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151.
Federal and State agencies have recently advocated risk-based analysis as a mechanism for advancing regulatory reform and safety determination in marine systems. the present investigation promotes this objective through the development of risk-based environmental planning strategies for oil spill contingency plans. This alternative approach to contingency planning departs from conventional methodology by employing quantitative risk assessment methods to identify hazardous oil spill zones and sensitive environmental areas, Ro and Re respectively. the product of this conversion is referenced on a single “Risk” layer within a Geographic Information System (GIS) framework allowing coastal managers to evaluate natural resource data with associated elements of oil spill risk. As a new tool for coastal pollution management, risk-based environmental planning strategies have shown potential for evolving more efficient oil spill contingency plans.  相似文献   
152.
Carbon tetrachloride (CCl4) is a toxic chemical that was once used in degreasers and detergents, and some remnants of the chemical may be present in the water supply. Physiologically-based pharmacokinetic (PBPK) modeling can assist in understanding resulting internal doses of CCl4 after exposure, but the pharmacokinetic parameters describing the metabolism of CCl4 are not well characterized. The goal of this study was to provide insights into how to more accurately estimate these values in rats using PBPK modeling and data from previous studies. Three different PBPK models were constructed to describe CCl4 exposure in rats via inhalation, oral ingestion, and venous injection. Each of these models was compared to data, and sensitivity analysis was performed for each model to determine whether the available data could be used to accurately determine the metabolic parameters of interest. These parameter sensitivities were so low that optimization to the available data yielded physiologically unrealistic results. Model sensitivities were analyzed for different doses and routes of exposure in order to find experimental conditions that would allow for greater identifiability of the metabolic parameters. Data were simulated from these models at optimal conditions with varying levels of noise from a normal distribution. Optimizations were then performed to confirm that the original values could be obtained. The experiments developed are left as suggestions for investigators who wish to further pursue estimating these metabolic parameters.  相似文献   
153.
This article assesses the air pollution data from two monitoring stations in Kuwait. The measurements cover major pollutants, i.e., CO, CO2, methanated and non-methanated hydrocarbons, NO x , SO2, O3, and particulate matter (PM10). The data also includes meteorological parameters, i.e., solar intensity, temperature, wind speed, and wind direction, and has been collected over a period 4 years, from 2001 to 2004. Data analysis includes the assessment of annual hourly averages and 1-h maxima. Typical pollutant concentration trends, similar to those previously reported for Kuwait and for other locations around the world, are observed except for particulate matter measurements, which have higher values because of proximity to the desert. Emissions of nitrogen oxides show a consistent increase over the years. This is caused by the increase in the number of motor vehicles and the expansion in power generation and industrial activities. The data collected is a subset of the air quality criteria, as defined by the US EPA (United States Environmental Protection Agency).  相似文献   
154.
Monitoring and modeling of the concentrations of trihalomethanes (THMs) within four water treatment plants (WTPs) and distribution lines in Fayoum City, Egypt, were studied. Sampling sites for raw and treated waters were determined by global positioning system and the Arc geographic information system software was used for mapping. THMs were monitored using 25 sampling points located at the plant exit and through the distribution lines up to the plant extremity. Results indicated that the THMs concentration varied significantly but it was very rarely higher than the allowed maximum contaminant level of 100 μg L?1. However, at the dead zones in the distribution lines, the THMs increased by about 160% compared to in-plant level. Furthermore, the level of THMs in hot months was about 1.3 times higher than in cold ones. The influence of some independent variables such as temperature, pH, ammonia concentration, total organic carbon and color were investigated by Pearson model to find their correlation with the rate of THMs formation in WTPs. The resulted R values ranged from 0.81 to 0.98. Successful application of the model to a selected region on the distribution lines has resulted in a correlation coefficient of 0.98.  相似文献   
155.
Oxidative stress and antioxidant responses of crucian carp, upon chronic exposure to endosulfan, were evaluated in vivo. The lethal concentration (LC50–96?h) was 70 μg L?1; on its basis, the fish were exposed to endosulfan at 20, 35, and 50 μg L?1 and autopsy was done on days 1, 2, 3, 4, 7, 14, 21, 28, and 35. Lipid peroxidation was induced in a concentration-dependent manner, being highest at 50 μg L?1 (3/4 LC50–96 h, sub-lethal concentration-I, SL-I) on day 4 (720% versus control), followed in its extent (490%) at 30 μg L?1 (1/2 LC50–96 h, sub-lethal concentration-II, SL-II) on day 7 and lowest (260%) at 10 μg L?1 (1/4 LC50–96 h, sub-lethal concentration-III, SL-III) on day 14. Glutathione showed a concentration- and time-dependent elevation in the initial phase, with highest level on day 4 (180%) at SL-I, but showed significant reduction in all test concentrations from day 21 of post-exposure. Superoxide dismutase was decreased significantly throughout the study, with highest reduction (63%) on day 4 at SL-I; catalase increased in all test concentrations up to day 14 but showed a significant decrease from the day 28 of post-exposure. The potential role of these parameters as indicators of pesticide pollution in aquatic systems is discussed.  相似文献   
156.
The formulation of a sound policy for environmental protection and toxic substances control requires knowledge of the presence and concentration of environmental contaminants. For this reason monitoring programs have been set up in the Netherlands for water, drinking water, and air pollution. The Netherlands system for air pollution, monitoring of the substances SO2, NOχ, CO, O3 is now fully automated. Some examples will be given to show the acquisition and management and interpretation of air pollution measurements.

Various smaller projects, supported by the Department of Health and Environmental Protection include measurement of indoor air‐contaminants, contaminants in soil and hazardous waste sites, and contaminants in biotic samples such as for instance PCB's in eels and seals and mussels. Moreover a Coordinating Committee regularly collects measurements from various sources in the Netherlands regarding pesticide residues and contaminants in food.

For cost‐effective monitoring the accuracy of the measurements must be chosen with regard to the biological effect concentration of the pollutant. The necessity of proper control measurements to establish background levels and the necessity of ring‐tests to increase interlaboratory reproducibility is discussed. In cost‐effective monitoring the minimum number of measurements, which are necessary to check the effect of environmental protection measures, must be defined through proper sampling.  相似文献   
157.
Examination of vapor above commercial sodium humate and above 10wt% aqueous humate solution by gas chromatography (GC) revealed the presence of chloroform and trichloroethylene. Further examination of the aqueous humate by the purge and trap procedure confirmed the association of chloroform and trichloroethylene with the humate. GC/mass spectrometry analyses of methylene chloride extract of the humate established the association of LMHs with the humate. Improved headspace capillary GC technique showed that the humate contained not only chloroform, trichloroethylene but several other LMHs in the range 190 to 4000ng·kg‐1.  相似文献   
158.
A model for assessing approval of a beach for recreational water activity was proposed. The model is based upon a sanitary survey together with intensive microbiological monitoring three times a day, five times a week for a month. In highly populated areas, continuous surveys once a day, five days a week are needed in order to assure the cleanliness and safety of these beaches.

Due to our intensive monitoring system, we can assure that Tel‐Aviv has one of the cleanest beaches near a metropolitan area in the Mediterranean Sea.  相似文献   
159.
The relationship between human resilience and environmental degradation was studied in the Sahel. The strongest predictors of human resilience were rate of environmental degradation, avoidance, problem solving and locus of control. Compared to pastoralists, agriculturalists were more stressed and marginalized. Women in all groups scored higher on marginalization and stress than men.  相似文献   
160.
Although half of the administrative units in China are said to have implemented their local Agenda 21, the promotion of sustainable communities is not pervasive. In this paper, we adopted a relatively untried mode of analysis and a socio-economic context to illustrate the potentials and failures of China's grassroots local government bodies in achieving sustainable waste management. Our study shows that, among the three main functions of sustainable waste management (ensuring environmental hygiene, provision of recycling logistics and changing the consumption pattern of the local community) for local governments, grassroots local government bodies in mainland China are only able to do the minimum, i.e. ensuring environmental hygiene and handling complaints. One of the reasons for the failure is that, despite the emphasis on capacity building in China's Agenda 21, the reality is that no action is taken to empower grassroots local government. Despite the high profile accorded by the Chinese central government to motivating local governments to formulate their own Agenda 21, local sustainability and waste management performance have little relevance to the appraisal systems of these government agents.  相似文献   
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