ENVIRONMENTAL RESEARCH 59, 114--124 (1992)
Environmental Health in the Journals ROBERT J. M C C U N N E Y , REID BOSWELL, AND JOSEPH HARZBECKER
Boston University Medical Center, Occupational Health Program, 88 E. Newton Street, Boston, Massachusetts 02118 Received May 15, 1992 The environmental health aspects of general medical practice have attracted the attention of many professional organizations in the past few years, including the American College of Physicians, the Institute of Medicine, and the American College of Occupational Medicine. To assess the degree of emphasis placed on environmental health issues in professional journals, a survey of representative speciality and general medical journals was conducted through a Medline literature search. Over the past 15-year period (1976--1990) speciality journals demonstrated a dramatic and consistent increase in published articles that were indexed under the headings environmental pollution, environmental pollutants, and environmental cancer. General medical journals also demonstrated continued increases in the rate of published articles addressing these environmental health topics. Within the environmental categories, air pollution, especially that due to dusts, was the most heavily indexed topic, followed by water pollution, especially that due to chemical contamination. This study supports the notion that environmental health issues are assuming more importance in general medical practice, especially within the speciality of occupational medicine. © 1992 Academic Press, Inc.
iNTRODUCTION Within the past decade, considerable interest in the environmental health aspects of medical practice has been demonstrated by a number of professional organizations including the American College of Occupational and Environmental Medicine (Ducatman et al., 1990), the American College of Physicians (American College of Physicians, 1990), and the Institute of Medicine (Institute of Medicine, 1988). This special issue of Environmental Research has prompted a review of the attention that environmental health topics have received in general medical and speciality journals indexed by the Medline system. Previous work has evaluated the influence of certain general medical journals (Garfield, 1986) and another paper has addressed the subjects indexed by Journal Citation Reports in occupational and general medical journals (McCunney and Harzbecker, 1992). The intent of this paper was to review both selected general medical journals as well as the traditional occupational environmental medical journals to determine the emphasis placed on environmental health topics over the past 15 years. Such a review was anticipated to shed light on certain environmental topics of academic and clinical interest as well as to show trends. Since articles published in peer review journals are likely to reflect both the research and clinical challenges of a specialty, this review was intended to indicate the environmental health topics most likely to attract the interests of practitioners and research scientists in the field. 114 0013-9351/92 $5.00 Copyright© 1992by AcademicPress, [no, All rightsof reproductionin any formreserved.
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METHODS
A. Environmental Topics Three major topics of environmental research were crossed by year from 1975 to 1990 with each of five general medical journals and six occupational specialty journals, using a Medline CD-Plus system (Section IIB, Journals). Two of the three environmental topics are listed as headings in the MeSH vocabulary file: environmental pollution (G3.850.460) and environmental pollutants (D5.284). The third topic, "environmental cancer," is not a medical subject heading. Because environmentally related cancer is such an important area of research, we decided to "create" a search set using Medline. We combined the two major cancer-related headings, "neoplasms" or "carcinogens," and crossed them with all articles in the following MeSH categories: "environment," "environmental pollutants," "environmental exposure," "environmental health," "environmental carcinogens," "occupational exposure," and "occupational diseases." We also included all articles with "environment" or "environmental" in the title of the article. Although this approach may be considered arbitrary, most articles in which environmentally related cancer is the focus of the article will have been included. Because we performed our search on a user-friendly CD-ROM system, we chose not to use a full cancer "hedge." Although creating such a hedge would have been comprehensive and interesting in searching articles related to environmental cancer, this technique was beyond the scope of the study. Our "environmental cancer" search seemed adequate to evaluate trends in the emphasis that the journals showed toward this issue over the past 15 years.
B. Journals The five general medical journals used in the study are: New England Journal of Medicine; JAMA; Lancet; Annals of Internal Medicine; and British Medical Journal. These journals were selected because of a previous article showing these journals to have the greatest "impact" (Garfield, 1986); they were also used in a previous article examining the influence of occupational medicine on general medical practice (McCunney and Harzbecker, 1992). Note that the British Medical Journal was published through 1980, at which time it was superseded by British Medical Journal--Clinical Research. In 1988, BMJ resumed publication, and British Medical Journal--Clinical Research was phased out. The year 1988 includes articles from both BMJ and British Medical Journal--Clinical Research. Throughout the study period, all of these journal articles were ascribed to the British Medical Journal. The six occupational specialty journals used in the search are: American Journal of Industrial Medicine; British Journal of Industrial Medicine; Scandinavian Journal of Work, Environment, and Health; International Archives of Occupational and Environmental Health; Journal of Occupational Medicine; and Archives of Environmental Health. These journals were also used in the article examining the influence of occupational medicine on general medical practice (McCunney and Harzbecker, 1992). The American Journal of Industrial Medicine
116
MCCUNNEY, BOSWELL, AND HARZBECKER
did not begin publication until 1980, and therefore, no articles are available between 1975 and 1979. C. Literature Search
Each of the environmental topics (pollution, pollutants, and cancer) was crossed by year (1975 through 1990) with each of the five general medical journals and the six occupational specialty journals. In each case, the topic was "exploded" to include all related or relevant terms. The articles include all material indexed through MESH: original articles, review articles, editorials, letters, and technical communications. Subject terms were restricted to major descriptors in each case. An environmental article rate was obtained by dividing the number of environmental articles by the total number of articles published by each journal. A total rate for the general medical journals was obtained by tabulating all of the environmentally related articles in the five journals by year and dividing this figure by the total number of articles published by the journals. The same method was used for the specialty journals. The environmental MeSH terms were then broken into subcategories according to the MeSH tree structure; these subcategories were crossed with each journal for the years 1987-1990. This method was used to assess the type of articles addressed under the environmental categories (Tables 1-3). Since "environmental cancer" is not a MeSH heading, we created subcategoties by combining "neoplasms" or "carcinogens" and crossed this set with each of the following terms: "environmental exposure," "environmental pollution," "environmental pollutants," and "occupational diseases." All of the subcategories were crossed with each journal for the current Medline segment on the CD-Plus Medbase system (1987 through a portion of 1991). The total percentage of the general medical journals and specialty journals under each subcategory was calculated by dividing the total number of subcategory articles by the total number of articles published under the subcategory. D. Statistical Analysis
General medical journals and specialty journals were compared on the yearly percentage of articles devoted to environmental topics through the t test. Analysis of trends in these percentages over time was carried out through regression analysis. Separate regressions were performed for each of the two types of journals. Polynomial regression was used to check for quadratic trends in the data over time. Where no significant (P < 0.05) quadratic trend was found, the data were described through a linear model. The slope of the regression line provides an estimate of the average yearly increase in the percent of articles on an environmental topic. A t test based on the regression was used to compare slopes from the two types of journals. III. R E S U L T S
Specialty journals devoted a significantly greater percentage of their articles to all three of the categories examined (Figs. 1-4). In fact, significant increases in
E N V I R O N M E N T A L HEALTH IN THE JOURNALS
117
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Environmental Health in the Journals ROBERT J. M C C U N N E Y , REID BOSWELL, AND JOSEPH HARZBECKER
Boston University Medical Center, Occupational Health Program, 88 E. Newton Street, Boston, Massachusetts 02118 Received May 15, 1992 The environmental health aspects of general medical practice have attracted the attention of many professional organizations in the past few years, including the American College of Physicians, the Institute of Medicine, and the American College of Occupational Medicine. To assess the degree of emphasis placed on environmental health issues in professional journals, a survey of representative speciality and general medical journals was conducted through a Medline literature search. Over the past 15-year period (1976--1990) speciality journals demonstrated a dramatic and consistent increase in published articles that were indexed under the headings environmental pollution, environmental pollutants, and environmental cancer. General medical journals also demonstrated continued increases in the rate of published articles addressing these environmental health topics. Within the environmental categories, air pollution, especially that due to dusts, was the most heavily indexed topic, followed by water pollution, especially that due to chemical contamination. This study supports the notion that environmental health issues are assuming more importance in general medical practice, especially within the speciality of occupational medicine. © 1992 Academic Press, Inc.
iNTRODUCTION Within the past decade, considerable interest in the environmental health aspects of medical practice has been demonstrated by a number of professional organizations including the American College of Occupational and Environmental Medicine (Ducatman et al., 1990), the American College of Physicians (American College of Physicians, 1990), and the Institute of Medicine (Institute of Medicine, 1988). This special issue of Environmental Research has prompted a review of the attention that environmental health topics have received in general medical and speciality journals indexed by the Medline system. Previous work has evaluated the influence of certain general medical journals (Garfield, 1986) and another paper has addressed the subjects indexed by Journal Citation Reports in occupational and general medical journals (McCunney and Harzbecker, 1992). The intent of this paper was to review both selected general medical journals as well as the traditional occupational environmental medical journals to determine the emphasis placed on environmental health topics over the past 15 years. Such a review was anticipated to shed light on certain environmental topics of academic and clinical interest as well as to show trends. Since articles published in peer review journals are likely to reflect both the research and clinical challenges of a specialty, this review was intended to indicate the environmental health topics most likely to attract the interests of practitioners and research scientists in the field. 114 0013-9351/92 $5.00 Copyright© 1992by AcademicPress, [no, All rightsof reproductionin any formreserved.
E N V I R O N M E N T A L H E A L T H IN T H E J O U R N A L S
115
METHODS
A. Environmental Topics Three major topics of environmental research were crossed by year from 1975 to 1990 with each of five general medical journals and six occupational specialty journals, using a Medline CD-Plus system (Section IIB, Journals). Two of the three environmental topics are listed as headings in the MeSH vocabulary file: environmental pollution (G3.850.460) and environmental pollutants (D5.284). The third topic, "environmental cancer," is not a medical subject heading. Because environmentally related cancer is such an important area of research, we decided to "create" a search set using Medline. We combined the two major cancer-related headings, "neoplasms" or "carcinogens," and crossed them with all articles in the following MeSH categories: "environment," "environmental pollutants," "environmental exposure," "environmental health," "environmental carcinogens," "occupational exposure," and "occupational diseases." We also included all articles with "environment" or "environmental" in the title of the article. Although this approach may be considered arbitrary, most articles in which environmentally related cancer is the focus of the article will have been included. Because we performed our search on a user-friendly CD-ROM system, we chose not to use a full cancer "hedge." Although creating such a hedge would have been comprehensive and interesting in searching articles related to environmental cancer, this technique was beyond the scope of the study. Our "environmental cancer" search seemed adequate to evaluate trends in the emphasis that the journals showed toward this issue over the past 15 years.
B. Journals The five general medical journals used in the study are: New England Journal of Medicine; JAMA; Lancet; Annals of Internal Medicine; and British Medical Journal. These journals were selected because of a previous article showing these journals to have the greatest "impact" (Garfield, 1986); they were also used in a previous article examining the influence of occupational medicine on general medical practice (McCunney and Harzbecker, 1992). Note that the British Medical Journal was published through 1980, at which time it was superseded by British Medical Journal--Clinical Research. In 1988, BMJ resumed publication, and British Medical Journal--Clinical Research was phased out. The year 1988 includes articles from both BMJ and British Medical Journal--Clinical Research. Throughout the study period, all of these journal articles were ascribed to the British Medical Journal. The six occupational specialty journals used in the search are: American Journal of Industrial Medicine; British Journal of Industrial Medicine; Scandinavian Journal of Work, Environment, and Health; International Archives of Occupational and Environmental Health; Journal of Occupational Medicine; and Archives of Environmental Health. These journals were also used in the article examining the influence of occupational medicine on general medical practice (McCunney and Harzbecker, 1992). The American Journal of Industrial Medicine
116
MCCUNNEY, BOSWELL, AND HARZBECKER
did not begin publication until 1980, and therefore, no articles are available between 1975 and 1979. C. Literature Search
Each of the environmental topics (pollution, pollutants, and cancer) was crossed by year (1975 through 1990) with each of the five general medical journals and the six occupational specialty journals. In each case, the topic was "exploded" to include all related or relevant terms. The articles include all material indexed through MESH: original articles, review articles, editorials, letters, and technical communications. Subject terms were restricted to major descriptors in each case. An environmental article rate was obtained by dividing the number of environmental articles by the total number of articles published by each journal. A total rate for the general medical journals was obtained by tabulating all of the environmentally related articles in the five journals by year and dividing this figure by the total number of articles published by the journals. The same method was used for the specialty journals. The environmental MeSH terms were then broken into subcategories according to the MeSH tree structure; these subcategories were crossed with each journal for the years 1987-1990. This method was used to assess the type of articles addressed under the environmental categories (Tables 1-3). Since "environmental cancer" is not a MeSH heading, we created subcategoties by combining "neoplasms" or "carcinogens" and crossed this set with each of the following terms: "environmental exposure," "environmental pollution," "environmental pollutants," and "occupational diseases." All of the subcategories were crossed with each journal for the current Medline segment on the CD-Plus Medbase system (1987 through a portion of 1991). The total percentage of the general medical journals and specialty journals under each subcategory was calculated by dividing the total number of subcategory articles by the total number of articles published under the subcategory. D. Statistical Analysis
General medical journals and specialty journals were compared on the yearly percentage of articles devoted to environmental topics through the t test. Analysis of trends in these percentages over time was carried out through regression analysis. Separate regressions were performed for each of the two types of journals. Polynomial regression was used to check for quadratic trends in the data over time. Where no significant (P < 0.05) quadratic trend was found, the data were described through a linear model. The slope of the regression line provides an estimate of the average yearly increase in the percent of articles on an environmental topic. A t test based on the regression was used to compare slopes from the two types of journals. III. R E S U L T S
Specialty journals devoted a significantly greater percentage of their articles to all three of the categories examined (Figs. 1-4). In fact, significant increases in
E N V I R O N M E N T A L HEALTH IN THE JOURNALS
117
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