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Colin Baird. W. H. Freeman: New York, 1995, xix + 484 pp. Figs. and tables. 18.8 x 24 cm.
Written for students with an introductory chemistry background, Colin Baird's new text does a superb job in covering environmental chemistry while also building on chemical principles developed in earlier course work. This book is truly written from a chemist's perspective. Baird defines environmental chemistry as "being concerned with the chemical aspects of problems that human beings have created in the natural environment".
The text focuses on four major areas: atmospheric chemistry (three chapters on stratospheric chemistry, tropospheric chemistry, and global warming), toxic organic substances (an organic chemistry overview and a 71-page chapter on toxic organic chemicals), water chemistry and concerns (three chapters on contamination and purification, acid-base chemistry of the carbonate system, and heavy metals/soil chemistry), and energy (one chapter on energy production and its
environmental consequences).
Indicative of the thoroughness of the text is the first chapter (after the introduction) on stratospheric
chemistry. The author covers photochemistry, ozone production, noncatalytic and catalytic ozone destruction, Lewis structure of free radicals, heterogeneous-driven Antarctic ozone depletion, CFCs, CFC replacements, and international agreements. It ends with a summary of principles that govern stratospheric processes. Students found this effective, since it condensed the many reactions into the coherent framework of principles that tied the subject together.
Baird incorporates inset boxed sections to focus on related areas. The stratospheric chemistry chapter
examines Lewis structures of free radicals, rates of free radical reactions, formulas and codes for carbon
compounds (including CFCs), supersonic aircraft and ozone depletion, and recent research on ozone destruction. The kinetics discussion links reaction rates to enthalpy changes. Endothermic reactions necessarily have activation energies at least as large as their endothermicity and thus occur slowly (since a characteristic of these reactions is that activation energy exceeds the endothermicity by a small amount).
Correspondingly, exothermic reactions have large rate constants. The chapter summary identifies relative bond strengths for stratospheric species containing loosely bound oxygen atoms. Students thus have the tools to predict enthalpy changes and relative rate constants for many important stratospheric reactions.
At times, Baird devotes the first half of a chapter to a discipline overview, followed by more detailed
discussions. For example, the tropospheric chemistry chapter introduces acid rain, photochemical smog,
particulates, indoor air pollution, and outdoor air pollution. The last half spirals back to examine reactivity principles, methane oxidation mechanisms, photochemical smog formation mechanisms, and acid rain formation (both homogeneous gas phase and aqueous phase oxidation of sulfur dioxide) mechanisms. Students found this approach effective in better understanding the context in which specific mechanisms have importance.
Baird does not assume students have completed organic chemistry; he devotes one chapter to organic
fundamentals. This is directly followed by an extensive chapter on toxic organic chemicals. This section
alone is well worth the price of the book. Topics include pesticides, organochlorine insecticides (DDT and analogs, toxaphenes, chlorinated cyclopentadienes), organophosphate and carbamate insecticides, natural insecticides, herbicides (triazines, paraquat, phenoxy), dioxin contamination of herbicides and preservatives, dioxin sources, PCBs (structure, properties, uses) furan contamination, toxicology of PCBs dioxins, and furans, and finally PAHs. Baird traces the evolution of pesticide structure as well as the specific physiological effects. This historical and biochemical perspective provides the necessary background to readily understand environmental research involving anthropogenic organics in the environment.
Baird addresses quantitative concepts in a chapter on the acid-base chemistry of the carbonate system.
The carbon dioxide/water and carbonate/bicarbonate equilibria are examined separately and then together. The final system involves Henry's law, weak acid equilibria, weak base equilibria, and solubility equilibria.
Combined equilibria calculations are surprisingly close (in spite of not using activities) to the calcium and bicarbonate concentrations commonly observed in calcareous regions. This chapter provides an exceptional opportunity for students to integrate many of the concepts covered in the latter half of general chemistry. The results provide insights into the underlying chemical basis for the main ionic constituents of natural waters.
For a first edition, the text has few errorsBaird and the reviewers have done meticulous work. Each chapter has quantitative exercises for students within sections. End-of-chapter problems are nonquantitative and can be answered by referring back to the appropriate paragraph. It would be nice to see more quantitative problems in each chapter's problem set (including several that involve spreadsheets).
The book is extremely readableits clarity received the highest student ratings I have ever seen. This
provided time in class to examine related issues, since there is less need to explain what is already discussed so well. One distraction was the author's use of the Beer-Lambert equation in a form different from the
convention used in analytical courses.
Overall the selection of topics is exceptional. After covering the entire text in a semester, student
feedback indicated that all topics covered were relevant and important. I found that all lessons involved issues I had routinely encountered in the environmental field. While toxocology is indirectly discussed a number of times; there is, unfortunately, no separate section on toxicology to discuss principles such as dose-response curves, toxicological testing, routes of entry, epidemiology, and determination of health limits.
If ever a case could be made for requiring majors to complete environmental chemistry, Baird's selection of environmental topics represents a compelling argument. The fundamentals so eloquently discussed are ideas that all graduates should well understand.
This is a book hitting on all cylinders. Every so often, you find a text ideally organized and artistically put together to fit a discipline particularly well-I believe the two that best match this description are Dan Harris's Quantitative Analysis, and Colin Baird's Environmental Chemistry. The latter is certainly a winner that I highly recommend, particularly for those developing a new course in environmental chemistry.
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