Frumkin, 2e Part Two: Environmental Health on a Global Scale. Chapter 11: Developing Nations

Transcription

1 Frumkin, 2e Part Two: Environmental Health on a Global Scale Chapter 11: Developing Nations

2 One Earth, Three Worlds The First World (also referred to as developed countries, Upper Earth, or developed economies), the Second World (high-income developing countries, Middle Earth, or developing economies) and Third World (low-income developing countries, Lower Earth, or underdeveloped economies). There are health gaps that exist between the nations of the different worlds. People in most countries of the Third World are disproportionately exposed to the so-called traditional hazards (generally associated with lack of development), which differ from the modern hazards (Second World) of uncontrolled industrial development and the postmodern hazards (First World) of sedentary lifestyles and material excess. Risk transitions and risk overlap occur as developing nations move from one stage into the next.

3 The Changing Disease Burden in the Third World The probability of death is remarkably different in the three worlds, with the death rates in Third World countries being much higher and occurring at younger ages. The world s population will age considerably in the future, being propelled by decreased fertility rates and decreased mortality rates. The effect of the environment on this demographic transition, in terms of the health of the elderly population, is that this population needs more attention than it is currently getting.

4 The Changing Disease Burden in the Third World Some approaches to measuring the health of populations, other than mortality rates, have been identified. One such approach is the disability-adjusted life years (DALYs) concept, which combines years of life lost (YLL) through premature death with years lived with disability (YLD). One DALY can be thought of as one lost year of healthy life, and the measured disease burden is the gap between the health status of a given population and that of a normative global reference population with high life expectancy lived in full health. Estimated DALYs for children and young adults for 2002 show a disproportionate burden of disease in Third World countries compared to the developed countries.

5 Drivers of Environmental Health Factors that motivate, stimulate, or push the environmental processes that affect human health are referred to as environmental drivers. These factors include population growth, technological and economic development, changing lifestyles and social attitudes, natural processes of change in the physical environment, policy interventions, and the long-term impacts of past human interventions. These drivers contribute both directly and indirectly to health disparities among the three worlds. Some environmental drivers include vulnerability and coping capacity, globalization, agriculture and food security, and urbanization.

6 Vulnerability and Coping Capacity The vulnerability of any human population to external stresses is a function of exposure, sensitivity, and adaptive capacity. Two main elements of human vulnerability are exposure to environmental hazards (stressors, shocks, and contingencies) and coping capacity, which can offer security in the face of exposure. Human environmental vulnerability occurs along a continuum ranging from highly vulnerable (undesirable) to highly secure (desirable). Having high risk, insecure populations leads to the creation of environmental refugees from the Third World. These are the large numbers of the world s least secure people, who are forced to seek refuge from insecure and hazardous biophysical environments.

7 Globalization The process of interlocking economic, social, technological, political, and cultural changes emerging around the world is called globalization. An unmistakable outcome of the globalization phenomenon so far is that as the economies grow, people in the First World get richer, some in the Second World escape poverty, and disparities with the Third World widen. Indeed, despite the extraordinary advances of the twentieth century, huge disparities persist in the morbidity and mortality experienced in the First and Third Worlds, and this is due primarily to the ill effects of poverty.

8 Agriculture Due to social, political, and economic constraints and lack of education, undernutrition remains a leading risk factor for ill health and premature death in most Third World countries. Subsistence agriculture does not provide adequately for Third World populations, and there is need for the integration of more modern techniques of food production, which would allow the feeding the local population and the growth cash crops for the export market.

9 Food Security Environmental factors, including water availability, the physical and chemical properties of soils, and prevailing climatic conditions, control local food patterns. These factors also determine the bioavailable forms of essential microelements in soils and hence their concentrations in foods. Foods in many developing countries thus tend to be naturally deficient in some essential microelements.

10 The Impact of Undernutrition Hunger and undernutrition remain the most pervasive risk factors for human morbidity and mortality, especially in the developing countries. Factors that can influence the availability and equitable distribution of safe, nutritious, and affordable foods in developing countries include traditional beliefs that limit food choice, reduced capacity for local food production, declining investments in agriculture, the destruction of local ecosystems, and lack of adequate food-storage and distribution systems. Undernutrition leads to increased vulnerability to disease, and is particularly a threat to the very young and very old.

11 Overnutrition On the other end of the nutrition spectrum in developing countries lies the problem of overnutrition. Diets are shifting toward a higher fat content, more refined carbohydrates, less fiber, more salt, and more diversity. This Westernization process also involves changes in living and working patterns as people shift to less physical activity and less labor and also to smoking cigarettes. This changing pattern in dietary habits and physical inactivity has given rise to overnutrition, with attendant hypertension, hyperlipidemias, overweight, and obesity, which are in turn risk factors for chronic diseases such as cancers, heart disease, stroke, diabetes, and mental illness.

12 Urbanization and Urbanicity Today, for the first time in human history, the number of people living in towns and cities exceeds the number living in rural areas. There is a distinction between urbanicity the extent of urban population concentration and urbanization the process over time of urban growth. In wealthy countries, there is typically a high degree of urbanicity, including the presence of megacities, but with slowly expanding or stable populations. In contrast, rapid urbanization is more common among cities in developing world. The rate of urbanization may be a more important predictor of health in urban populations than the population size. This is because with rapid urbanization, population growth may outstrip available resources.

13 Urbanization and Urbanicity The rapid growth of urban areas is the result of two factors: natural increase in population (excess of births over deaths) and migration to urban areas. When First World countries enter economically into Third World countries, they often implement structural adjustment plans, which displace local farmers in favor of balkanized production. These displaced farmers, in turn, are forced into urban areas to look for work.

14 The Growth of Slums The high rate of urban growth with consequent increase in demand for basic housing and services, as well as skewed distribution of investment toward affluent suburban developments, has resulted in rapid expansion of illegal or unplanned and unserviced settlements with unhealthy living conditions and extreme overcrowding.

15 Urban Health in Developing Nations In developing countries, urban residents, especially those in unplanned or unserviced settlements (squatter camps and slums), often lack access to adequate housing and basic amenities including sanitation, piped water, waste disposal, and electricity. Additionally, the physical environment includes many stressors such as chemical and biological agents, natural disasters, noise pollution, and extreme heat.

16 Urban Health in Developing Nations Ambient Air Pollution: High levels of ambient air pollution generated by industrial and transportation related sources, as well as combustion byproducts from domestic cooking and heating. Indoor Air Pollution: In megaslums that have formed in the outskirts of Third World cities, access to electricity is unreliable, and people depend on dirty-burning fuels for cooking, causing pollution within their homes. Water: Water demand may outstrip the supply. What s more the chemical and biological agents prevalent in urban areas may contaminate water supplies. Infectious Diseases: Infectious diseases flourish in the low-income urban settlement common in developing countries. High population density, crowded conditions, and concentration of commerce facilitate the emergence and reemergence of infectious diseases by increasing the probability of transmission.

17 Urban Health in Developing Nations Waste Disposal: Illegal dumping and burning of solid wastes and sewage in the informal settlements, and the tendency for polluting industries, waste dumps, and waste management facilities to be located near low-income neighborhoods can contribute to pollution and exposure. Additionally, bad sanitation may lead to contaminated water supplies and human wastes finding their way into the local food chain. Disaster Vulnerability: Many cities in developing nations are located to the coast and are vulnerable to sea-level rise, extreme weather events, and flooding. Additionally, the poor quality of construction in many urban areas leads to increased damage during a natural disaster. Social and Behavioral Factors: Increasing urbanization has resulted in lower quality diets, increased participation in sexual activity, insufficient access to adequate healthcare, and few legal rights.

18 Health Disparities across the Three Worlds There are three main areas that present problems to the First, Second, and Third Worlds: air quality, water and sanitation, and injuries.

19 Air Pollution The global perspective reveals a clear dichotomy in air pollution trends. In First World countries levels of many pollutants have declined markedly, the combined result of technical, legislative, and community interventions. In most developing countries, in contrast, levels of air pollution continue to rise, reflecting growing fossil fuel consumption and intensification of manufacturing activities. Ambient air pollution has been linked to a variety of chronic and acute health effects.

20 Indoor Air Pollution Many people in Third World countries rely on burning biomass fuels for energy. These fuels typically are burned indoors in simple household devices, such as a pi and in small rooms without adequate ventilation. These highly inefficient burners cause incomplete combustion, resulting in high volumes of harmful air pollutants. Exposure to indoor air pollution from biofuel combustion has been linked, with varying degrees of robustness, to a number of health outcomes, including acute respiratory infection (ARI), middle ear infection (otitis media), chronic obstructive pulmonary disease (COPD), lung cancer (mainly from coal smoke), asthma, etc. The common cooking technique of smoking and drying food by hanging it over burning biomass can cause the food to be coated in harmful pollutants.

21 Lead Poisoning There are a variety of sources by which individuals can be exposed to lead, including automobile parts, lead house paints, and iron and steel production. Concerns of lead in gasoline have largely been answered by the switch to unleaded gas; however, exposure to lead is still prevalent due to the large scale smelting operations that occur in many nations.

22 Sanitation and Water Quality Approximately 900 million people in developing countries live without continuous access to safe drinking water. In low-income developing countries, close to 50% of the population has access to safe drinking water, as compared to 75 to 9 0% in high-income developing countries and more than 90 percent in developed countries. Rural populations in low-income developing countries have considerably less access to safe drinking water than do those living in urban areas.

23 Sanitation, con t Sanitation plays a large role in the maintenance of a clean water supply; however, only 62% of the world s population has access to improved sanitation facilities. When water quality is not cared for, microbial contamination of source water, lack of sanitation services, and inadequate personal hygiene form a triad that gives rise to communicable diseases. Some efforts have been made to increase safe drinking water in the Third World, to use Safe Water Systems, to reduce contaminants.

24 Injuries Injuries can be divided into two broad categories: intentional injuries (such as rape, battery, child and spousal abuse, suicide, police or military brutality, and war-related violence) and unintentional injuries (such as road traffic injuries, harm from fires, drownings, falls, poisonings, injuries resulting from natural disasters, and workplace injuries. Together, injuries from these sources constitute a hidden epidemic among young adults in the developing countries. In particular, road traffic injuries are problematic.

25 Injuries con t Most injuries are associated directly or indirectly with environmental risk factors and are thus preventable. Examples of environmental factors that drive injuries include poorly designed cookstoves; poorly designed roadways; substandard housing at risk of collapse; inadequate land use planning that places people in the path of flooding and landslides; accidental poisonings by pesticides; and festering domestic and interpersonal violence. A clear transition in injury risks occurs with a change in level of development. Injuries from fires, agricultural injuries, drownings, wood-acquisition injuries, and war-related violence dominate the early stages of development, whereas road traffic, intentional, and industrial injuries appear to increase with economic development.