Annual Review of Public Health - Volume 29, 2008

The global motor vehicle population has grown very rapidly in the past half century and is expected to continue to grow rapidly for the next several decades, especially in developing countries. As a result, vehicles are a major source of urban air pollution in many cities and are the fastest-growing source of greenhouse emissions. Strategies exist to reduce both problems, but many countries emphasize one over the other rather than pursuing strategies that reduce both concerns. Using diesel as an example, this article illustrates that it is now possible not only to reduce carbon dioxide with the increased use of diesel vehicles but also to improve urban air pollution. Doing so requires both stringent emissions regulations and clean fuels. Several principles contained in the Bellagio Memorandum are highlighted as guides for policy makers.

Interventions in the energy sector offer significant opportunities for reducing both greenhouse and other health-damaging pollution, resulting in what are called “co-benefits.” The health community plays a critical role in evaluating such interventions to optimize progress of both sorts because both affect health. In detail, analyses require sophisticated modeling and specific local information. As a starting point, however, we offer here a set of scoping methods for obtaining a quick assessment of these co-benefits for interventions in the energy sector, the arena with the highest potential for significant co-benefits. Thus we combine relevant methods developed separately in recent years for cost-effectiveness assessments in the climate change, health, and development communities. We offer sample calculations, which illustrate the apparent high degree of co-benefit effectiveness for targeted interventions in the household energy sector in developing countries.

Climate change is projected to have adverse impacts on public health. Cobenefits may be possible from more upstream mitigation of greenhouse gases causing climate change. To help measure such cobenefits alongside averted disease-specific risks, a health impact assessment (HIA) framework can more comprehensively serve as a decision support tool. HIA also considers health equity, clearly part of the climate change problem. New choices for energy must be made carefully considering such effects as additional pressure on the world's forests through large-scale expansion of soybean and oil palm plantations, leading to forest clearing, biodiversity loss and disease emergence, expulsion of subsistence farmers, and potential increases in food prices and emissions of carbon dioxide to the atmosphere. Investigators must consider the full range of policy options, supported by more comprehensive, flexible, and transparent assessment methods.

Heat is an environmental and occupational hazard. The prevention of deaths in the community caused by extreme high temperatures (heat waves) is now an issue of public health concern. The risk of heat-related mortality increases with natural aging, but persons with particular social and/or physical vulnerability are also at risk. Important differences in vulnerability exist between populations, depending on climate, culture, infrastructure (housing), and other factors. Public health measures include health promotion and heat wave warning systems, but the effectiveness of acute measures in response to heat waves has not yet been formally evaluated. Climate change will increase the frequency and the intensity of heat waves, and a range of measures, including improvements to housing, management of chronic diseases, and institutional care of the elderly and the vulnerable, will need to be developed to reduce health impacts.

In society's effort to address and prepare for climate change, the health community itself must ensure that it is prepared. Health personnel will require flexible and iterative action plans to address climate change at the individual, hospital, local health department, state, and national levels. This requires that health workers analyze the impact of climate change with a view to human health, and then formulate robust policy and demonstrate authentic leadership. In this review, we summarize the status of the health community's preparation for climate change and provide specific recommendations for action at each level. Although preparation status and recommendations vary, our observation is that it is not enough for public health and medical care agencies and departments to develop policies and advocate change. They have a direct responsibility to demonstrate substantive leadership.

Ecologic studies use data aggregated over groups rather than data on individuals. Such studies are popular because they use existing databases and can offer large exposure variation if the data arise from broad geographical areas. Unfortunately, the aggregation of data that define ecologic studies results in an information loss that can lead to ecologic bias. Specifically, ecologic bias arises from the inability of ecologic data to characterize within-area variability in exposures and confounders. We describe in detail particular forms of ecologic bias so that their potential impact on any particular study may be assessed. The only way to overcome such bias, while avoiding uncheckable assumptions concerning the missing information, is to supplement the ecologic with individual-level information, and we outline a number of proposals that may achieve this aim.

As U.S. life expectancy has increased, questions arise as to how the quality of health and functioning in the elderly population has changed. Data from the 1982–2004 National Long-Term Care Survey (NLTCS) suggested that chronic disability prevalence above age 65 declined at an increasing rate with a 2.2% per annum rate of decline from 1999 to 2004 (71). Inflation-adjusted per capita Medicare expenditure rates in nondisabled persons also declined, 0.9% per annum from 1982 to 2004, which suggests that declines in disability were driven by improving health—not by increases in per capita health expenditures. Declines in disability prevalence were found in other U.S. national health surveys. Analyses of U.S. Civil War veterans suggest recent disability declines were continuations of declines in both chronic disease and disability occurring over the past century due to improved nutrition, sanitation, and education. Concerns exist about whether disability declines will continue because of recent increases in obesity prevalence.

Data are reviewed on the descriptive epidemiology of commonly occurring DSM-IV mental disorders in the United States. These disorders are highly prevalent: Roughly half the population meets criteria for one or more such disorders in their lifetimes, and roughly one fourth of the population meets criteria in any given year. Most people with a history of mental disorder had first onsets in childhood or adolescence. Later onsets typically involve comorbid disorders. Some anxiety disorders (phobias, separation anxiety disorder) and impulse-control disorders have the earliest age of onset distributions. Other anxiety disorders (panic disorder, generalized anxiety disorder, post-traumatic stress disorder), mood disorders, and substance disorders typically have later ages of onset. Given that most seriously impairing and persistent adult mental disorders are associated with child-adolescent onsets and high comorbidity, increased efforts are needed to study the public health implications of early detection and treatment of initially mild and currently largely untreated child-adolescent disorders.

The Women's Health Initiative (WHI) was initiated in 1992 as a major disease-prevention research program among postmenopausal women. The program includes a randomized controlled intervention trial involving 68,132 women and four distinct interventions: conjugated equine estrogens, alone or in combination with medroxyprogesterone acetate, for coronary heart disease prevention with breast cancer as an anticipated adverse effect; a low-fat eating pattern for breast and colorectal cancer prevention; and calcium and vitamin D supplementation for hip fracture prevention. Results from this multifaceted trial have made a substantial impact in clinical practice. A companion cohort study among 93,676 women serves as a source for new risk factor information and provides a comparative observational assessment of the clinical trial interventions. A specimen repository and quality-controlled outcome data for a range of diseases are among the resources that support the ongoing research program. WHI clinical trial contributions and challenges are reviewed and discussed.

Antimicrobial resistance is a major public health crisis, eroding the discovery of antimicrobials and their application to clinical medicine. There is a general lack of knowledge of the importance of agricultural antimicrobial use as a factor in antimicrobial resistance even among experts in medicine and public health. This review focuses on agricultural antimicrobial drug use as a major driver of antimicrobial resistance worldwide for four reasons: It is the largest use of antimicrobials worldwide; much of the use of antimicrobials in agriculture results in subtherapeutic exposures of bacteria; drugs of every important clinical class are utilized in agriculture; and human populations are exposed to antimicrobial-resistant pathogens via consumption of animal products as well as through widespread release into the environment.

Over the past quarter century, primarily as a result of scientific discovery, citizen advocacy, and legislative action, comprehensive clean indoor air laws have spread rapidly throughout the world. Laws that establish completely smoke-free indoor environments have many relative advantages including being low cost, safe, effective, and easy to implement. The diffusion of these laws has been associated with a dramatic and rapid reduction in population levels of serum cotinine among nonsmokers and has also contributed to a reduction in overall cigarette consumption among smokers, with no adverse economic impact, except to the tobacco industry. Currently, nearly half of the U.S. population lives in jurisdictions with some combination of completely smoke-free workplaces, restaurants, or bars. The diffusion of clean indoor air laws is spreading rapidly throughout the world, stimulated by the first global health treaty, the Framework Convention on Tobacco Control.

The public health impact of aflatoxin exposure is pervasive in economically developing countries; consequently, we need to design intervention strategies for prevention that are practicable for these high-risk populations. The adverse health consequences of aflatoxins in populations are quite varied, eliciting acute effects, such as rapid death, and chronic outcomes, such as hepatocellular carcinoma. Furthermore, a number of epidemiological studies describe a variety of general adverse health effects associated with aflatoxin, such as impaired growth in children. Thus, the magnitude of the problem is disseminated across the entire spectrum of age, gender, and health status in the population. The aflatoxins multiplicatively increase the risk of liver cancer in people chronically infected with hepatitis B virus (HBV), which illustrates the deleterious impact that even low toxin levels in the diet can pose for human health. Thus other aflatoxin interactions, which likely contribute to the diesease burden, still remain to be identified. Therefore, many diverse and appropriate strategies for disease prevention are needed to decrease the incidence of aflatoxin carcinogenesis in developing countries.

Post-9/11, preparedness planning has catalyzed intrastate regionalization of local public health resources throughout the United States. Investigating this trend unveils several regionalization themes, relevant in other sectors of government, which are applicable to local public health. In this review article, we begin by briefly examining the lessons learned from regionalization for police and fire services, drawing comparisons to public health. Then we provide a brief history of the accelerating regionalization of local public health services sparked by the current attention to emergency preparedness. In particular, we offer case studies from Massachusetts and the National Capital Region to highlight examples of regionalization outcomes related to networking, coordination, standardization, and centralization of public health services. The impact of social capital on preparedness is also explored. Finally, we summarize research needs for the future.

This article provides an overview of the ways in which mass communication has been used—or can be used—to promote beneficial changes in behavior among members of populations. We use an ecological perspective to examine the ways in which mass media interventions can be used to influence public behavior both directly and indirectly. Mass media interventions that seek to influence people directly—by directly targeting the people burdened by the public health problem of concern and/or the people who influence them—have a long basis in public health history, and recent reviews have clarified our expectations about what can be expected from such approaches. Mass media interventions that seek to influence people indirectly—by creating beneficial changes in the places (or environments) in which people live and work—have equal if not greater potential to promote beneficial changes in population health behaviors, but these are currently less explored options. To have the greatest possible beneficial influence on public behavior with the public health resources available, we recommend that public health program planners assess their opportunities to use media to target both people and places in a manner that complements and extends other investments being made in population health enhancement.

Eliminating health disparities is a fundamental, though not always explicit, goal of public health research and practice. There is a burgeoning literature in this area, but a number of unresolved issues remain. These include the definition of what constitutes a disparity, the relationship of different bases of disadvantage, the ability to attribute cause from association, and the establishment of the mechanisms by which social disadvantage affects biological processes that get into the body, resulting in disease. We examine current definitions and empirical research on health disparities, particularly disparities associated with race/ethnicity and socioeconomic status, and discuss data structures and analytic strategies that allow causal inference about the health impacts of these and associated factors. We show that although health is consistently worse for individuals with few resources and for blacks as compared with whites, the extent of health disparities varies by outcome, time, and geographic location within the United States. Empirical work also demonstrates the importance of a joint consideration of race/ethnicity and social class. Finally, we discuss potential pathways, including exposure to chronic stress and resulting psychosocial and physiological responses to stress, that serve as mechanisms by which social disadvantage results in health disparities.

Food and eating environments likely contribute to the increasing epidemic of obesity and chronic diseases, over and above individual factors such as knowledge, skills, and motivation. Environmental and policy interventions may be among the most effective strategies for creating population-wide improvements in eating. This review describes an ecological framework for conceptualizing the many food environments and conditions that influence food choices, with an emphasis on current knowledge regarding the home, child care, school, work site, retail store, and restaurant settings. Important issues of disparities in food access for low-income and minority groups and macrolevel issues are also reviewed. The status of measurement and evaluation of nutrition environments and the need for action to improve health are highlighted.

Obesity has risen dramatically in the past few decades. However, the relative contribution of energy intake and energy expenditure to rising obesity is not known. Moreover, the extent to which social and economic factors tip the energy balance is not well understood. This exploratory study estimates the relative contribution of increased caloric intake and reduced physical activity to obesity in developed countries using two methods of energy accounting. Results show that rising obesity is primarily the result of consuming more calories. We estimate multivariate regression models and use simulation analysis to explore technological and sociodemographic determinants of this dietary excess. Results indicate that the increase in caloric intake is associated with technological innovations as well as changing sociodemographic factors. This review offers useful insights to future research concerned with the etiology of obesity and suggests that obesity-related policies should focus on encouraging lower caloric intake.