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Phosphorous in freshwater ecosystems
291 potential risks to the health of man from carcinogens after chronic exposure. The micro-pollutants selected were identified following a survey of 14 drinking waters derived from surface and groundwaters. While the title might infer that the text is devoted to 'environmental' aspects of toxicology, this is often taken to infer chronic exposure to low levels of contamination, which is the most difficult field to quantify in relation to well defined effects. However, this aspect, although discussed, represents a minor component of the text, which primarily relates to toxicity studies on experimental animals, especially rodents. Unfortunately, there is no discussion concerning the relevance of extrapolating animal data to man, neither is there any substantial discussion on effects likely to be associated with freshwater biota. A chapter (rather than a brief introduction) would be welcomed in order to discuss this subject; for example, a summary of the most recent approaches and methods in environmental toxicology, albeit that past practices are all that are available in the literature. The authors have included in their study a wide selection of compounds, but certain important omissions are apparent, for example polycyclic aromatic hydrocarbons ( > 3 aromatic rings) and many widely used pesticides. While this book reviews the toxicology of micro-pollutants, it is to be regretted that the data is not presented in relation to environmental concentrations, hence there is no clear indication of what pollutants in drinking water are of real concern to man? This book will provide an excellent reference work for environmental toxicologists and the water industry.
Tavistock (United Kingdom)
E.I. Hamilton
Phosphorous in Freshwater Ecosystems, edited by G. Persson and M. Jansson, Kluwer Academic Publishers, 1989, 340 pp. Price: £82.00, U.S.$142.50. This book presents the proceedings of a symposium held in Uppsala, Sweden in 1985 and is a reprint of a publication in Hydrobiologia, Vol. 170, 1988. Despite the rather long gestation period the contents of this multi-author book should be of interest to a wide audience. This book brings together many aspects of phosphorus in freshwater ecosystems which have reached a degree of maturity, hence are appropriate for a textbook, as distinct from those about which scientific controversy or challenge still remain. Most aspects of the phosphorus cycle are discussed and the role played by biota and sediment is emphasised. Attention is directed to the drawbacks of placing too much reliance upon generalised aspects of phosphorus recycling in freshwaters and a need to consider the details of processes which take place in particular systems. While the results of laboratory experiments may be interesting, such findings still need to be proven in the field before they are accepted. While most aspects of the chemistry and biology of phosphorus are discussed, the tendency is to
292 consider the behaviour of natural systems to the exclusion of an in-depth evaluation of polluted systems. Overall, this is an excellent text book which presents the subject in a holistic manner.
Tavistock (United Kingdom)
E.I. Hamilton
The Environmental Record in Glaciers and Ice Sheets, edited by H. Oeschger and C.C. Langway Jr, Dahlem Workshop Report PC8, John Wiley & Sons, Chichester, U.K., 1989, 400 pp. Price: £47.50. The Dahlem conferences have a unique structure. There are four conferences a year for 40 or 50 participants, by invitation only. The result of each conference is a book like this one, written while the discussion is still fresh. The participants of this workshop worked in four discussion groups of twelve members each. Each group was responsible for a specific problem: (1)How do glaciers record environmental processes and preserve information? (2)What anthropogenic impacts are recorded in glaciers? (3)How can ice core chronology be established? (4)What does the long-term ice core record tell us about global changes in the environment? Group 1 concluded that, although unambiguous translation of ice core studies is neither straightforward nor simple, the environmental record is well preserved in cold glaciers, but that more research is needed to study the atmosphere-to-snow-surface transfer functions and related processes. Group 2 deduced that the determination of a deep ice core age-scale is currently a weak point in the research. The current methods of dating ice range from numerical modelling and isotope dating to changes in chronology brought about by variations in the impurity concentrations and in situ temperature changes. Much attention was given to methods employing annual layer counting, solar and terrestrial radioactivity, comparison with sea sediment and dendrochronological records, and the Earth's orbital changes. The group agreed that there is much potential in new dating techniques based on AMS (accelerator mass spectrometry) and RIMS (resonance ionization mass spectrometry). They also concluded that annual layers should be continuously measured further back in time. Group 3 focussed their considerations on the anthropogenic records contained in ice cores. Earlier research had established that the preindustrial concentrations of CO2, CH4 and N20 are now clearly being increased by Man's activity. It was inferred that if it were not for the CO2 emission due to deforestation and the increase in fossil fuel consumption, today's atmospheric CO2 concentration would probably have remained in the 280 + 10 ppm range. It was observed that, during the past 2000 years, the reported lead concentrations in Greenland deposits show a 200-fold increase. Increasing trends in NO~ and SO~- concentrations are also evident during the past 200 years in Greenland.
Tavistock (United Kingdom)
E.I. Hamilton
Phosphorous in Freshwater Ecosystems, edited by G. Persson and M. Jansson, Kluwer Academic Publishers, 1989, 340 pp. Price: £82.00, U.S.$142.50. This book presents the proceedings of a symposium held in Uppsala, Sweden in 1985 and is a reprint of a publication in Hydrobiologia, Vol. 170, 1988. Despite the rather long gestation period the contents of this multi-author book should be of interest to a wide audience. This book brings together many aspects of phosphorus in freshwater ecosystems which have reached a degree of maturity, hence are appropriate for a textbook, as distinct from those about which scientific controversy or challenge still remain. Most aspects of the phosphorus cycle are discussed and the role played by biota and sediment is emphasised. Attention is directed to the drawbacks of placing too much reliance upon generalised aspects of phosphorus recycling in freshwaters and a need to consider the details of processes which take place in particular systems. While the results of laboratory experiments may be interesting, such findings still need to be proven in the field before they are accepted. While most aspects of the chemistry and biology of phosphorus are discussed, the tendency is to
292 consider the behaviour of natural systems to the exclusion of an in-depth evaluation of polluted systems. Overall, this is an excellent text book which presents the subject in a holistic manner.
Tavistock (United Kingdom)
E.I. Hamilton
The Environmental Record in Glaciers and Ice Sheets, edited by H. Oeschger and C.C. Langway Jr, Dahlem Workshop Report PC8, John Wiley & Sons, Chichester, U.K., 1989, 400 pp. Price: £47.50. The Dahlem conferences have a unique structure. There are four conferences a year for 40 or 50 participants, by invitation only. The result of each conference is a book like this one, written while the discussion is still fresh. The participants of this workshop worked in four discussion groups of twelve members each. Each group was responsible for a specific problem: (1)How do glaciers record environmental processes and preserve information? (2)What anthropogenic impacts are recorded in glaciers? (3)How can ice core chronology be established? (4)What does the long-term ice core record tell us about global changes in the environment? Group 1 concluded that, although unambiguous translation of ice core studies is neither straightforward nor simple, the environmental record is well preserved in cold glaciers, but that more research is needed to study the atmosphere-to-snow-surface transfer functions and related processes. Group 2 deduced that the determination of a deep ice core age-scale is currently a weak point in the research. The current methods of dating ice range from numerical modelling and isotope dating to changes in chronology brought about by variations in the impurity concentrations and in situ temperature changes. Much attention was given to methods employing annual layer counting, solar and terrestrial radioactivity, comparison with sea sediment and dendrochronological records, and the Earth's orbital changes. The group agreed that there is much potential in new dating techniques based on AMS (accelerator mass spectrometry) and RIMS (resonance ionization mass spectrometry). They also concluded that annual layers should be continuously measured further back in time. Group 3 focussed their considerations on the anthropogenic records contained in ice cores. Earlier research had established that the preindustrial concentrations of CO2, CH4 and N20 are now clearly being increased by Man's activity. It was inferred that if it were not for the CO2 emission due to deforestation and the increase in fossil fuel consumption, today's atmospheric CO2 concentration would probably have remained in the 280 + 10 ppm range. It was observed that, during the past 2000 years, the reported lead concentrations in Greenland deposits show a 200-fold increase. Increasing trends in NO~ and SO~- concentrations are also evident during the past 200 years in Greenland.