環(huán)境專業(yè)畢業(yè)論文外文翻譯-環(huán)境工程-資料下載頁
2025-01-19 03:28本頁面
【導(dǎo)讀】環(huán)境保護的迫切需要，另一方面也是環(huán)境科學(xué)發(fā)展的必然結(jié)果。因此愈來愈受到許多國家環(huán)保機構(gòu)和有關(guān)國際性組織的重。在短短20多年中，就環(huán)境風險評價技術(shù)而言，大體上經(jīng)歷了。的發(fā)展，為風險評價體系建立的技術(shù)準備階段。美國國家科學(xué)院(NAS，鑒別，劑量一效應(yīng)關(guān)系評價，暴露評價和風險表征。并對各部分都作了明。在此基礎(chǔ)上，美國EPA. 制定和頒布了有關(guān)風險評價的一系列技術(shù)性文件、準則或指南。人體健康風險評價方面的。1989年，美國EPA還對1986年指南進行了修。因此，從1989年起，風險評價的科學(xué)體系基本形成，并處于不斷發(fā)。近幾年來，生態(tài)風險評價業(yè)已被人。們所重視，已處在同人體健康風險評價的同等地位。但是到目前為止，生。盡管有人將NAS模式加以改變后用于討。險評價指南制訂工作大綱[11]，原則上給出了生態(tài)風險評價的框架。進行終點選擇和有關(guān)評價中假設(shè)的提出。問題闡述是確定評價范圍和制定。向野外情況外推，由高劑量向低劑量外推等。將對環(huán)境科學(xué)理論研究有新的推進。
【正文】 ment, characterized by the exposed population. In the ecological risk assessment, exposure assessment is relative harder than human health exposure assessment, especially for the characterization of exposure groups, for different species, their habitat very different environment, such as environment, terrestrial environment and other specific environmental and so on. At present, the definition of ecological exposure evaluation has not been fully unified。 generally exposure assessment is the determination of ecological pollutants distribution of space and time, the existence of morphological, bioeffectiveness and ecological ponents of concern to the contact situation. Ecological exposure assessment is the most basic ponent of the system of the process of ecological risk assessment as a result of exposure to the plex nature of exposure is not a description could apply to all of the ecological risk assessment. Exposure assessment of many factors there are uncertainties. The reasons are that there is a risk that the inplete understanding of the population, the effectiveness factor of pollutants not understand a single, especially the multidose exposure to a mixture of response do not have a profound understanding of the law, as well as laboratory results to the field of the different spatial and temporal scales difficulties and so on. It is clear that ecological exposure assessment is plex than human exposure assessment, the key points are pollutants and anisms must be considered, as well as ecosystems, pollution and environment interaction, mutual influence. Therefore, we must strengthen the evaluation of research methods and techniques. 4. Deal of uncertainty It is always the major problem that Deal with uncertainty in risk assessment. Uncertainties in extrapolating from the variety processes, such as: interspecies extrapolation, between different levels of biological anization extrapolation from laboratory to field extrapolation cases, from highdose to lowdose extrapolation and others. Therefore, it is the key technical problems to address that the uncertainty dealing with quantitative risk assessment. We need to develop extrapolation theory, and built up the appropriate extrapolation model. In short, with the Environmental Protection has entered a new era, it can be predicted that environmental risk assessment studies will write fresh history about the survival of mankind, environment protect and improve the natural environment to make new contributions to the theoretical advancing of environmental science study.
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