GEO-1: Chapter 4: Looking to the Future: Human Health: Past and Present Trends

Note: This is the 1997 edition of UNEP's Global Environment Outlook. If you are interested in more recent information, please see the 2000 and 2002 editions.

United Nations Environment Programme (UNEP)

Global Environment Outlook-1 - The Web version

Chapter 4: Looking to the Future

Human Health

Past and Present Trends

Over the last four decades, there has been an enormous and continuing improvement in human health world-wide, although regional situations still vary. The main determinants of human health can be grouped as follows:

medical care (van der Velden et al., 1995; World Bank, 1993b);
water sanitation, storage, supply, and sewage systems (Cairncross and Feachem, 1983; Pollitzer, 1959; World Bank, 1993a);
education, insight, and rational behavior (McKeown, 1976; World Bank, 1993b);
economic situation and income status; and
environmental factors (such as water quality and chemical pollution).

In industrial regions, health improvements occurred at a constant pace over the last 200 years, and often determinants came in sequential order, facilitating the study of their relative influence. Medicine, for instance, did not contribute to the enormous health improvements in north-western Europe in the nineteenth century, when life expectancy increased about 20 years, but it did play a role in the gain of another 20 years during the twentieth century (through vaccination programmes and the use of antibiotics, for instance).

In currently developing regions, a multitude of health determinants have an influence at the same time. There are important negative impacts of environmental factors, as well as more positive impacts, of which economic situation and family income, education and insight, and behavioural changes appear to be dominant influences. One example is the large improvement in the health of children under age five in these regions (which cannot only be ascribed to medicine and health engineering).

Thus, major improvements in health have been achieved over recent decades in terms of both decreases in overall morbidity and mortality and more specific parameters such as the incidence of infectious diseases or perinatal and infant mortality (WHO, 1993; World Bank, 1993b). Life expectancy has increased nearly everywhere, and this has led to increases in population, despite declining birth rates in many countries (UN, 1994). In some countries, however, this fertility transition is slow or stagnating.

At the moment, children under age five account for more than 25 per cent of global mortalities. ( See Figure 4.20.) These occur almost exclusively in developing countries, where 85 per cent of mortality (10.6 million deaths) in children under age 5 is caused by communicable diseases nearly half of them diarrhoeal diseases. (See Figure 4.21.) Nevertheless, mortality in children under age 5 attributable to communicable diseases in developing countries is declining; if this trend continues, it will lead to significant decreases in global mortality.

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