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GUEST EDITORIAL
On reviewing environmental models Since the turn of the century scientific progress has gone hand-in-hand with the evolution of a subtle and effective review system in which reports of original work are subjected to anonymous criticism by peer reviewers prior to publication. This system, as followed by Environmental Science & Technology and steered by its editorial staff, is fair, vigilant, and successful. It depends heavily on the goodwill of reviewers who voluntarily devote time to the process for the collective benefit of the entire environmental science community. Most research reports can be judged by a thorough reading-looking for appropriate techniques and reasonable results-and a check of the mathematics and statistics. However, environmental science and management rely increasingly on complex models to describe, for example, the complex behavior of chemicals in a multimedia environment, routes to human exposure, spill damages, atmospheric dispersion in complex terrain, or extensive ionic equilibria. The intellectual contribution is often the selection and assembly of equations and parameter values of a lengthy computer program. Few reviewers are likely to check the coding line by line to detect mistakes. Normally all that can be accomplished is a cursory check of reasonableness and a comment on the assumptions used. How can we ensure that such models are valid, free from mistakes, and thus reliable tools in the hands of scientists and managers? Perhaps there are two ways. Agencies that fund the development of models should also accept the obligation to fund thorough, impartial, time-consuming, and thus expensive peer reviews. Such reviews require allocation of time and money-more than even the persuasive ES&Treviewing staff can hope to achieve. Second, agencies and professional societies could sponsor “round robins’’ (so deservedly popular in analytical chemistry) in which the same modeling task is addressed by independent groups who can then come together to compare and criticize approaches and
116 Environ. Sci. Technol.. W. 22, NO.2. 1988
results in detail. Recently the International Joint Commission sponsored an event of this type, in which three groups (from Manhattan College, Limno-Tech Inc. of Ann Arbor, and the University of Toronto) compiled rival models of PCB behavior in Lake Ontario over the period 1940-2000. The models were then compared and criticized during a two-day intensive session. Fortunately they gave similar results despite quite substantial differences in approach. No doubt the better features of each model will become incorporated into the others. More confidence is established that the models are faithfully describing the same environmental reality. Mistakes should be exposed and eliminated. A free market is encouraged in which the best models will evolve and flourish. The science of describing complex environmental phenonema is advanced. Complex, computer-based models can play an important role in environmental science, but we cannot expect the existing review system to give them the scrutiny they need and deserve. Those who fund, develop, and ultimately use models must be willing to seek, encourage, and sponsor novel peer reviewing a p proaches to ensure the scientific rigor of the published word, which is at the core of scientific progress.
Don Mac& is a professor of chemical engineering and applied chemistry at the Universiiy of Toronto. His research interests include the environmentalfate and transport of toxic substances with a special emphasis on modeling. the volatizarion of organic compoundsfrom water, and the measurement of physical and chemical properties. He hos been a member of the ES&T Editorial Advisory ~~
Board since 1984.
W13936XIW09224116501.50lO 0 1988 American Chemical Society
