SUSTAINABLE HEALTH

The concept of health as a sustainable state became part of the health lexicon in the last two decades of the twentieth century. It is related to the idea of environmental sustainability and makes explicit the notion that humans and other living creatures on earth are interdependent. If human affairs are conducted in such a way as to sustain life-supporting ecosystems in a stable state of equilibrium, then humans will survive and flourish. If, however, a local, regional, or global ecosystem is degraded beyond the point where it is sustainable, then the health and survival of humans in that ecosystem cannot be sustained. As Maurice King, a research fellow at the University of Leeds, explained, the population is then caught in a demographic trap. Without external food aid or outmigration, people in such an ecosystem will starve. Sometimes a nation, tribe, or ethnic group that is demographically trapped will attempt to fight its way out. The evidence supporting a direct causal relationship between environmental stress and violent armed conflict has been documented by Thomas Homer-Dixon. The ultimate cause of such conflict is an imbalance between the number of people and the resources that are available to sustain them.

Sometimes it is difficult to say which comes first, environmental (i.e., ecosystem) pressure or population pressure. A previously stable and sustainable ecosystem may be irretrievably changed by natural forces such as a volcanic eruption, but human activity and population pressure are the most common causes. Human activities may be unwise agricultural practices—like over-grazing a savannah with sparse rainfall, excessive irrigation that alters the soil chemistry, or destruction of food-producing land for strip mining or hydroelectric dam development—or warfare that destroys what had previously been a stable agricultural ecosystem or depletes arable land of the workforce needed to maintain it. The end result is a vicious cycle; unsustainable pressure on life-supporting ecosystems and a progressively deteriorating state of population health.

Sustainable health is often linked to sustainable population growth (or a steady-state population). In the second half of the twentieth century, some countries in Africa and South Asia experienced a rate of population growth that exceeded the capacity of regional and local ecosystems to sustain them. In the Sahel, an arid zone in northwestern Africa, a sequence of droughts and occasional flash floods led to overgrazing on a fragile savannah that was unsuitable for any form of agricultural development to begin with. As a result, the region became a desert and the people began to starve. Their predicament was eased by extensive out-migration, but even so, in the intermittent crises of severe food shortages and regional famines in which many died, they were dependent upon food aid from other parts of the world.

Human communities require several kinds of resources to survive in a healthy state. The absolute essentials are secure and safe water, food, and shelter. Other factors that help create sustainable health include peace, freedom from oppression, protection from infection, secure work, and economic stability. To achieve these states, people (especially girls and women) require the ability to control their own destiny, including their reproductive capacity and the ability to care adequately for themselves and for their dependent infants and others unable to take care of themselves. This ability in turn requires insight and understanding that are acquired through education. Literacy, therefore, is another essential prerequisite for sustainable health. Early in the twenty-first century, all these prerequisites are lacking in some parts of the world, especially in several countries in sub-Saharan Africa, where health is emphatically not sustainable. In these countries, the environment is severely stressed and is being further degraded by illjudged agricultural practices and destructive extraction of mineral resources such as diamonds, as well as a lack of concern for indigenous fauna and flora, leading to catastrophic loss of biodiversity. Increasing numbers of children and young adults are illiterate, many having spent their entire lives engaged in armed conflict. The HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome) epidemic is cutting a terrible swath through the population, creating a generation of orphans who are being raised by aging and infirm grandparents. Malaria kills more than a million people every year in Africa, mostly children. Manifestly, health is not sustainable in much of the African continent, south of the Sahara, and the situation is getting worse.

In this setting, several kinds of action are urgently required to achieve sustainable health. Violent armed conflicts must be ended, which requires peace enforcement—a stage beyond peacekeeping, which has in the past been the main focus of United Nations peacekeeping forces. Populations must be educated so they gain an understanding of their situation and what must be done to improve it. Massive public health endeavors are required to control the HIV/AIDS pandemic, to control malaria and other tropical infectious diseases, and, with almost equal urgency, to control infectious and nutritional deficiency diseases, especially among children. Agricultural and animal husbandry practices must be made compatible with the environment, the climate, the topography, and the culture. Political stability must be achieved, and the infrastructure of organized urban and rural societies (communications, banking, a legal framework, etc.) must be established. The above catalogue is incomplete, but enough has been outlined to emphasize the holistic nature of sustainable health.

In the industrial nations of Western Europe, North America, Japan, and Oceania—and those nations that are in the process of industrializing (India, Thailand, Brazil)—sustainable health is closer to being achieved, but it is threatened by forces as diverse as religious fundamentalism, which is often associated with obscurantism (opposition to the spread of knowledge), and the subversion of democratic institutions by special interest groups. The gap between rich and poor grows ever wider; and while good health may be sustainable among those who are well off enough to afford good housing and medical care, the increasing proportion of people who are not economically secure face enormous obstacles to good health. In Eastern Europe and the former Soviet Union, some industrial environments are, as C. Hertzman has shown, a grave danger to health, especially women's reproductive health and child health. If the dire predictions of the Intergovernmental Panel on Climate Change are correct, the entire earth is in a precarious state that puts in doubt the long-term sustainability of all life.

John M. Last

(see also: Carrying Capacity; Climate Change and Human Health; Economics of Health; Ecosystems; Environmental Determinants of Health; Famine; Health; Health Maintenance; Inequalities in Health; War )

Bibliography

Hertzman, C. (1995). Environment and Health in Central and Eastern Europe; A Report for the Environmental Action Programme for Central and Eastern Europe. Washington, DC: World Bank.

Homer-Dixon, T. F.; Boutwell, J. H.; and Rathjens, G. W. (1993). "Environmental Stress and Violent Conflict." Scientific American 268:38–45.

King, M. (1990). "Health as a Sustainable State." Lancet 336:664–667.

McMichael, A. J.; Haines, A.; and Kovats, S. (1996). Climate Change and Human Health. Geneva: World Health Organization.