WHO: Drinking Water, Sanitation & Disease

Drinking Water, Sanitation, and Disease

• Approximately 1.7 billion cases of diarrheal disease occur each year, resulting in about 760,000 deaths of children under the age of five
• The major cause of diarrhea is infections of the digestive tract caused by the ingestion of disease organisms in food or water
• Providing safe drinking water and access to toilets or latrines can prevent diarrhea, but 20% of the world's population lives on $1.25 per day or less, making it impossible for individuals to provide their own safe drinking water supplies and sanitary facilities

Risk and Cost

• Most decisions involve considering two factors: risk and cost
• Risk is the probability that a condition or action will lead to an injury, damage, or loss
• Probability is a mathematical statement about how likely it is that something will happen
• Consequences of a bad outcome resulting from accepting a risk may be minor or catastrophic
• Economic cost of dealing with bad outcomes is one of the consequences of accepting a risk

Characterizing Risk

• Risk assessment uses facts and assumptions to estimate probability of harm to people or the environment from particular environmental factors or conditions
• Several sources of information and tools are used to help clarify the risk
• If a situation is well known, scientists use statistics based on past experience to estimate risks

Risk Management

• Risk management is a decision-making process that involves using the results of risk assessment and selecting actions to minimize or eliminate the risk
• It is included as part of all good environmental management systems within business and industry
• The deciding question in risk management is: What degree of risk is acceptable?

Perception of Risk

• One of the most profound dilemmas facing decision makers and public health scientists is how to address the discrepancy between the scientific and public perceptions of environmental risks
• Numerous studies have shown that environmental hazards truly affecting health status in the country are not necessarily those receiving the highest attention

Environmental Economics

• Economics is the study of how people choose to use resources to produce goods and services and how these goods and services are distributed to the public
• Environmental problems are primarily economic problems
• Resources can be categorized into three kinds: land (natural resources), labor (human resources), and capital (technology and knowledge)

Resources

• Natural resources can be renewable or nonrenewable
• Renewable resources are formed or regenerated by natural processes, such as soil, vegetation, animals, air, and water
• Nonrenewable resources are not replaced by natural processes, or the rate of replacement is so slow as to be ineffective, such as iron ore, fossil fuels, and mountainous landscapes

Supply and Demand

• Supply is the amount of a good or service people are willing to sell at a given price
• Demand is the amount of a good or service that consumers are willing and able to buy at a given price
• The relationship between supply and demand is often illustrated with a supply/demand curve

Environmental Costs

• Pollution, species extinction, resource depletion, and loss of scenic quality are all examples of the environmental costs of resource exploitation
• Environmental costs are difficult to measure, since they are not easily converted to monetary values

The Economics of Pollution

• Pollution is any addition of matter or energy that degrades the environment for humans and other organisms
• Pollution-prevention costs are those incurred either in the private sector or by government to prevent, either entirely or partially, the pollution that would otherwise result from some production or consumption activity
• The philosophy of pollution prevention is that pollution should be prevented or reduced at the source whenever feasible

Cost-Benefit Analysis

• Cost-benefit analysis is a formal process for calculating the costs and benefits of a project or course of action, to decide if benefits are greater than costs
• In the United States, the National Environmental Policy Act of 1969 mandates environmental impact statements for major government-supported projects

Comparing Economic and Ecological Systems

• Many environmental problems are symptoms of an imbalance between the socioeconomic system and the natural world
• Economic systems have short time scales (years to minutes), whereas ecological systems have longer time scales (years to centuries)
• Economic systems can occur anywhere, whereas ecological systems occur in specific places
• Economic systems measure in money, whereas ecological systems measure in physical and biological units (grams of biomass, population size, etc.)

Life Cycle Analysis and Extended Product Responsibility

• Life-cycle analysis is the process of assessing environmental effects associated with production, reuse, and disposal of a product over its entire useful life
• Extended product responsibility is the concept that the producer of a product is responsible for all negative effects involved in its production, including the ultimate disposal of the product

Sustainability Characteristics

• Renewability: the ability to maintain or restore natural resources and ecosystems over time
• Substitution: the use of alternative resources or materials to reduce the environmental impact of a product or process
• Interdependence: the interconnectedness of social, economic, and environmental systems
• Adaptability: the ability to adjust to changing circumstances and adapt to new information
• Institutional commitment: the commitment of organizations and governments to sustainable development

Economics and Sustainable Development

• Sustainable development is development that meets present needs without compromising the ability of future generations to meet their own needs
• Most definitions refer to the viability of natural resources and ecosystems over time, and to maintenance of human living standards and economic growth