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Reviews of environmental contamination and toxicology
BOOK REVIEWS
161
background that will enable them to approach the complexities of environmental problems with improved understanding and confidence. G.T. B R O O K S
Department of Biochemistry & Physiology University of Reading Reading, U.K. ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
Reviews of Environmental Contamination and Toxicology. Volume 109 by G.W. Ware (Editor). Springer-Verlag, New York, 1989. 184 pp., hardcover, price DM 84.00 ISBN: 3-540-96902-0. "Reviews of Environmental Contamination and Toxicology", the continuation of "Residue Reviews" since 1986, aims to provide concise reviews of significant areas in the general field of interaction of foreign chemicals with the environment, including toxicological implications. Volume 109 contains a review on "Microbial metabolism of pesticides and structurally related compounds" (I.C. MacRae, pp. 1-87, 401 references), together with an account of mathematical modelling techniques developed in the USSR for "Predicting pesticides residues to reduce crop contamination" (E.I. Spynu, pp. 89-107, 39 references ) and an account of the history and activities of the Association of Official Analytical Chemists: 1964-1988 (H.C. Reynolds, pp. 109-136, 119 references). Together, these articles represent three key aspects of the problem of environmental contamination by chemicals, i.e. the requirement for reliable analytical methods, extensive exploration of degradation rates and metabolism, and especially the interpretation of highly complex inputsof data for future practical benefit. The first review assembles literature for 1981-1987 on microbial metabolism in soil and water, with a short first section on methodology. This is followed by an extensive review of the metabolism of specific groups of pesticides, sub-divided into halogenated hydrocarbons, organophosphates, carbamates, thiocarbamates, triazines, phenoxy-compounds, phenols, anilines, amides, ureapesticides, metallo- and metallo-organic compounds, pyrethroids, miscellaneous pesticides and related compounds. Selected compounds, microbial populations acting thereon and references to the original work are tabulated. A further short section on "Bound pesticide residues" lists some investigations using 14C-labelles compounds, indicating site of label, duration of experiment, soil type, fraction bound and literature references. Finally, there is a section on "Removal of pesticides from soil and water". The broad scope of the review dictates rather short entries for some of the individual chemicals discussed but the discussion is more extensive for
162
BOOKREVmWS
problem compounds such as 2,4,5-T. "Bound residues" are discussed in terms of recovery methods and identification, the influence of application methods and environmental conditions, and the significance of such residues for environmental contamination, since the question of their bioavailability remains controversial. The section on removal of pesticides from soil and water is short, reflecting perhaps the amount of work that remains to be done on this increasingly important aspect of environmental science. However, leading references to current developments in microbial methods are given and the review as a whole is a useful route of entry into the vast recent literature on this subject. Spynu's review provides a short general overview of pesticide use, with discussions on health effects, pesticide residue levels in crops and diet, and the multiple factors that affect residue levels. Against this background, there is much international effort toward the development of mathematical models that can accommodate a diversity of influential factors and provide acceptable predictions of pesticide behaviour under environmental conditions. The remainder of this article considers problems that arise in the modelling approach and specifically describes work in the U.S.S.R. on the development of algorithms for pesticide residue prediction, based on the identification of 22 factors, ranging from pesticide molecular weight to plant tissue properties, and likely to have a major influence on pesticide disappearance rates. Comparisons are given of actual and estimated degradation times and residue levels for various insecticides on fruits and an error of not more than 20% is claimed for values derived from the model. The prediction of pesticide behaviour in the total environment is a formidable challenge but progress is undoubtedly being made in this area (Klein et al., 1988 ). The A.O.A.C. was founded in 1884 and the account of its origins and development makes interesting reading. Early sections describe the administrative structure and evolution of the "referee system" and "methods adoption process", in which an existing or newly devised analytical method is rigorously evaluated by a group of analysts (collaborators) working independently. The end-point of this exacting process (the collaborative study) is, if successful, "official method" status for the technique and its publication in "Official Methods of Analysis of the A.O.A.C.". In the final section, on advances in methodology during the last 25 years, the evolution of methods for pesticide residues, metals in foods and mycotoxins are each traced chronologically. In that time for example, pesticide analysis has evolved from the measurement of single chemicals by chemical reactions combined with spectrophotometry, to modern multiresidue analysis involving simultaneous separation, detection and quantitation, particularly by gas-chromatography coupled with selective detectors. Scientists whose careers in pesticide-related subjects were developing during this period may remember with nostalgia the excitement that attended the introduction of the first electron-capture detec-
BOOKREVIEWS
163
tors for gas-chromatography. Newcomers to the field will also undoubtedly find citations of interest in this necessarily brief account. As we face the new environmental challenges of the 1990s, scientists engaged in this critically important area of analytical methods development can look back with justifiable pride on a long period of remarkable achievements in the public interest. REFERENCE Klein, W., Klein, A.W. and Lange, A.W. (Editors), 1988. Advances in environmental hazard and risk assessment 1987, Chemosphere 17, No 8, pp. 1381-1644. G.T. BROOKS
Department of Biochemistry and Physiology University of Reading Reading, U.K. HUMIC SUBSTANCES
Humic Substances and Their Role in the Environment, F.H. Frimmel and R.F. Christmans (Editors), Dahlem Workshop Reports: Life Science Report 41, Wiley and Sons, Chichester, New York, 271 pp., hardcover, £37.50, ISBN: 0-471-91817-2. The Dahlem workshop on humic substances was organized to bring together scientists from various disciplines, largely from the soil and aquatic areas, who were interested in advancing our knowledge of the structure and properties of humic acids. Problems of humic acid isolation from soils, sediments and waters, humic acid genesis, validity of humic acids structural hypotheses and structural characterization, and environmental reactions and functions of humic acids were discussed and explored by four working groups. Background review papers for problem areas were prepared prior to the workshop and circulated to all participants. These review papers served as the basis for discussion, comments, questions and suggestions for future research needs. Two working groups started their discussions simultaneously with participants not assigned to these work groups attending and participating on topics of their choice. In the working group on the isolation and nomenclature of humic and fulvic acids, Dr. J.W. Parsons reviewed the history of isolation and problems of obtaining unaltered constituents free of inorganic contaminants from soils and sediments. He raised many questions which one must consider when isolating humic substances. For example, should a flotation procedure be included prior to humic acid extraction in order to remove partially decom-
161
background that will enable them to approach the complexities of environmental problems with improved understanding and confidence. G.T. B R O O K S
Department of Biochemistry & Physiology University of Reading Reading, U.K. ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
Reviews of Environmental Contamination and Toxicology. Volume 109 by G.W. Ware (Editor). Springer-Verlag, New York, 1989. 184 pp., hardcover, price DM 84.00 ISBN: 3-540-96902-0. "Reviews of Environmental Contamination and Toxicology", the continuation of "Residue Reviews" since 1986, aims to provide concise reviews of significant areas in the general field of interaction of foreign chemicals with the environment, including toxicological implications. Volume 109 contains a review on "Microbial metabolism of pesticides and structurally related compounds" (I.C. MacRae, pp. 1-87, 401 references), together with an account of mathematical modelling techniques developed in the USSR for "Predicting pesticides residues to reduce crop contamination" (E.I. Spynu, pp. 89-107, 39 references ) and an account of the history and activities of the Association of Official Analytical Chemists: 1964-1988 (H.C. Reynolds, pp. 109-136, 119 references). Together, these articles represent three key aspects of the problem of environmental contamination by chemicals, i.e. the requirement for reliable analytical methods, extensive exploration of degradation rates and metabolism, and especially the interpretation of highly complex inputsof data for future practical benefit. The first review assembles literature for 1981-1987 on microbial metabolism in soil and water, with a short first section on methodology. This is followed by an extensive review of the metabolism of specific groups of pesticides, sub-divided into halogenated hydrocarbons, organophosphates, carbamates, thiocarbamates, triazines, phenoxy-compounds, phenols, anilines, amides, ureapesticides, metallo- and metallo-organic compounds, pyrethroids, miscellaneous pesticides and related compounds. Selected compounds, microbial populations acting thereon and references to the original work are tabulated. A further short section on "Bound pesticide residues" lists some investigations using 14C-labelles compounds, indicating site of label, duration of experiment, soil type, fraction bound and literature references. Finally, there is a section on "Removal of pesticides from soil and water". The broad scope of the review dictates rather short entries for some of the individual chemicals discussed but the discussion is more extensive for
162
BOOKREVmWS
problem compounds such as 2,4,5-T. "Bound residues" are discussed in terms of recovery methods and identification, the influence of application methods and environmental conditions, and the significance of such residues for environmental contamination, since the question of their bioavailability remains controversial. The section on removal of pesticides from soil and water is short, reflecting perhaps the amount of work that remains to be done on this increasingly important aspect of environmental science. However, leading references to current developments in microbial methods are given and the review as a whole is a useful route of entry into the vast recent literature on this subject. Spynu's review provides a short general overview of pesticide use, with discussions on health effects, pesticide residue levels in crops and diet, and the multiple factors that affect residue levels. Against this background, there is much international effort toward the development of mathematical models that can accommodate a diversity of influential factors and provide acceptable predictions of pesticide behaviour under environmental conditions. The remainder of this article considers problems that arise in the modelling approach and specifically describes work in the U.S.S.R. on the development of algorithms for pesticide residue prediction, based on the identification of 22 factors, ranging from pesticide molecular weight to plant tissue properties, and likely to have a major influence on pesticide disappearance rates. Comparisons are given of actual and estimated degradation times and residue levels for various insecticides on fruits and an error of not more than 20% is claimed for values derived from the model. The prediction of pesticide behaviour in the total environment is a formidable challenge but progress is undoubtedly being made in this area (Klein et al., 1988 ). The A.O.A.C. was founded in 1884 and the account of its origins and development makes interesting reading. Early sections describe the administrative structure and evolution of the "referee system" and "methods adoption process", in which an existing or newly devised analytical method is rigorously evaluated by a group of analysts (collaborators) working independently. The end-point of this exacting process (the collaborative study) is, if successful, "official method" status for the technique and its publication in "Official Methods of Analysis of the A.O.A.C.". In the final section, on advances in methodology during the last 25 years, the evolution of methods for pesticide residues, metals in foods and mycotoxins are each traced chronologically. In that time for example, pesticide analysis has evolved from the measurement of single chemicals by chemical reactions combined with spectrophotometry, to modern multiresidue analysis involving simultaneous separation, detection and quantitation, particularly by gas-chromatography coupled with selective detectors. Scientists whose careers in pesticide-related subjects were developing during this period may remember with nostalgia the excitement that attended the introduction of the first electron-capture detec-
BOOKREVIEWS
163
tors for gas-chromatography. Newcomers to the field will also undoubtedly find citations of interest in this necessarily brief account. As we face the new environmental challenges of the 1990s, scientists engaged in this critically important area of analytical methods development can look back with justifiable pride on a long period of remarkable achievements in the public interest. REFERENCE Klein, W., Klein, A.W. and Lange, A.W. (Editors), 1988. Advances in environmental hazard and risk assessment 1987, Chemosphere 17, No 8, pp. 1381-1644. G.T. BROOKS
Department of Biochemistry and Physiology University of Reading Reading, U.K. HUMIC SUBSTANCES
Humic Substances and Their Role in the Environment, F.H. Frimmel and R.F. Christmans (Editors), Dahlem Workshop Reports: Life Science Report 41, Wiley and Sons, Chichester, New York, 271 pp., hardcover, £37.50, ISBN: 0-471-91817-2. The Dahlem workshop on humic substances was organized to bring together scientists from various disciplines, largely from the soil and aquatic areas, who were interested in advancing our knowledge of the structure and properties of humic acids. Problems of humic acid isolation from soils, sediments and waters, humic acid genesis, validity of humic acids structural hypotheses and structural characterization, and environmental reactions and functions of humic acids were discussed and explored by four working groups. Background review papers for problem areas were prepared prior to the workshop and circulated to all participants. These review papers served as the basis for discussion, comments, questions and suggestions for future research needs. Two working groups started their discussions simultaneously with participants not assigned to these work groups attending and participating on topics of their choice. In the working group on the isolation and nomenclature of humic and fulvic acids, Dr. J.W. Parsons reviewed the history of isolation and problems of obtaining unaltered constituents free of inorganic contaminants from soils and sediments. He raised many questions which one must consider when isolating humic substances. For example, should a flotation procedure be included prior to humic acid extraction in order to remove partially decom-