Book Reviews

Health Promotion Planning:
An Educational and Ecological Approach (third edition)

Health Promotion Planning: An Educational and Ecological Approach is the third edition of a book that has been a core reference on health promotion planning for the past 10 years. This edition, like the others, is based on the PRECEDE-PROCEED framework. It uses an analytic approach to help planners decide what health issues to address and how to address them. This is a challenging task given the complexity of planning using the health promotion principles of community involvement and comprehensive, effective response to community needs. The book provides a specific approach with detailed steps to accomplish this task.

The framework around which the book is built starts with a social assessment of the factors influencing the quality of life of the population, followed by an epidemiologic assessment of the health issues affecting quality of life. Phase 3 is a behavioural and environmental evaluation of the factors influencing the health and health problems of the population. In Phase 4 an educational and ecological assessment is done to identify the predisposing, enabling factors influencing both behaviour and lifestyle and the environment. At this point, program priorities, targets and objectives have been identified; in Phase 5 the key administrative and policy factors are identified to assist the planner to develop programs that will have the greatest chance of success. The final four phases involve implementation and conducting evaluations of the process, impact and outcomes.

The book is organized into five sections: an overview of health promotion and the framework; a chapter on each of the five assessment planning phases; a chapter on evaluation basics; a chapter on specific applications of the planning framework in each of four settings- community, occupational, school and health care; and a final new chapter on a computer application of the framework called EMPOWER. Each chapter has exercises and a detailed list of references. The glossary at the end assists the reader to navigate through sometimes confusing terminology.

The authors take an academic, thoughtful approach to presenting the information in the book. The rationale for each step as well as the theoretical and research basis are included in each chapter. This is nicely balanced with attention to the practical realities of working in the complexities of "real life". The authors do not shy away from stating their values. Although these may not be shared by everyone, their inclusion points to the need to include a values discussion in every planning exercise.

While this book provides steps in each planning phase, it is not a simple "how to" book. It presents options for consideration by planners as they tailor their own process. This is one of the book's strengths, but readers must be prepared to exercise their own judgement and use their own experience to make the best use of it. Readers will find this book most useful as a reference to which they can turn during the course of a planning exercise. It is possible to use it starting at any of the points in the five-stage assessment process, although the authors do repeatedly emphasize that unless program decisions are grounded in meeting real community needs, they may not be effective.

The book will appeal to a wide range of individuals involved in health promotion planning. It takes a broad view of health promotion activities, from those directed at underlying determinants such as poverty to specific interventions in the health care setting. This comprehensiveness is a valuable aspect to the book because practitioners in different settings can identify both the similarities and differences in their practice. The book would be very useful for an academic course in health promotion planning at either the senior undergraduate or graduate level.

While much of the third edition has material that was available in the previous edition, there is enough new material to make it a good buy for even those who have the previous text. For example, the addition of the word "ecological" in the title is a good example of how the authors have incorporated recent thinking into this edition. The reference list includes many new references, a and it is very useful to have many of the key health promotion references listed in one place.

Overall rating:	Excellent
Strengths:	Broad approach to health promotion that reflects recent thinking in the field Uses a systematic, logical approach to planning Strong theoretical and research basis Includes evaluation as an essential component of program planning Includes examples of the use of the planning framework in "real life" situations Gives options and rationale for each planning phase to support a tailored approach
Weaknesses:	Dense nature of the text itself (so much information at such a significant depth could benefit from a larger page and font to facilitate the ease of reading) Some sections have less detail than others
Audience:	Health promotion program planners and managers; public health and community health service providers; federal, provincial/territorial, regional government health departments; non-governmental organizations; students and educators in senior undergraduate and postgraduate health programs in universities and colleges; researchers

    

Paula J Stewart
Paula J Stewart & Associates
Community Health Consultant
1093 Chablis Park
Orleans, Ontario K1C 2T5

Quantitative Estimation and Prediction of Human Cancer Risks
IARC Scientific Publications No 131

This volume from the International Agency for Research on Cancer consists of nine papers by different authors, each of which provides a discussion of an aspect of cancer risk assessment.

The relationship between exposure to risks and the development of cancer at a particular site in a human is seldom known with any degree of precision. This is so partly because understanding of the mechanics of carcinogenesis is not complete. Also, dose-response curves for most carcinogens and most human cancer sites are not well understood. Extrapolation from animal experiments using high levels of exposure to humans affected by low levels of exposure is often open to question. The synergistic effects of exposures to multiple risks are poorly understood.

Another point to be considered is the fact that long latencies are associated with most cancers, and assessing the effects of exposures in the distant past is problematic. Estimating the exposure dose of most individuals to most carcinogens is an imprecise science. Furthermore, the reasons why some humans are more susceptible than others to the development of malignant tumours at certain sites are in the early stages of study. With some notable exceptions, cigarette smoking being one, the relative risks of everyday exposures tend to be small and difficult to measure with sufficient precision to distinguish between a small effect and no effect, which adds another layer of complexity to the problem of quantifying risk effects.

Nevertheless, many carcinogens have been identified. Regulations regarding manufacturing, distribution and use of many of these substances are in place, at least in developed parts of the world. However, even though a substance is known to be a carcinogen, it will not necessarily be banned from manufacture or use. For example, it is possible for a pesticide to be implicated in causing cancer and yet still be widely used because of its value in enhancing crop yields. When deciding upon regulation of a substance, regulatory agencies must take into account economic impact as well as carcinogenic risk.

The fact that regulation, not necessarily prohibition, of carcinogens must be carried out in the face of great complexity in the exposure/outcome relationship, requires that "quantitative estimation and prediction of human cancer risks" at least be attempted. This book essentially surveys the current state of the science. The following chapter titles reveal the extent of the work reviewed in the volume.

1.  "Quantitative estimation and prediction of human cancer risk: its history and role in cancer prevention"
   
   
2. "Quantitative estimation and prediction of cancer risk: review of existing activities"
   
   
3. "Principles of the epidemiological approach to QEP" [quantitative estimation and prediction of human cancer risk]
   
   
4. "Measurement of exposure and outcome in epidemiological studies used for quantitative estimation and prediction of risk"
   
   
5. "Long- and medium-term carcinogenicity studies in animals and short-term genotoxicity tests"
   
   
6.  "Empirical approaches to risk estimation and prediction"
   
   
7. "Mechanisms of carcinogenesis and biologically based models for estimation and prediction of risk"
   
   
8. "Review of specific examples of QEP"
   
   
9. "Future perspectives, unresolved issues and research needs"

This volume shows the effects of taking considerable care in preparation and editing. Hence, without undue struggle, the reader will be able to gain an appreciation of the problems, complexity and progress associated with the various aspects of cancer risk assessment. The extensive bibliography included in each chapter will allow those with a thirst for deeper insight into quantitative estimation and prediction of human cancer risk than is provided in this admirable volume to go to the literature and slake that thirst.

Ian B MacNeill
Professor Emeritus
Department of Statistical and Actuarial Sciences
University of Western Ontario
London, Ontario N6A 5B7

Epidemiology of Childhood Cancer
IARC Scientific Publications No 149

Although childhood cancer accounts for only about 1% of all cancers in Canada and even fewer deaths, its public health importance is high, in part because of the long-term health implications for survivors. Childhood cancer differs in many ways from its adult counterpart, including site of occurrence, as well as histologic and clinical behaviour, and thus needs to be considered separately. Though there are many useful textbooks about the epidemiology of cancer, Epidemiology of Childhood Cancer is the first to synthesize and describe the various aspects of childhood cancer epidemiology in one monograph.

An overview of design issues relating to the conduct of epidemiologic studies is presented in Chapter 1, including the consideration of alternative explanations for study findings. Several current hypotheses relating to complex routes of exposure for some childhood cancer risk factors are also briefly discussed. Two examples are Greaves' hypothesis on population mixing and acute lymphocytic leukemia, and the relation of N-nitroso compounds to brain tumours.

The second chapter covers the descriptive epidemiology of childhood cancer and is organized according to the histology-based Birch and Marsden (Manchester) classification system. For each diagnostic group, geographical patterns, age-specific incidence and sex ratios, ethnic origin and time trends are described. Additionally, variation in rates according to socio-economic status as well as other spatial and temporal clustering are defined where applicable. Finally, for certain childhood cancers, distinct epidemiologic features are discussed such as skeletal subtype distribution for osteosarcomas.

Chapters 3-10 present the current knowledge of major risk factors for childhood cancer, organized by exposure rather than cancer type. Chapter 3 focuses on genetic factors and the proportion of each cancer type believed to be the consequence of specific genetic syndromes and/or familial aggregations. Unfortunately, this chapter suffers from the limitations of any text about a fast developing area, in that it is already out of date.

Chapters 4 and 5 examine particular exposures in relation to childhood cancer risk. First, the effects of ionizing radiation on childhood cancer outcomes (mostly leukemia) are discussed in Chapter 4. Specific examples of residential exposure from both point source (i.e. bombs, nuclear plant accidents) and diffuse origin (i.e. nuclear installations, background radiation) are reviewed. Then Chapter 5 provides a detailed discussion of EMF (electromagnetic field) exposure assessment as well as a review of pertinent studies.

The associations between paternal occupational and environmental exposures to chemicals and dusts are addressed in Chapter 6. Most studies have focused on the positive association with leukemia, though the few studies examining other childhood cancers are also reviewed here.

The seventh chapter discusses the hypothesis that childhood cancer risk is related to maternal and infant infection. Most of this text reviews studies on leukemia, though there are small sections on lymphoma, brain tumours and other childhood cancers. Maternal and paternal lifestyle habits and their association with cancer in the offspring are examined in the next chapter, including diet and vitamin supplements, as well as tobacco, alcohol and recreational drug use. Associations between specific types of childhood cancer and maternal age, birth order and prior reproductive history are considered in Chapter 9, while the index child's medical history in relation to cancer risk is discussed in Chapter 10.

The final Chapter 11 summarizes the evidence on risk factors for each diagnostic group according to the strength of published findings, based loosely on the Brandford-Hill criteria. The chapter contains excellent reference tables outlining the evidence for leukemias, lymphomas, central nervous system tumours, neuroblastoma and Wilms' tumour. The continuing problems of accurate and valid exposure assessment and non-biased selection of control subjects are addressed. The authors assert that objective markers of exposure need to be developed and used in more epidemiologic studies. Furthermore, adequate sample sizes for subtype analysis require the involvement of co-operative groups, and studies should be expanded to include subjects from outside North America and Europe.

This book is an excellent primer for anyone contemplating research into the epidemiology of childhood cancer. The review of etiologic studies is exhaustive and critical, though an update will need to be done shortly as the monograph only includes studies published before mid-1997. In such a quickly evolving field, especially when combined with molecular biology, regular updates are necessary. Moreover, the monograph should expand its discussion of biologic mechanisms; though mentioned in certain sections, a separate chapter may be useful. Nonetheless, Epidemiology of Childhood Cancer is an extremely thorough and well-documented reference book including clear and detailed tables and an extensive bibliography. It should be included in the library of anyone interested in childhood cancer epidemiology.

Amanda Shaw
Cancer Bureau
Laboratory Centre for Disease Control
Health Canada, Tunney's Pasture
Address Locator: 0601C1
Ottawa, Ontario K1A 0L2

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