The American Council on Science and Health (ACSH) recently completed two studies in which experts evaluated environmental health sections of textbooks. Below are summaries of each study's findings.
The First Study
The first study, published in the November/December 1998 issue of the Journal of Health Education, featured evaluations of sections on the environment in five high school health text-books* published during the period 1991-1997. Seven members of ACSH's advisory board reviewed each of the six sections and responded to items in a rating form developed by ACSH staffers. This form elicited: (a) responses to questions concerning such factors as accuracy, balance, and approach to risk communication; (b) overall grading of each section; and (c) explanatory and other comments.
The seven ACSH scientific advisors noted more weaknesses in the sections than strengths. For each section at least one advisor noted:
* factual errors, unjustified assertions, or a misuse of numbers;
* biased or unbalanced treatment; and
* oversimplification or a lack of pertinent information (for example, failure to quantify chemical exposures described as toxic).
In five of the six sections reviewed, at least one advisor noted problems of exaggeration or alarmism. Environmental health subjects that at least one advisor described as poorly handled in at least four of the six relevant chapters include:
* radiation, radioactive wastes, or nuclear power;
* chlorofluorocarbons and stratospheric ozone;
* air pollution;
* water pollution; and
* recycling.
In a 1998 issue of the HPS Newsletter, published by the Health Physics Society, one of the ACSH reviewers, Dade W. Moeller, Ph.D., listed 17 examples of misinformation on radiation in the textbooks.
On average, ACSH reviewers gave the relevant sections a grade of "C" ("fair"). In half the instances of advisors responding to the statement "I recommend that this section be used in teaching high school students," either strong or moderate disagreement with the statement was indi-cated; in only 39 percent of the instances did the advisors indicate strong or moderate agreement.
ACSH recommended that professional associations that focus on health education in schools hold scientific forums on how to improve environmental health reportage. ACSH further suggested that the publishers of textbooks covering environmental health improve prepublication peer review of such chapters.
In January 1999 ACSH's president, Dr. Elizabeth M. Whelan, appeared on Fox News Television's "The Fox Report" during a feature story on ACSH's textbook study. Dr. Whelan suggested that among the relevant chapters' problems was that they conveyed scientifically unjustified popular "wisdom." She cited the omission of indispensable information in three chapters' discussions of Love Canal: the absence of scientific evidence connecting waste chemicals at Love Canal and the ailments in question.
The Second Study
The second study featured evaluations of health reportage in two environmental science textbooks. One the second edition of Environmental Science: Ecology and Human Impact (Addison-Wesley, 1996) evidently had been designed as a high school textbook. The other the fifth edition of Environmental Science: The Way the World Works (Prentice Hall, 1996) evidently had been designed as a college textbook, but its publisher had represented it to ACSH as a high school text. Seven chapters in the Addison-Wesley book and nine chapters in the Prentice Hall book addressed public health concerns.
Five of the six scientific advisors to whom ACSH staffers sent copies of relevant sections completed and returned an evaluation form (the same as had been used in the previous study).
On average, the ACSH reviewers gave the relevant sections in the Addison-Wesley book a grade of "C" (1.9 out of 4) and those in the Prentice Hall book a grade of "B-" (2.7 out of 4). In both books they noted factual errors, exaggerations, evidence of bias, and instances of advocacy.
Some of the evidence of bias was subtle. For example, one advisor noted that in the Prentice Hall book pesticides were called "biocides"** an act he described as "pejorative and unnecessary." Regarding the same book, an advisor remarked: "To equate smoking and air pollution as causes of emphysema is stupid." Reviewers also noted errors of omission. The Addison-Wesley book's chapter on radioactive waste, noted an advisor, omitted that the design of the nuclear reactor in the Chernobyl disaster is not used in the United States.
Advisor Michael Gough, Ph.D., who during the evaluation was the Cato Institute's Director of Science and Risk Studies, described the relevant chapters in Environmental Science: Ecology and Human Impact as "not very good." He stated that the chapters:
* somehow convey "the idea that everything new is bad";
* except in one instance, give "no credit . . . for things getting better";
* omit that modern agriculture, which produces more food per acre, is the only way to save wildernesses; and
* "[buy] into every cancer scare."
That the authors of these two textbooks represented protecting the environment as essential to the health of the public is commendable. The authors neglected, however, distinguishing important environmental health hazards from those that are minor, improbable, or purely conjectural.
William M. London, Ed.D., M.P.H., the former Director of Public Health of the American Council on Science and Health, served as the coordinator of the studies described in this article.
Editor's note: It is fitting to wonder how many budding environmentalists have been pointed to irrational extremism by misinformation and disinformation in books they were enjoined to study.
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*Glencoe Health: A Guide to Wellness (1996), Health: A Wellness Approach (1991), Health Skills for Wellness (1997), Holt Health (1994), and Perspectives on Health (1994)
**Editor's note: "Biocide" refers to any substance, particularly a chemical, destructive to living organisms, especially one that is toxic to many different organisms. The word, which is not commonly used, typically denotes substances that can kill both undesirable and desirable organisms ranging from insects to humans.
(From Priorities, Vol. 11, No. 4)