Martin Alexander’s review on the topic “Aging, bioavailability, and overestimation of risk from environmental pollutants” presents information about organic compounds which while aging in soil lose their bioavailability. He emphasizes the fact that current methods of measuring decline of bioavailability proved to be not efficient enough. He evaluates flaws of these current methods pointing out at the problems the inefficiency of the methods may involve. The review makes use of reliable facts and is very educational but there is a need to discuss its structure and presentation of information more thoroughly with the reason of finding out which features a literature review should possess and what it is supposed to contain in order to be instructive and informative.
What should be mentioned above all is that Martin Alexander pays special attention to grouping the research on similar and relative topics. He presents the overview of the early evidence on the subject: “The early information came from studies of concentration of pesticides in the field measured for long periods of time and from measurements of toxicity of pesticides to invertebrates and plants” (Martin Alexander 557). This is followed by recent evidence which on the basis of the early evidence aims to show “that the accessibility of several pollutants to bacteria and earthworms decreases as the pollutants age in soil” (Martin Alexander 558). By contrasting early and recent evidence the author makes it possible to find out that with time the pollutants become less absorbed by the small organisms which contributes greatly to the development of the subject.
The overall information the author provides in the literature review deals with bioavailability of chemicals, traditional methods which are as a rule used to analyze polluted soil and toxicological significance of aging which influences genotoxic compounds of soil. On the whole, the review contains information about different methods of analyzing effects of pollutants which are produced on the living organisms. He also presents information about the chemicals which can cause cancer referring to the genotoxic compounds which, modifying DNA, are able to alter genes and, as a result, serve as a cause for developing cancer, and carcinogens which are considered to be the substances causing cancer. However, at this the author points out that, for instance, genotoxic compounds lose their ability of modifying DNA in the process of aging.
When arranging the review the author starts with the abstract which presents the problem and emphasizes the necessity of the additional research in the area he is going to discuss. Further he describes the essence of the current methods applied to analyze polluted soil and proves their inefficiency supporting this by discussing early and recent methods of analysis; then he moves to the discussion of the toxicological significance of aging. This is followed by incorrect analytical methodologies, the section which thoroughly considers all the discussed methods and is followed by new assay methods where the author addresses the key question: “If bioavailability changes over time and can’t be predicted, how can you predict the risk of exposure?” (Martin Alexander 561). The rhetorical effect of such an arrangement lies in making the audience think the situation over after being informed about the problem raised in the review. Placing the key question almost at the end of the review, the author emphasizes the importance of the issue and pushes to make up the reader’s own solution to the problem.
The author’s reason for reviewing this subject lies in the importance of informing people about bioavailability of aged chemicals. The matter is that being misinformed about the danger of chemicals people tend to remediate the sites which do not need cleanup which leads “to expenditure of funds that could be used to decontaminate additional areas” (Martin Alexander 562). This is why the notion bioavailability of aged compounds should be paid proper attention to.
The second review “Lung Cancer Risk after Exposure to Polycyclic Aromatic Hydrocarbons“ deals with the discussion of polycyclic aromatic hydrocarbon mixtures which are believed to be carcinogens. It is emphasized in the review that these mixtures are proved to cause cancer in experimental animals and, as epidemiological studies testify, cause lung and bladder cancer in the exposed workers. The review discussed the importance of exposure-response relationship since it is necessary to be certain in the existence of cancer risk for setting environmental and occupational standards. It is stated that a number of studies has been conducted on the subject though quantitative assessment of the risk has not been used in any of them. Therefore the review aims at utilizing the evidence published by a number of scientists on the subject and obtaining an estimate of the possible risks by observing exposure-response relationship of PAH (Polycyclic Aromatic Hydrocarbons). The structure of this review resembles to some extent Martin Alexander’s “Aging, bioavailability, and overestimation of risk from environmental pollutants” though there are also evident differences in these two works. It is necessary to compare these two reviews in order to trace the elements of the literature review as a genre and to find out which structure it is supposed to have.
Discussing the similarities between these two reviews it should be noted that both of them have an abstract which makes it a necessary element of the review. Just like in Alexander’s review, the abstract of “Lung Cancer Risk after Exposure to Polycyclic Aromatic Hydrocarbons” describes the discussed problem and shows the necessity of additional research in the specific area of studies. Thus, the review states that according to the conducted studies, “there was no statistically significant variation of URRs (Unit Relative Risk) within industry or in relation to study design (including whether adjusted for smoking), or source of exposure information” and “limited information on total dust exposure did not suggest that dust exposure was an important confounder or modified the effect” (Ben Armstrong, Emma Hutchinson, John Unwin & Tony Fletcher970) which influenced the risk assessment discussed in the review. Another similarity lies in presenting the obtained data regarding exposure estimation, duration of exposure and other constituents of the review which relate to the subject. This reminds of Alexander’s discussing early and recent methods of analyzing polluted soil.
However, certain differences between the two reviews are evident. One of the most obvious is that “Lung Cancer Risk after Exposure to Polycyclic Aromatic Hydrocarbons” presents information from a slightly different perspective. The matter is that Alexander’s review did not have a separate area containing the sources used in it whereas “Lung Cancer Risk after Exposure to Polycyclic Aromatic Hydrocarbons” has a specific section enumerating the publications and electronic databases the contributors to the review searched. Moreover, Alexander’s presentation of the can be characterized by a critical approach to them which consisted in listing the flaws of the methods used earlier and insisted on applying other ones which were proved to be more efficient. The authors of the second review, in their turn, present the study based on the research of other scientists which they, in most of the cases, support rather than criticize.
Taking into consideration the number of similarities between the literature reviews “Aging, bioavailability, and overestimation of risk from environmental pollutants” and “Lung Cancer Risk after Exposure to Polycyclic Aromatic Hydrocarbons”, it can be concluded that they are to some extent similar in structure but different in the presentation of the information with the former analyzing the sources critically and the latter using the data of the sources for the meta-analysis.
On the whole, literature review, unlike the book review which summarizes the events described in the book and analyzes the actions of the characters, is a survey of different sources, including books and scholarly articles as well as dissertations and other sources which are relevant for the research conducted in a particular area of studies. The main purpose of the literature review is to objectively present the literature which was published on the topic under discussion. Each genre of writing has its peculiar structure and like, for instance, an essay which has introduction, body and conclusion, literature review has its own structure and elements. It is necessary to discuss all the features of the literature review for it would help to keep to the structure and compile it properly.
To begin with, the structure of the review depends greatly on its thesis as well as the research area where the studies are conducted. One of the most important points is that no description of the works as such should be provided. Instead, various theories, approaches, controversial issues and questions should be paid attention to. The discussion of the sources should be limited to a certain number of topic areas which will be connected with the relevant sources. It is also necessary to use correspondent link-words and phrases specifying adding of new information in support of the point or contrasting the information with what has been written.
Secondly, the literature review, like a research, is supposed to have four main stages. The first is the formulation of the problem, the section which specifies the files of science under discussion; then comes literature search which involves the materials which were used to explore the subject; these are followed by data evaluation the purpose of which is to state which literature contributes to the exploration of the topic most of all; and the final component is analysis and interpretation which is the discussion of what can be concluded from the literature relevant to the subject.
There also exist certain elements the literature review should contain. Firstly, this is an overview of the subject under consideration with outlining the main objectives set by the literature review. Then all the sources should be divided into separate categories, for instance, the ones for and against the particular position or the ones which present an alternative view. Furthermore, the sources should be compared with each other and their distinctive features should be pointed out. And the last goes to the conclusion which discusses which of the sources are the most relevant, convincing and informative.
In conclusion it should be added that the literature review is not supposed to contain any new information. One of its main features is objectiveness and correspondence to the primary subject of the research in a particular area of studies.
Works Cited
Alexander, M. “Aging, Bioavailability, and Overestimation of Risk from Environmental Polluta I’m nts”. Environmental Science & Technology 34.20 (2000): 4259-65.
Armstrong, B., Hutchinson, E., Unwin, J., Fletcher, T. “Lung Cancer Risk after Exposure to Polycyclic Aromatic Hydrocarbons: A Review and Meta-Analysis”. Environmental Health Perspectives. 112.9 (2004): 970-978.