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381.
Noise pollution is a common health problem for developing countries. Especially highways and airports lead to noise pollution in different levels and in many frequencies. In this study, we focused on the effect of noise pollution in airports. This work aimed measurements of noise pollution levels in Van Ferit Melen (VFM) airport and effect of noise pollution over the immunoglobulin A, G, and M changes among VFM airport workers in Turkey. It was seen that apron and terminal workers were exposed to high noise (>80 dB(A)) without any protective precautions. Noise-induced temporary threshold shifts and noise-induced permanent threshold shifts were detected between the apron workers (p?<?0.001) and terminal workers (p?<?0.005). IgA values of apron terminal and control group workers were approximately the same in the morning and increased in a linear manner during the day. This increase was statistically significant (p?<?0.001). IgG and IgM values of apron, terminal, and control group workers were approximately same in the morning. Apron and terminal workers IgG and IgM levels were increased until noon and then decreased until evening as compare to control group, but these changes were not statically significant (p?>?0.05). These findings suggested that the noise pollution in the VFM airport could lead to hearing loss and changes in blood serum immunoglobulin levels of airport workers. Blood serum immunoglobulin changes might be due to vibrational effects of noise pollution. Airport workers should apply protective precautions against effect of noise pollution in the VFM airport.  相似文献   
382.
A combination of archival, subjective, and observational field data collection methods were used to investigate the relationship between biomechanical and postural stresses, and the resulting physical strain experienced by industrial workers of a packaging plant. Assessment of physical strain was based on the number and incidence rate of Occupational Safety and Health Administration (OSHA)-reportable injuries that were recorded over a period of 27 months, and based on the self-reported ratings of perceived body discomfort. Both the biomechanical and postural stresses correlated with the musculoskeletal injury rate. The results illustrate the usefulness of postural and biomechanical analyses for assessing the risk of injury in industry.  相似文献   
383.
Government priorities on provincial Nutrient Management Planning (NMP) programs include improving the program effectiveness for environmental quality protection, and promoting more widespread adoption. Understanding the effect of NMP on both crop yield and key water-quality parameters in agricultural watersheds requires a comprehensive evaluation that takes into consideration important NMP attributes and location-specific farming conditions. This study applied the Soil and Water Assessment Tool (SWAT) to investigate the effects of crop and rotation sequence, tillage type, and nutrient N application rate on crop yield and the associated groundwater ${\text{NO}_{3}}^{ - } {\text{-N }}$ leaching and sediment loss. The SWAT model was applied to the Thomas Brook Watershed, located in the most intensively managed agricultural region of Nova Scotia, Canada. Cropping systems evaluated included seven fertilizer application rates and two tillage systems (i.e., conventional tillage and no-till). The analysis reflected cropping systems commonly managed by farmers in the Annapolis Valley region, including grain corn-based and potato-based cropping systems, and a vegetable-horticulture system. ANOVA models were developed and used to assess the effects of crop management choices on crop yield and two water-quality parameters (i.e., ${\text{NO}_{3}}^{ - } {\text{-N }}$ leaching and sediment loading). Results suggest that existing recommended N-fertilizer rate can be reduced by 10–25 %, for grain crop production, to significantly lower ${\text{NO}_{3}}^{ - } {\text{-N }}$ leaching (P > 0.05) while optimizing the crop yield. The analysis identified the nutrient N rates in combination with specific crops and rotation systems that can be used to manage ${\text{NO}_{3}}^{ - } {\text{-N }}$ leaching while balancing impacts on crop yields within the watershed.  相似文献   
384.
During April 1980, water samples were collected from 12 sites in the Shatt al-Arab River and its estuary in the northwest region of the Arabian Gulf. The samples were extracted and the concentration of petroleum hydrocarbons were determined spectrofluorometrically, in order to provide information on the background values of oil generally present in these waters. Total hydrocarbon concentrations of these samples ranged from 2.7 to 86.7 μgL?1 expressed in terms of Kuwait crude oil equivalents. The highest concentrations were found at sites in the Shatt al-Arab River that are near port areas.  相似文献   
385.
386.
Groundwater contamination due to pesticide applications on agricultural lands is of great environmental concern. The mathematical models help to understand the mechanism of pesticide leaching in soils towards groundwater. We developed a user-friendly model called ArcPRZM-3 by integrating widely used Pesticide Root Zone Model version 3 (PRZM-3) using Visual Basic and Geographic Information System (GIS) based Avenue programming. ArcPRZM-3 could be used to simulate pesticide leaching towards groundwater with user-friendly input interfaces coupled with databases of crops, soils and pesticides. The outputs from ArcPRZM-3 could be visualized in user-friendly formats of tables, charts and maps. In this study we evaluated ArcPRZM-3 model by simulating bentazon leaching in soil towards groundwater. ArcPRZM-3 was applied to 37 sites in Woodru County, Arkansas, USA to observe the daily average dissolved bentazon concentration for soybean, sorghum and rice at a depth of 1.8 m for a period of two years. Nineteen ranks of bentazon leaching potential were obtained using ArcPRZM-3 for all sites having di erent soil and crop combinations. ArcPRZM-3 simulation results for bentazon were compatible with the field monitored data in term of relative ranking and trend, although some uncertainties exist. This study indicated that macropore flow mechanism would be important in analyzing the e ect of irrigation on groundwater contamination due to pesticides. Overall, ArcPRZM-3 could be used to simulate pesticide leaching towards groundwater more e ciently and e ectively as compared to PRZM-3.  相似文献   
387.
With the increasing demand for fossil based energy and implementation of progressively strict environmental pollution control standards, treatment of a large amount of co-produced waters (CPWs) from fossil based energy production has become increasingly important. Removal of bicarbonate with H2SO4 has been recently studied as a simple and cost-e ective method to decrease the alkalinity of CPWs. The present work investigates the kinetics of the reaction between H2SO4 and NaHCO3, which could provide the base for scaling-up the CPW treatment technology. Based on the measured quantity change of the CO2 gas generated from the reaction between H2SO4 and NaHCO3 with time under specified initial reaction conditions, the reaction orders with respect to H2SO4 and NaHCO3 were determined. Experiments were also conducted within the temperature of 15–30°C to find various global rate coe cients of the reaction to calculate the activation energy and the pre-exponential factor of the empirical Arrhenius form of the bicarbonate removal reaction, which are 197.7 kJ/mol and 3.13 1034 (mol??3:7 L3:7 sec??1), respectively.  相似文献   
388.
Saudi Arabia has experienced frequent occurrences of biological disasters due to a wide range of generator factors, including natural disasters and epidemics. A national survey (n=1,164) was conducted across 13 regions of Saudi Arabia to examine public perceptions to the risk of a biological disaster. The primary results reveal: (a) a degree of knowledge about biological threats such as SARS and H5N1 flu, despite the lack of individual experience with disasters; (b) age, gender, education and faith are positively related to the perception of biological risk; and (c) a number of important community resilience factors exist, including faith, education and willingness. This study concludes that the development of adapted resilience strategies in disaster management can be achieved through public education and training involving cooperation with official organisations and religious authorities in the country to increase public awareness, knowledge and skills in mitigating biological threats.  相似文献   
389.
Yellow River, is designated as “the cradle of Chinese civilization” and played a key role not only in the country’s economic development but also in the historic and cultural identity of the Chinese people. With the rapid economic development and population growth, water demand for industry and households has increased significantly in the Yellow River basin; this has caused an increasing gap between water supply and demand. Competing water demands triggered conflicts between disparate water users on different scales such as the rich and the poor, or between different sectors and regions, such as domestic and agriculture, agriculture and industry, upstream and downstream, rural and urban areas, etc. Ensuring equity in water supply for conflicting water users is one of the major challenges that facing water managers and in particular water management in the Yellow River basin. In this paper, a method has been developed to calculate the Gini coefficient of water use as an indicator to measure the equality in domestic water supply. A dual domestic water use structure model is employed for this purpose. The developed method is subsequently applied to assess the equality in domestic water supply in the Yellow River. Data of population growth, domestic water use and economic development over the time period 1999-2006 are used to calculate the Gini coefficient of water use over the same length of period. The result shows a decreasing trend in Gini coefficient of domestic water use in the Yellow River basin after 2001 which means domestic water use is becoming more and more equitable in the basin. The study justifies that the Gini coefficient of water use can be used and recommended as a useful tool for the water management especially in the context of global change.  相似文献   
390.
nSiO_2纳米颗粒是一种广泛应用的工程纳米材料,为增加其对水溶液中Cd~(2+)的吸附性能,采用接枝改性的方法制备出乙二胺四乙酸(EDTA)改性nSiO_2纳米颗粒(EDTA-nSiO_2),并用透射电镜、氮气吸附-解吸、红外光谱和差热分析等手段对其进行了结构表征,同时以其为吸附剂,通过批处理实验法探讨了体系pH、吸附时间、温度、离子强度等因素对Cd~(2+)吸附的影响,并结合X射线能谱(XPS)分析对其吸附机制进行了分析.结果表明,以EDTA为改性剂,可以成功制备出稳定性良好的EDTA-nSiO_2纳米颗粒,其对Cd~(2+)的吸附受体系p H控制;nSiO_2对Cd~(2+)的吸附量较小,EDTA改性可增加nSiO_2对Cd~(2+)的吸附作用,随着p H的升高,Cd~(2+)的吸附效果逐渐增强,在p H大于4.0后逐渐趋于稳定.EDTA-nSiO_2对Cd~(2+)的吸附速率较快,可在1 h内达到吸附平衡.EDTA-nSiO_2对Cd~(2+)的吸附为吸热的自发过程,吸附等温线可用Langmuir模型描述.NaCl浓度增加会导致Cd~(2+)的吸附量下降,当体系Na Cl浓度从0增加到100 mmol·L~(-1),Cd~(2+)的最大吸附量从0.433 mmol·g-1降低至0.294mmol·g-1.0.1 mol·L~(-1)HCl是较为合适的吸附剂再生液,Cd~(2+)洗脱率约94.36%.结合pH、温度、离子强度、再生和XPS分析结果,可以推测出EDTA-nSiO_2对Cd~(2+)的吸附是包含有简单的物理吸附和离子交换过程,并以化学络合为主的吸附过程.EDTA-nSiO_2是一种对水体Cd~(2+)具有较好吸附能力的工程纳米材料吸附剂.  相似文献   
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