環(huán)境專業(yè)畢業(yè)論文外文翻譯

1、<p><b>　　文獻(xiàn)翻譯</b></p><p>　　環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)是當(dāng)前環(huán)境保護(hù)工作中一個(gè)新興領(lǐng)域，它的誕生一方面是環(huán)境保護(hù)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。標(biāo)志著環(huán)境保護(hù)的一次重要戰(zhàn)略轉(zhuǎn)折，由原先污染后的治理轉(zhuǎn)變?yōu)槲廴厩暗念A(yù)測(cè)和實(shí)行有效管理。因此愈來愈受到許多國(guó)家環(huán)保機(jī)構(gòu)和有關(guān)國(guó)際性組織的重視。</p><p>　　風(fēng)險(xiǎn)評(píng)價(jià)興起于七十年代

2、幾個(gè)工業(yè)發(fā)達(dá)國(guó)家，尤以美國(guó)在這方面的研究獨(dú)領(lǐng)風(fēng)騷。在短短20多年中，就環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)技術(shù)而言，大體上經(jīng)歷了三個(gè)時(shí)期：七十年代至八十年代初，風(fēng)險(xiǎn)評(píng)價(jià)處于萌芽階段，風(fēng)險(xiǎn)評(píng)價(jià)內(nèi)涵不甚明確，僅僅采取毒性鑒定的方法；八十年代中，風(fēng)險(xiǎn)評(píng)價(jià)得到很大的發(fā)展，為風(fēng)險(xiǎn)評(píng)價(jià)體系建立的技術(shù)準(zhǔn)備階段。美國(guó)國(guó)家科學(xué)院(NAS，1983)[1]提出風(fēng)險(xiǎn)評(píng)價(jià)由四個(gè)部分組成，稱為風(fēng)險(xiǎn)評(píng)價(jià)“四步法”即危害鑒別，劑量一效應(yīng)關(guān)系評(píng)價(jià)，暴露評(píng)價(jià)和風(fēng)險(xiǎn)表征。并對(duì)各部分都作了明確的定

3、義。由此，風(fēng)險(xiǎn)評(píng)價(jià)的基本框架已經(jīng)形成。在此基礎(chǔ)上，美國(guó)EPA制定和頒布了有關(guān)風(fēng)險(xiǎn)評(píng)價(jià)的一系列技術(shù)性文件、準(zhǔn)則或指南。但大多是人體健康風(fēng)險(xiǎn)評(píng)價(jià)方面的。例如，1986年發(fā)布了致癌風(fēng)險(xiǎn)評(píng)價(jià)、[2]致畸風(fēng)險(xiǎn)評(píng)價(jià)、[3]化學(xué)混合物健康風(fēng)險(xiǎn)評(píng)價(jià)、[4]發(fā)育毒物健康風(fēng)險(xiǎn)評(píng)價(jià)、[5]暴露評(píng)價(jià)、[6]超級(jí)基金場(chǎng)地（Superfund sites）危害評(píng)價(jià)和風(fēng)險(xiǎn)評(píng)價(jià)[7]等指南。1988年又發(fā)布了內(nèi)吸毒物(sytemictoxicants)[8]和男女繁殖

4、性能毒物[9,10]等評(píng)價(jià)指南。1989年，美國(guó)EPA還對(duì)1986年指南進(jìn)行了修改。因此，從198</p><p>　　由此可見，原先的風(fēng)險(xiǎn)評(píng)價(jià)主要限于人體健康風(fēng)險(xiǎn)評(píng)價(jià)，許多有害廢物管理也是著眼于人體健康風(fēng)險(xiǎn)進(jìn)行的。近幾年來，生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)業(yè)已被人們所重視，已處在同人體健康風(fēng)險(xiǎn)評(píng)價(jià)的同等地位。但是到目前為止，生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)還沒有一套方法指南。盡管有人將NAS模式加以改變后用于討論生態(tài)風(fēng)險(xiǎn)問題，生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)原則上也可按

5、其四個(gè)方面進(jìn)行，但由于生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)不完全等同于人體健康風(fēng)險(xiǎn)評(píng)價(jià)，用于人體健康風(fēng)險(xiǎn)評(píng)價(jià)的一系列方法指南并不完全適用于生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)。因此美國(guó)EPA從1989年以來一直致力于生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)指南的制訂工作，1992年確定了一個(gè)生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)指南制訂工作大綱[11]，原則上給出了生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)的框架。從研究?jī)?nèi)容上看，大致上與NAS提出的“四步法”相同，但每一方面的重點(diǎn)和方法又有不同的內(nèi)容。該大綱將生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)過程分為三步：第一步為問題闡述(Proble

6、m formulation)，描述目標(biāo)污染物特性和有風(fēng)險(xiǎn)生態(tài)系統(tǒng)，進(jìn)行終點(diǎn)選擇和有關(guān)評(píng)價(jià)中假設(shè)的提出。問題闡述是確定評(píng)價(jià)范圍和制定計(jì)劃的過程；第二步為分析階段(analysis phase)，主要從暴露表征和生態(tài)效應(yīng)表征兩個(gè)方面進(jìn)行；第三步為風(fēng)險(xiǎn)表征。</p><p>　　顯然，目前國(guó)外環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)主要包括人體健康風(fēng)險(xiǎn)評(píng)價(jià)和生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)兩方面，風(fēng)險(xiǎn)評(píng)價(jià)的科學(xué)體系已基本形成。相對(duì)來說，人體健康風(fēng)險(xiǎn)評(píng)價(jià)的方法基本定型

7、，生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)正處在總結(jié)、完善階段。總的來說，目前國(guó)外環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)具有如下的特點(diǎn)和趨勢(shì)：</p><p>　　· 研究熱點(diǎn)已由人體健康風(fēng)險(xiǎn)評(píng)價(jià)轉(zhuǎn)移到生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)；</p><p>　　· 從污染物數(shù)量來說，已由單一污染物作用進(jìn)一步考慮到多種污染物的復(fù)合作用；</p><p>　　· 從環(huán)境風(fēng)險(xiǎn)類型來

8、說，不僅考慮化學(xué)污染物，特別是有毒有害化學(xué)物，而且還要考慮到非化學(xué)因子對(duì)環(huán)境的不利影響；</p><p>　　· 從評(píng)價(jià)范圍方面來說，由局部環(huán)境風(fēng)險(xiǎn)發(fā)展到區(qū)域性環(huán)境風(fēng)險(xiǎn)，乃至全球環(huán)境風(fēng)險(xiǎn)；</p><p>　　· 生態(tài)風(fēng)險(xiǎn)不僅僅只考慮到生物個(gè)體和群體，而且考慮到群落、甚至整個(gè)生態(tài)系統(tǒng)；</p><p>　　·

9、 技術(shù)處理上由定性向半定量、定量方向發(fā)展。</p><p>　　環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)技術(shù)，特別是生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)，還有許多問題有待研究，其中主要的有以下幾方面：</p><p>　　1．評(píng)價(jià)終點(diǎn)的選擇 人體健康風(fēng)險(xiǎn)評(píng)價(jià)的終點(diǎn)，只有一個(gè)物種(受體為人)，而生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)的終點(diǎn)卻不止一個(gè)，終點(diǎn)選擇就成了生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)過程的關(guān)鍵。對(duì)任何不同組織等級(jí)都有終點(diǎn)選擇問題，終點(diǎn)選擇原則上根據(jù)所關(guān)注的生態(tài)系統(tǒng)

10、和污染物特性來進(jìn)行，對(duì)生態(tài)系統(tǒng)和污染物特性了解得愈深刻，終點(diǎn)選擇就愈準(zhǔn)確。由于生態(tài)系統(tǒng)復(fù)雜性，不同評(píng)價(jià)人員可以選擇不同的終點(diǎn)，因此目前迫切需要有一個(gè)統(tǒng)一的方法來確定生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)的終點(diǎn)。</p><p>　　2．模型優(yōu)化 模型在風(fēng)險(xiǎn)評(píng)價(jià)中的重要性是顯而易見的，因?yàn)轱L(fēng)險(xiǎn)評(píng)價(jià)是研究人為活動(dòng)引起環(huán)境不利影響的可能性，是根據(jù)有限的已知資料預(yù)測(cè)未知后果的過程，這就需要應(yīng)用大量的數(shù)學(xué)模型才能完成。模型的優(yōu)劣直接關(guān)系到整個(gè)風(fēng)險(xiǎn)評(píng)

11、價(jià)結(jié)果的準(zhǔn)確性。風(fēng)險(xiǎn)評(píng)價(jià)涉及的模型很多，主要有污染物環(huán)境轉(zhuǎn)歸模型、污染物時(shí)空分布模型、暴露模型、生物體分布模型、外推模型、風(fēng)險(xiǎn)計(jì)算模型等。風(fēng)險(xiǎn)評(píng)價(jià)就是由這些模型的組合，借助于計(jì)算機(jī)來連串在一體的。隨著風(fēng)險(xiǎn)評(píng)價(jià)越來越復(fù)雜，準(zhǔn)確性要求越來越高，發(fā)展和完善各種數(shù)學(xué)模型始終是風(fēng)險(xiǎn)評(píng)價(jià)研究的重要方面。</p><p>　　3．生態(tài)暴露評(píng)價(jià) 在人體健康風(fēng)險(xiǎn)評(píng)價(jià)中，暴露評(píng)價(jià)是測(cè)定人體暴露值大小、頻率、途徑和暴露時(shí)間，表征受暴露

12、的人群。在生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)中、暴露評(píng)價(jià)相對(duì)人體健康暴露評(píng)價(jià)來說是特別困難的，尤其對(duì)暴露群體的表征，針對(duì)不同物種，它們棲息地環(huán)境差異很大，如水生環(huán)境、陸生環(huán)境和其他特定環(huán)境等。目前對(duì)生態(tài)暴露評(píng)價(jià)的定義還沒有完全統(tǒng)一，一般認(rèn)為生態(tài)暴露評(píng)價(jià)是測(cè)定污染物的空間和時(shí)間分布、存在形態(tài)、生物有效性以及與所關(guān)注的生態(tài)組分的接觸狀況。生態(tài)暴露評(píng)價(jià)是生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)過程中最基本的組成部分，由于暴露系統(tǒng)的復(fù)雜性，目前還沒有一個(gè)暴露的描述能適用所有的生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)。由于

13、對(duì)存在風(fēng)險(xiǎn)的種群認(rèn)識(shí)不完全、污染物有效性的因子了解不夠、單一、特別是多種混合物暴露的劑量一響應(yīng)規(guī)律認(rèn)識(shí)不深入，以及將實(shí)驗(yàn)室結(jié)果外推到野外的不同時(shí)空范圍的困難等，暴露評(píng)價(jià)中的許多因子都存在不確定性。顯然，生態(tài)暴露評(píng)價(jià)遠(yuǎn)比人體暴露評(píng)價(jià)復(fù)雜，關(guān)鍵必須考慮污染物與生物體以及生態(tài)系統(tǒng)、污染物與環(huán)境間的相互作用、相互影響。因此，必須加強(qiáng)這方面評(píng)價(jià)方法和技術(shù)的研究。</p><p>　　4．不確定性處理 不確定性處理一直是風(fēng)險(xiǎn)

14、評(píng)價(jià)中的主要問題。不確定性來源于各種外推過程，例如：物種間外推、不同等級(jí)生物組織間外推、由實(shí)驗(yàn)室向野外情況外推，由高劑量向低劑量外推等。因此對(duì)不確定性的定量化處理是風(fēng)險(xiǎn)評(píng)價(jià)必須解決的關(guān)鍵技術(shù)問題。要發(fā)展各種外推理論，建立合適的外推模型。 總之，隨著環(huán)境保護(hù)進(jìn)入一個(gè)新的時(shí)代，可以預(yù)見，環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)研究必將對(duì)人類生存及自然環(huán)境的保護(hù)和改善作出新的貢獻(xiàn)，并將對(duì)環(huán)境科學(xué)理論研究有新的推進(jìn)。</p><p>　　Envir

15、onmental risk assessment is an emerging environmental protection work in the field; on the other hand, it is the birth of the urgent need for environmental protection, environmental science, and the inevitable result of

16、the development. It is a transition which marks an important environmental protection strategy, so that from the management of pollution to the pre-pollution forecast and the implementation of effective management. Many

17、countries’ environmental protection agencies and releva</p><p>　　The risk assessment emerged in several industrialized countries in 1970’s; particularly the United States is the leading research in this area

18、. In a short span of 20 years, generally, the environmental risk assessment technology has gone through three periods: in 1970’s to 1980’s, risk assessment was infancy, the connotation of risk assessment is un-clear, jus

19、t using the toxicity identified method; in 1980’s, the risk assessment has been development a lot, it was the technical preparation phase </p><p>　　It can be seen that the original risk assessment is mainly

20、limited to human health risk assessment; hazardous waste management is also focus on the human health risks. In recent years, the ecological risk assessment has been attention, and becomes the same status with the human

21、health risk assessment. So far, ecological risk assessment methodology does not have a guide, although some people will change NAS models for discussion the question of ecological risk, ecological risk assessment may als

22、o</p><p>　　Admittedly, environmental risk assessment includes human health and ecological risk assessment in abroad, and risk assessment of the scientific system has been basically formed. Relatively speakin

23、g, the methods of human health risk assessment have been shape; ecological risk assessment is concluding and becomes satisfactory. In general, the current environmental risk assessment follows several characteristics and

24、 trends in abroad:</p><p>　　Research focus from human health risk assessment transferred to the ecological risk assessment;</p><p>　　From the amount of pollutants, from thinking the role of a si

25、ngle pollutant taking into account the complex role of a variety of pollutants; </p><p>　　Environmental risk from the type of example, not only take into account chemical pollutants, especially toxic and haz

26、ardous chemicals, but also non-chemical factors take into account the adverse effects on the environment; </p><p>　　From the scope of the evaluation, from local environmental risks development to regional en

27、vironmental risks, as well as global environmental risks; </p><p>　　Ecological risk, not only taking into accounts biological individuals and groups, but also taking into account the community, evens the ent

28、ire ecosystem; </p><p>　　Processing technical is from semi-quantitative to quantitative direction.</p><p>　　Environmental risk assessment techniques, especially the ecological risk assessment st

29、ill have many issues can be examined, such as:</p><p>　　1.Evaluation the end choice</p><p>　　The only end is human (human receptor) for human health risk assessment, and ecological risk assessm

30、ent is more than one end, the choice of end is the key of ecological risk assessment process. The choice of destination is the problem for different levels any organization, the end of selection based on the principle of

31、 ecosystem characteristics and pollutants, and the more deep understanding about pollutants and ecosystem characteristics, the more accurate the end of choice will be. Due to the c</p><p>　　2. Model optimiza

32、tion </p><p>　　It is obvious to see the important of model of risk assessment, because the risk assessment is to study the environment caused by human activities adversely affect the possibility is based on

33、limited information to predict the unknown consequences of known process, which requires the application of a large number of mathematical models to complete. The accurate results depend on the quality of model of risk

34、assessment. Risk assessment model involved a lot of things, such as pollutants in the en</p><p>　　3. Ecological exposure assessment </p><p>　　Exposure assessment is the determination of human ex

35、posure to the value of the size, frequency, channels, and exposure time in human health risk assessment, characterized by the exposed population. In the ecological risk assessment, exposure assessment is relative harder

36、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 speci

37、fic envi</p><p>　　4. Deal of uncertainty </p><p>　　It is always the major problem that Deal with uncertainty in risk assessment. Uncertainties in extrapolating from the variety processes, such a

38、s: inter-species extrapolation, between different levels of biological organization extrapolation from laboratory to field extrapolation cases, from high-dose to low-dose extrapolation and others. Therefore, it is the ke