解卷烟包装材料应该把重点放在滤嘴和透明塑料薄膜上面。 相似文献
870.
Observations on individually marked fallow deer (Dama dama) in central Italy were performed over 2 years in order to analyse time budgets of four age and sex classes. The aim was to test whether feeding activity was influenced by mating activity, forage quality or physiological constraints during the rut. Only adult males (bucks) completely ceased feeding during the rutting season, well before the actual start of mating behaviour and concurrently with the phenomenon of scent-urination, and spending most of their daily time completely inactive. All other age and sex classes were unaffected in their feeding behaviour by the rutting season. Indeed, females and young males showed a marked increase in grazing in response to an improvement in forage quality from summer to autumn. These results seem to confirm the hypothesis that hypophagia, displayed only by bucks, may be of no adaptive value in itself. On the other hand, it may be a by-product of other physiological processes occurring during the rut, inducing scent-urination, which plays an important role in intraspecific recognition and sexual attraction. 相似文献