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Chlorinated phenocy acids and their dioxins
238
BOOK REVIEWS
reserves rather than national parks, on small areas because so few large ones remained, and on man-made environments as well as semi-natural. Dr Sheail has extracted a great deal of new information from the available documents and the conservation ecologist is strongly recommended to read this account in order to get a deeper perspective of his own work and interests. With this type of historical background the opportunity has been prepared for a scientific analysis of the achievements of past policies and for a look at what must be done in the future. E.D.
Chlorinated Phenoxy Acids and their Dioxins. Edited by C. Ramel. Report from a conference arranged by the Royal Swedish Academy of Sciences in 1977. Swedish Natural Science Research Council, Stockholm. 1978. 301 pp.
The chlorinated phenoxy acids discussed in the book are the widely used herbicides MCPA, 2,4-D and 2,4,5-T. They achieved some notoriety in 1969 and 1970 mainly as a result of the defoliation programme in Vietnam and the news from the United States that 2,4,5-T appeared to be teratogenic. This was followed by the tragedy of 1976 when an accident at a factory in Seveso, Italy, liberated a chemical cloud containing T C D D (dioxin), an impurity of commercial 2,4,5-T. This book is a broad, but detailed, appraisal of our current knowledge of these chemicals. Naturally it has a Swedish bias, but it is of great relevance to any scientist interested in this topic. Because of the concern shown by the public about these extensively-used compounds (200,000 metric tons of active ingredient are estimated in the book to be applied each year), this information will one day hopefully reach a wider audience. There are sections on chemistry, plant physiology, toxicology, genetics, ecology and economy, preceded by a lucid summary. In addition there is an important account dealing with the conclusions and recommendations of the conference. The book makes clear that perhaps the greatest direct environmental hazard is from contamination following an industrial mishap. The mobilisation of scientists to monitor the events at Seveso demonstrates the response of the authorities to such a crisis. The chapter on analysis of dioxin in the Seveso area has no less than 39 authors. Dioxin is stable and toxic and is described by one author as 'perhaps the most poisonous substance ever to have been synthesised'. But it is concluded that T C D D should not cause health or environmental risks if levels in the herbicide preparations remain less than 0.1 ppm. Environmentalists may be slightly disappointed to find that the account of the phenoxy acid problem in Sweden is delivered by a member of the chemical industry. Nevertheless this article and the book in general present a reasonable and rational appraisal of potential environmental problems associated with these herbicides.
BOOK REVIEWS
239
Apart from discussions of effects on man, laboratory animals and soil organisms, there is little information concerning effects on non-target organisms. This seems to be a failing of the scientific community rather than of this publication. It points to a need for precise information on the effects of herbicides on wild plants and on the animals that depend on them for food and shelter. All too often, however, if one confronts a research botanist with this shortcoming, the answer is 'why study the treatment of plants with herbicides ?--they die'. ARNOLD COOKE
BOOK REVIEWS
reserves rather than national parks, on small areas because so few large ones remained, and on man-made environments as well as semi-natural. Dr Sheail has extracted a great deal of new information from the available documents and the conservation ecologist is strongly recommended to read this account in order to get a deeper perspective of his own work and interests. With this type of historical background the opportunity has been prepared for a scientific analysis of the achievements of past policies and for a look at what must be done in the future. E.D.
Chlorinated Phenoxy Acids and their Dioxins. Edited by C. Ramel. Report from a conference arranged by the Royal Swedish Academy of Sciences in 1977. Swedish Natural Science Research Council, Stockholm. 1978. 301 pp.
The chlorinated phenoxy acids discussed in the book are the widely used herbicides MCPA, 2,4-D and 2,4,5-T. They achieved some notoriety in 1969 and 1970 mainly as a result of the defoliation programme in Vietnam and the news from the United States that 2,4,5-T appeared to be teratogenic. This was followed by the tragedy of 1976 when an accident at a factory in Seveso, Italy, liberated a chemical cloud containing T C D D (dioxin), an impurity of commercial 2,4,5-T. This book is a broad, but detailed, appraisal of our current knowledge of these chemicals. Naturally it has a Swedish bias, but it is of great relevance to any scientist interested in this topic. Because of the concern shown by the public about these extensively-used compounds (200,000 metric tons of active ingredient are estimated in the book to be applied each year), this information will one day hopefully reach a wider audience. There are sections on chemistry, plant physiology, toxicology, genetics, ecology and economy, preceded by a lucid summary. In addition there is an important account dealing with the conclusions and recommendations of the conference. The book makes clear that perhaps the greatest direct environmental hazard is from contamination following an industrial mishap. The mobilisation of scientists to monitor the events at Seveso demonstrates the response of the authorities to such a crisis. The chapter on analysis of dioxin in the Seveso area has no less than 39 authors. Dioxin is stable and toxic and is described by one author as 'perhaps the most poisonous substance ever to have been synthesised'. But it is concluded that T C D D should not cause health or environmental risks if levels in the herbicide preparations remain less than 0.1 ppm. Environmentalists may be slightly disappointed to find that the account of the phenoxy acid problem in Sweden is delivered by a member of the chemical industry. Nevertheless this article and the book in general present a reasonable and rational appraisal of potential environmental problems associated with these herbicides.
BOOK REVIEWS
239
Apart from discussions of effects on man, laboratory animals and soil organisms, there is little information concerning effects on non-target organisms. This seems to be a failing of the scientific community rather than of this publication. It points to a need for precise information on the effects of herbicides on wild plants and on the animals that depend on them for food and shelter. All too often, however, if one confronts a research botanist with this shortcoming, the answer is 'why study the treatment of plants with herbicides ?--they die'. ARNOLD COOKE