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531.
Sun HF Takata A Hata N Kasahara I Taguchi S 《Journal of environmental monitoring : JEM》2003,5(6):891-895
The degradation, sorption, transportation and material balance of cationic surfactants discharged from domestic waste into river water was studied. Ion-pair solid-phase extraction behavior showed that the sorption of cationic surfactants as an ion-pair with anionic surfactant onto river sediment was so strong that little cationic surfactant was found in the bulk water. Cationic surfactant was found in river sediment at more than 500 times higher concentration than that in the bulk water. The degradation of the cationic surfactant was very slow in river water and much slower in the sediment. A material balance of cationic surfactant was estimated for a river running through Toyama City by measuring the flow rate and the concentration of cationic surfactant in the water at several points. It was found that more than 30% of cationic surfactant introduced to the river was lost during the river running through ca. 3 km in 3 h. This reduction probably comes from a quick transfer of the cationic surfactant from river water to sediment and water weed by means of adsorption or precipitation with suspending solids. 相似文献
532.
Sandanger TM Brustad M Odland JO Doudarev AA Miretsky GI Chaschin V Burkow IC Lund E 《Journal of environmental monitoring : JEM》2003,5(4):689-696
Some of the people living in the Chukotka Peninsula of Russia depend heavily on marine mammals, but little is known of the exact dietary patterns and plasma levels of POPs among these populations. In this study, POPs levels in plasma from 50 participants from the isolated community of Uelen (Bering Strait) were determined and related to dietary information obtained through a food frequency questionnaire. The intake of marine mammals was high and the combined intake of blubber from walrus, seal and whale was a significant predictor (p < 0.01) of plasma concentrations of sum PCBs and borderline for sum CDs (p = 0.02) and sum DDTs (p = 0.04). There was a significant gender difference in the levels of POPs, and among women there was a significant increase with age. Extensive breastfeeding and lower blubber intake among women could be possible explanations for this gender difference. Despite the high intake of blubber the plasma levels of PCBs and DDTs were lower than some of those reported for the East Coast of Greenland. The geometric mean values for sum PCBs (17 congeners) and sum DDTs were 1316 ng g(-1) lipids and 563 ng g(-1) lipids, respectively. PCB 163, which partly co-eluted with PCB 138, was found in high concentrations (40% of PCB 138). This raises questions regarding the validity of using PCB 138 and PCB 153 to calculate the level of Arochlor 1260. The geometric mean of sum CDs was 518 ng g(-1) lipids. Concentrations of beta-HCH (geometric mean; 410 ng g(-1) lipids) were higher than observed for other native populations depending on marine mammals. Transportation of beta-HCH by ocean currents through the Bering Strait into the Arctic Ocean or regional point sources might explain these elevated levels. 相似文献
533.
Peter A. Beedlow Don S. Daly Michael E. Thiede 《Environmental monitoring and assessment》1986,6(3):277-282
An electrical device capable of continuously measuring micronsized changes in stem diameter of woody and herbaceous plants is described. Fumigation of sunflowers with automotive exhaust was used to test the ability of the device to detect short-term plant responses. 相似文献
534.
Eolian (wind blown) sand constitutes a very serious problem to development in sandy desert lands and causes equally serious problems in lands that are undergoing desertification. In this paper, eolian sand movement due to bulk movement such as sand dune and ripple movement, sand drift by saltation, and sand storms by strong winds are discussed. Associated problems such as eolian sand encroachment on highways, farms, communities and industrial complexes are also discussed and workable solutions are offered. Solutions include chemical stabilization of the surface grains, fences to trap the blown sand and vegetation to prevent soil deflation. Vegetation is emphasized and recommended as the ultimate viable solution to combat desertification and eolian sand problems. 相似文献
535.
CO concentrations were measured in five kindergartens, one children's hospital and two homes for aged, practically without indoor sources, all situated in the city centre, for ten random days in winter and ten in summer. The indoor CO concentrations were the result of the distance from and the traffic density in the nearest street, of general pollution level, seasonal differences, day-to-day variations and daily cycle of air pollution, the vicinity of traffic having a dominant influence. Therefore location of institutions for sensitive population groups in old city centres within a block of houses seems to be a suitable solution as far as exposure to CO is concerned.Revised version of a paper presented as poster at the VIth World Congress on Air Quality, Paris 1983. 相似文献
536.
Distribution of heavy metals in water and sediments of selected sites of Yamuna river (India) 总被引:2,自引:0,他引:2
Mohammad Ajmal Mujahid A. Khan Azhar A. Nomani 《Environmental monitoring and assessment》1985,5(2):205-214
The concentration of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn metals in water and sediments of Yamuna river were determined by atomic absorption spectrophotometry in the year 1981. The data showed that there was considerable variation in the concentration of elements from one sampling station to the other which may be due to the variation in the quality of industrial and sewage wasters being added to the river at different sampling stations. The sediment samples collected from different sampling stations were also analysed for calcium carbonate, organic matter, potassium, and phosphorus. 相似文献
537.
Extreme pollutant values are of great interest in water quality monitoring because of their frequent toxicological significance. The principal barrier to the detection of these values, however, is the cost of extensive and comprehensive monitoring. This paper demonstrates an efficient method to determine the maximum sample measurement from a finite set of sequential samples without explicitly testing them all. It is assumed that the process of sample measurement is distinct from collection and has higher costs. It is further assumed that the measurements have high positive autocorrelation.A methodology is presented based on a common industrial testing procedure referred to as composite sampling—the physical pooling or compositing of a set of sequential samples before measurement. A method known as primary first order compositing (PFOC) was found to be superior to the traditional technique of random sampling, particularly if small composite sizes are utilized.The authors are, respectively, operations research analyst, Vancouver, B. C.; Associate Professor and Chairman, Policy Analysis Division, Faculty of Commerce and Business Administration, University of British Columbia; and Associate Professor, Management Science Division, Faculty of Commerce, U.B.C. 相似文献
538.
An attempt was made to explain ambient air quality violations in the vicinity of industrial plants. Micrometeorology, diffusion calculaations, ambient readings, and plant engineering data are all taken into consideration to ascertain whether the plant is or is not the principal offender.Scrutiny of hi-vol filters using scanning electron microscopy for particle size analysis and particle chemical make-up as an assessment technique is also described.Case histories using the above analytical techniques are discussed.Presented at the 16th National Conference on Energy and the Environment, May 23, 1979 相似文献
539.
540.
Compilation of published and unpublished data shows acid precipitation to be more widespread in the Pacific coastal states than is generally recognized. Although information is scattered and discontinuous, precipitation is definitely acidic in the Los Angeles Basin and north-central california, and in the Puget Sound region in Washington. Acid rain occurrences have been observed in western and eastern Oregon, but data are inadequate for regional generalization. New stations currently being established in Washington and Oregon, largely in resposnse to the recently renewed activity of Mount St. Helens, will greatly facilitate assessment of precipitation acidity in the Northwest. 相似文献