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1.
222Rn concentrations in the air in Nerja Cave (Spain) have been measured over 4 yr and at four sampling points. Concentrations average 168 Bq m-3 in the spring–summer when the temperature lapse rate provides a stable cave atmosphere. In the autumn–winter, the radon levels decrease to 48 Bq m-3. 222Rn flux has also been measured for soils in the cave, with an average value of 34 × 10-3 Bq m-2 s-1. The average natural flow rate in the spring–summer is about 0.70 m3 s-1 and the autumn–winter is approximately 3.6 m3 s-1 determined over 1992–1995. The radiation exposure levels for workers and tourists represent only a low percentage of the exposure guides for the general population.  相似文献   

2.
The fluctuation during the last 100 yr of the eolian dust (Kosa aerosol) originating from arid and semi-arid areas of China has been reconstructed by using the sediments from Lake Kawaguchi, central Japan with high temporal resolution. The quantification of Kosa contribution to the sediments was carried out by a new method using scanning electron microscopy-energy dispersive X-ray microanalysis (SEM-EDX) proposed by us. The correlation plot of (Na2O+K2O) contents against SiO2 was used for individual Si-rich particles having SiO2 content over 80%. The Kosa fraction of Si-rich particles in Lake Kawaguchi sediments during the last 100 yr is approximately 10–30%. The fluctuation of the Kosa fraction during the last 100 yr does not coincide with that of the total amount of Si-rich particles, because detrital components from Japanese igneous rocks control the fluctuation of the total number of Si-rich particles. The discrimination method based on single particle analysis is more effective than that of bulk analysis for the lake sediments formed by complex matrix components. We can first show a short-term (approximately 10–20 yr scale) cycle in Kosa aerosol fluctuation. Higher sedimentation rates (5–10 yr-cm) of the Lake Kawaguchi sediments and the new analytical method using SEM-EDX revealed a remarkable fluctuation pattern of Kosa aerosol, suggesting climate cycles much shorter than glacial–interglacial. Such short-term cycles may be related to sun-spots. The number of days of Kosa events during the last 30 yr, obtained by visual observation by Meteorological Agency of Japan, also supports the presence of such a short-term cycle.  相似文献   

3.
In situ measurements of nitric acid (HNO3), reactive nitrogen (NOy), nitric oxide (NO), and ozone (O3) made in the upper troposphere (UT) and lower stratosphere (LS) between 29° and 33°N latitudes during September 1999 are used to examine NOy partitioning and correlations between the measured species in these regions. The fast-response (1 s) HNO3 measurements are acquired with a new autonomous CIMS instrument. In the LS, HNO3 accounts for the majority of NOy, and the sum of HNO3 and NOx accounts for approximately 90% of NOy. In the UT, the sum of HNO3 and NOx varies between 40% and 100% of NOy. Both HNO3 and NOy are strongly positively correlated with O3, with larger correlation slopes in the UT than in the LS. In the UT at low values of the quantity (NOy–NOx–HNO3), it is uncorrelated with O3, while at higher values, a positive correlation with O3 is found. Of these two air mass types, those with higher (NOy–NOx–HNO3) mixing ratios are likely associated with the presence of peroxyacetyl nitrate (PAN) that is produced by NOx-hydrocarbon chemistry.  相似文献   

4.
Particle emissions caused by railway traffic have hardly been investigated in the past, due to their obviously minor influence on air quality compared to automotive traffic. In this study, emissions related to particle abrasion from wheels and tracks were investigated next to a busy railway line in Zürich (Switzerland), where trains run nearly exclusively with electrical locomotives. Hourly size-segregated aerosol samples (0.1–1, 1–2.5 and 2.5–10 μm) were collected with a rotating drum impactor (RDI) and subsequently analyzed by synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). In this way, hourly elemental mass concentrations were obtained for chromium, manganese, iron and copper, which are the elements most relevant for railway abrasion. Additionally, daily aerosol filters were collected at the same site as well as at a background site for subsequent analysis by gravimetry and wavelength dispersive XRF (WD-XRF). Railway related ambient air concentrations of iron and manganese were calculated for the coarse (2.5–10 μm) and fine (<2.5 μm) particle fraction by means of a Mn/Fe ratio investigation. The comparison to train type and frequency data showed that 75% and 60% of the iron and manganese mass concentrations related to cargo and passenger trains, respectively, were found in the coarse mode. The railway related iron mass concentration normalized by the train frequency ranges between 10 and 100 ng m−3 h iron in 10 m distance to the tracks, depending on train type. It is estimated that the personal exposure next to a busy railway line above ground is more than a magnitude lower than inside a subway station.  相似文献   

5.
A biofilter using granular activated carbon with immobilized Paracoccus sp. CP2 was applied to the elimination of 10–250 ppm of trimethylamine (TMA), dimethylamine (DMA), and methylamine (MA). The results indicated that the system effectively treated MA (>93%), DMA (>90%), and TMA (>85%) under high loading conditions, and the maximum degradation rates were 1.4, 1.2, and 0.9 g-N kg−1 GAC d−1. Among the three different amines treated, TMA was the most difficult to degrade and resulted in ammonia accumulation. Further study on TMA removal showed that the optimal pH was near neutral (6.0–8.0). The supply of high glucose (>0.1%) inhibited TMA removal, maybe due to substrate competition. However, complete TMA degradation was achieved under the co-immobilization of Paracoccus sp. CP2 and Arthrobacter sp. CP1 (96%). Metabolite analysis results demonstrated that the metabolite concentrations decreased by a relatively small 27% while the metabolite apparently increased by heterotrophic nitrification of Arthrobacter sp. CP1 in the co-immobilization biofilter.  相似文献   

6.
Equations are derived from the Gaussian plume mode! and prescribe the critical downwind distance, wind speed, and plume rise values that result in maximum ground-level concentrations (MGLC) under downwash conditions. The derivations apply to bent-over plumes and encompass the Schulman-Scire and Huber-Snyder building downwash treatments.  相似文献   

7.
《Chemosphere》2011,82(11):1416-1422
To investigate the occurrence and fate of ritalinic acid – the main human metabolite of the psychostimulant drug methylphenidate – in the aquatic environment, a HPLC–electrospray–MS/MS method for the quantification of ritalinic acid in wastewater, surface water and bank filtrate was developed. Carbamazepine known as very stable in the aquatic environment was analyzed as anthropogenic marker in parallel. Furthermore, the removal of ritalinic acid was studied in a sewage treatment plant using an activated sludge system during a field study and in lab-scale plants. In good agreement between lab-scale and field studies a low removal rate of 13% and 23%, respectively, was determined. As a consequence, the concentration of ritalinic acid in the wastewater effluents were in the range of <50–170 ng L−1 which corresponds to a mean specific load per capita of 17.7 μg d−1.Ritalinic acid has further been detected in German rivers at concentrations of 4–23 ng L−1 and in bank filtrate samples in 100–850 m distance from the river up to 5 ng L−1 demonstrating the widespread occurrence of this stable metabolite in the aquatic environment. A comparison to available sales data shows that a significant amount of methylphenidate applied can be found in waters as ritalinic acid.  相似文献   

8.
Significant accumulation of heavy metals in soils and flora exists around the abandoned Barbadalhos Pb mine in Central Portugal. Soil and plant samples [49 species] were collected from two line transects, LT 1 and LT 2, in the mineralized and non-mineralized area, respectively to gain a comprehensive picture of heavy metals in soils and flora to assess its potential for phytoremediation. Phytosociological inventories of the vegetation were made using the Braun-Blanquet cover-abundance scale. Metal concentrations in soil ranged from (in mg kg?1): 98–9330 [Pb], 110–517 [Zn], 7.1–50 [Co], 69–123 [Cr], 31–193 [Cu], 33 400–98 500 [Fe], 7.7–51 [Ni], 0.95–13 [Ag], 2.8–208 [As], and 71–2220 [Mn] along LT 1; and 24–93 [Pb], 30–162 [Zn], 3.7–34 [Co], 61–196 [Cr], 21–46 [Cu], 24 100–59 400 [Fe], 17–87 [Ni], 0.71–1.9 [Ag], 4.3–12 [As], and 44–1800 [Mn] along LT 2. Plant metal content ranged from (in mg kg?1): 1.11–548 [Pb], 7.06–1020 [Zn], 0.08–2.09 [Co], 0.09–2.03 [Cr], 2.63–38.5 [Cu], 10.4–4450 [Fe], 0.38–8.9 [Ni], and 0.03–1.9 [Ag] along LT 1; and 0.94–11.58 [Pb], 2.83–96.5 [Zn], 0.12–1.44 [Co], 0.21–1.49 [Cr], 1.61–22.7 [Cu], 4.6–2050 [Fe], 0.51–4.81 [Ni], and 0.02–0.31 [Ag] along LT 2. Plants with highest uptake of metals were: Cistus salvifolius (548 mg Pb kg?1), Digitalis purpurea (1017 mg Zn kg?1 and 4450 mg Fe kg?1). Mentha suavolens and Ruscus ulmifolius were seen to hyperaccumulate Ag (1.9 and 1 mg Ag kg?1, respectively). More metals and higher concentrations were traced in plants from LT 1, especially for Pb and Zn.  相似文献   

9.
LAS对土壤中多环芳烃吸附行为的影响   总被引:2,自引:0,他引:2  
研究了阴离子表面活性剂十二烷基苯磺酸钠(LAS)对PAHs在土壤中吸附行为的影响.结果表明,LAS改变了PAHs在土水体系中的吸附/解吸平衡,吸附态LAS可提高土壤对PAHs的吸附,而溶解态LAS则增加了PAHs的表观溶解度,这2种作用的综合结果改变了PAHs在土水体系中的吸附系数.因此,文中用表观吸附系数来描述PAHs在土壤-水-LAS体系中的综合吸附行为.  相似文献   

10.
11.
This is the second part of a two-part discussion, in which we will provide an overview of the use of GIS and GPS in environmental analysis and enforcement. Geographic Information Systems (GIS) describes a system which manages, analyses and displays geographic information. Environmental applications include analysis of source, extent and transport of contaminants, nonpoint runoff modeling, flood control, and emergency response support. The ability to examine spatial relationships between environmental observations and other mapped and historical information, and to communicate these relationships to others, makes GIS valuable in environmental forensics. The US Environmental Protection Agency currently requires the inclusion of locational information with all other environmental data that is collected. Geographic Information Systems is a complex tool that requires careful planning and design to be successfully implemented. Choices in hardware, software and data development must be based on evaluation of project objectives, analytical requirements, data availability and data development considerations. Data sets must be evaluated and documented with metadata. The Global Positioning System (GPS) is a satellite-based system which provides highly accurate, three-dimensional position information anywhere on the earth’s surface. Using portable radio receivers, field analysts can easily record the positions of spill sites, sampling locations and other environmental features. Spatial accuracy of GPS ranges from 20–30 m (single receiver) to 1–5 m (differential GPS) for navigation-grade instruments, and down to millimeter level accuracy for geodetic units. Global Position Systems can be used not only to capture spatial information into a GIS system, but also to evaluate and quantify the spatial accuracy of existing digital map data, and to provide control points for existing aerial photographs and other remotely-sensed data.  相似文献   

12.
Neutral volatile and semi-volatile polyfluorinated organic compounds (PFC) and ionic perfluorinated compounds were determined in air samples collected at two sites in the vicinity of Hamburg, Germany, and onboard the German research vessel Atair during a cruise in the German Bight, North Sea, in early November 2007. PUF/XAD-2/PUF cartridges and glass fiber filters as sampling media were applied to collect several fluorotelomer alcohols (FTOH), fluorotelomer acrylates (FTA), perfluoroalkyl sulfonamides (FASA), and perfluoroalkyl sulfonamido ethanols (FASE) in the gas- and particle-phase as well as a set of perfluorinated carboxylates (PFCA) and sulfonates (PFSA) in the particle-phase. This study presents the distribution of PFC in ambient air of the German North Sea and in the vicinity of Hamburg for the first time. Average total PFC concentrations in and around Hamburg (180 pg m?3) were higher than those observed in the German Bight (80 pg m?3). In the German Bight, minimum–maximum gas-phase concentrations of 17–82 pg m?3 for ΣFTOH, 2.6–10 pg m?3 for ΣFTA, 10–15 pg m?3 for ΣFASA, and 2–4.4 pg m?3 for ΣFASE were determined. In the vicinity of Hamburg, minimum–maximum gas-phase concentrations of 32–204 pg m?3 for ΣFTOH, 3–26 pg m?3 for ΣFTA, 3–18 pg m?3 for ΣFASA, and 2–15 pg m?3 for ΣFASE were detected. Concentrations of perfluorinated acids were in the range of 1–11 pg m?3. FTOH clearly dominated the substance spectrum; 8:2 FTOH occurred in maximum proportions. Air mass back trajectories, cluster, and correlation analyses revealed that the air mass origin and thus medium to long range atmospheric transport was the governing parameter for the amount of PFC in ambient air. Southwesterly located source regions seemed to be responsible for elevated PFC concentrations, local sources appeared to be of minor importance.  相似文献   

13.
Abstract

Composts improve organic carbon content and nutrients of calcareous soils but the accumulation and distribution of phosphorus and heavy metals among various fractions in soil may vary under the south Florida conditions. The accumulation of P, Cd, Ni, and Pb with depth and the distribution of water soluble, exchangeable, carbonate, Fe–Mn oxides, organic and residual forms of each element were investigated in soils amended with municipal solid waste (MSW) compost, co-compost and biosolids compost and inorganic fertilizer (as control). Total concentrations of P, Cd, Ni, and Pb were higher in the 0–22 cm soil layers and decreased considerably in the rock layers. These elements were in the decreasing order of P ? Pb > Ni > Cd. Amounts of water soluble and exchangeable forms of P, Cd, Ni and Pb were negligible at 0–22 cm soil depths except for Cd in the 10–22 cm depth. Amending calcareous soil with either organic or inorganic amendments rendered phosphorus, nickle and lead in the residual form followed by Fe–Mn oxides form in the 0–10 and 10–22 cm soil layers. Cadmium was predominantly in the Fe–Mn oxides fraction followed by the residual and carbonate forms in both soil layers. A significant positive correlation was found between various organic carbon fractions and organic forms of P, Cd and Pb in the surface soil layer. Soil amended with MSW compost had higher concentration of Cd in the organic fraction whereas, co-compost and MSW compost amended soil had higher concentrations of organic Ni fraction in the 0–10 cm soil layer.  相似文献   

14.
A study of the in vitro sensitivity of 12 isolates of Phytophthora infestans to metalaxyl, azoxystrobin, dimethomorph, cymoxanil, zoxamide and mancozeb, was conducted. The isolates derived from infected potato leaves collected at eight different localities in Serbia during 2005–2007. The widest range of EC50 values for mycelial growth of the isolates was recorded for metalaxyl. They varied from 0.3 to 3.9 μg mL?1 and were higher than those expected in a susceptible population of P. infestans. The EC50 values of the isolates were 0.16–0.30 μg mL?1 for dimethomorph, 0.27–0.57 μg mL?1 for cymoxanil, 0.0026–0.0049 μg mL?1 for zoxamide and 2.9–5.0 μg mL?1 for mancozeb. The results indicated that according to effective concentration (EC50) the 12 isolates of P. infestans were sensitive to azoxystrobin (0.019–0.074 μg mL?1), and intermediate resistant to metalaxyl, dimethomorph and cymoxanil. According to resistance factor, all P. infestans isolates were sensitive to dimethomorph, cymoxanil, mancozeb and zoxamide, 58.3% of isolates were sensitive to azoxystrobin and 50% to metalaxyl. Gout's scale indicated that 41.7% isolates were moderately sensitive to azoxystrobin and 50% to metalaxyl.  相似文献   

15.
It is well known that mainstream (MS) and sidestream (SS) cigarette smoke contains a vast number of chemical substances. Previous studies have emphasized SS smoke rather than MS smoke to which smokers are exposed, and most have used chamber tests that have several disadvantages such as wall losses. Emissions from standard research cigarettes have been measured, but relatively few constituents have been reported, and only the 1R4F (low nicotine) cigarette type has been tested. This study provides a comprehensive characterization of total, MS and SS smoke emissions for the 1R5F (ultra low nicotine), 2R4F (low nicotine), and 1R3F (standard nicotine) research cigarettes research cigarettes, including emission factors for a number of toxic compounds (e.g., benzene) and tobacco smoke tracers (e.g., 2,5-dimethyl furan). Emissions of volatile organic compounds (VOCs) and particulate matter (PM) are quantified using a dynamic dilution emission measurement system that is shown to produce accurate, rapid and reproducible results for over 30 VOCs and PM. SS and MS emissions were accurately apportioned based on a mass balance of total emissions. As expected, SS emissions greatly exceeded MS emissions. The ultra low nicotine cigarette had lower emissions of most VOCs compared to low and standard nicotine cigarettes, which had similar emissions. Across the three types of cigarettes, emissions of benzene (296–535 μg cig−1), toluene (541–1003 μg cig−1), styrene (90–162 μg cig−1), 2-dimethyl furan (71–244 μg cig−1), naphthalene (15–18 μg cig−1) and other VOCs were generally comparable to or somewhat higher than literature estimates using chamber tests.  相似文献   

16.
Ohne Zusammenfassung Univ. Prof. Dr. GerdPeschke (†22. August 2001) gewidmet, der die Geschikke des Internationalen Hochschulinstituts Zittau in seiner Aufbauphase seit 1993 wesentlich mitgepr?gt hat und bis vor kurzem den Lehrstuhl §Umweltsystemwissenschaften’ am IHI Zittau mit Leben füllte. Ihm haben Diskussionen über die Zukunft der Umweltwissenschaften immer viel Freude bereitet. Danke, lieber Freund!  相似文献   

17.
Abstract

Odorous gases associated with livestock operations are complex mixtures of hundreds if not thousands of compounds. Research is needed to know how best to sample and analyze these compounds. The main objective of this research was to compare recoveries of a standard gas mixture of 11 odorous compounds from the Carboxen/PDMS 75–μm solid–phase microextraction fibers, polyvinyl fluo–ride (PVF; Tedlar), fluorinated ethylene propylene copolymer (FEP; Teflon), foil, and polyethylene terephthalate (PET; Melinex) air sampling bags, sorbent 2,b–diphenylene–oxide polymer resin (Tenax TA) tubes, and standard 6–L Stabilizer sampling canisters after sample storage for 0.5, 24, and 120 (for sorbent tubes only) hrs at room temperature. The standard gas mixture consisted of 7 volatile fatty acids (VFAs) from acetic to hexanoic, and 4 semivolatile organic compounds including p–cresol, indole, 4–ethylphenol, and 2'–aminoacetophenone with concentrations ranging from 5.1 ppb for indole to 1270 ppb for acetic acid. On average, SPME had the highest mean recovery for all 11 gases of 106.2%, and 98.3% for 0.5– and 24–hr sample storage time, respectively. This was followed by the Tenax TA sorbent tubes (94.8% and 88.3%) for 24 and 120 hr, respectively; PET bags (71.7% and 47.2%), FEP bags (75.4% and 39.4%), commercial Tedlar bags (67.6% and 22.7%), in–house–made Tedlar bags (47.3% and 37.4%), foil bags (16.4% and 4.3%), and canisters (4.2% and 0.5%), for 0.5 and 24 hr, respectively. VFAs had higher recoveries than semivolatile organic compounds for all of the bags and canisters. New FEP bags and new foil bags had the lowest and the highest amounts of chemical impurities, respectively. New commercial Tedlar bags had measurable concentrations of N,N–dimethyl acetamide and phenol. Foil bags had measurable concentrations of acetic, propionic, butyric, valeric, and hexanoic acids.  相似文献   

18.
Abstract

Teratogenicity studies were conducted in rats treated orally from days 6–15 of gestation with single daily doses of 400–1600 mg/kg of maleic hydrazide, 300–1000 mg/kg daminozide, 125–500 mg/kg ethoxyquin or thiabendazole, or 25–100 mg/kg naled. Dams were killed on the 22nd day of gestation, and fetuses were evaluated by routine teratologic methods. No adverse effect was related to any treatment other than an increased incidence of anomalous fetuses at the highest dose (500 mg/kg) of thiabendazole.  相似文献   

19.
The effect of coexisting pesticide on adsorption/desorption and mobility of another one was investigated with carbendazim (CBD), imidacloprid (IDP), and atrazine (ATR). The data indicated that adsorption of CBD, ATR, and IDP on the tested soil was fitted well by Freundlich equation and increased with an order of IDP < ATR ? CBD. Adsorption of a pesticide was decreased by the coexistence of another one through their competitive adsorption. The presence of coexisting solute of the more adsorbability played a more important role than that of the lesser adsorbability. The adsorption of IDP and ATR was easier to be affected by 28.9–52.0 % and 31.1–60.7 % with the addition of CBD, while that of CBD was much less influenced by 3.4–18.1 % and 6.9–31.8 % with the presence of ATR and IDP, respectively. An adsorbability-related enhancement in desorption of the three pesticides by the co-adsorbed solute was also observed. As a result of competitive adsorption/desorption, the mobility of the pesticides estimated from soil thin-layer chromatography was altered. The results clearly illustrated that adsorbability and concentration-related alteration in adsorption/desorption and mobility will be caused by the coexistence of pesticides.  相似文献   

20.
Abstract

The stability of dieldrin, aldrin, lindane, chlorpyrifos and prothiofos was determined in distilled water and in roof water from either galvanised or concrete tanks. Samples were stored in the dark at 23°C. Dieldrin and lindane were stable for the 36 week period. Aldrin dissipated rapidly with a half‐life of 4–5 weeks, with no dieldrin being formed. Chlorpyrifos and prothiofos also broke down, with half‐lives ranging 12–18 weeks and 11–14 weeks respectively. No significant effect of water type was found. For the purpose of domestic usage, an activated carbon filter would be essential otherwise all contaminated water would have to be disposed of safely.  相似文献   

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