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Water Supply And Pollution Control 8th Edition Pdf 20

Environmental pollution has many facets, and the resultant health risks include diseases in almost all organ systems. Thus, a chapter on air and water pollution control links with chapters on, for instance, diarrheal diseases (chapter 19), respiratory diseases in children and adults (chapters 25 and 35), cancers (chapter 29), neurological disorders (chapter 32), and cardiovascular disease (chapter 33), as well as with a number of chapters dealing with health care issues.

Water Supply And Pollution Control 8th Edition Pdf 20

Each pollutant has its own health risk profile, which makes summarizing all relevant information into a short chapter difficult. Nevertheless, public health practitioners and decision makers in developing countries need to be aware of the potential health risks caused by air and water pollution and to know where to find the more detailed information required to handle a specific situation. This chapter will not repeat the discussion about indoor air pollution caused by biomass burning (chapter 42) and water pollution caused by poor sanitation at the household level (chapter 41), but it will focus on the problems caused by air and water pollution at the community, country, and global levels.

Estimates indicate that the proportion of the global burden of disease associated with environmental pollution hazards ranges from 23 percent (WHO-1997) to 30 percent (Smith, Corvalan, and Kjellstrom 1999). These estimates include infectious diseases related to drinking water, sanitation, and food hygiene; respiratory diseases related to severe indoor air pollution from biomass burning; and vectorborne diseases with a major environmental component, such as malaria. These three types of diseases each contribute approximately 6 percent to the updated estimate of the global burden of disease (WHO 2002).

As the World Health Organization (WHO) points out, outdoor air pollution contributes as much as 0.6 to 1.4 percent of the burden of disease in developing regions, and other pollution, such as lead in water, air, and soil, may contribute 0.9 percent (WHO 2002). These numbers may look small, but the contribution from most risk factors other than the "top 10" is within the 0.5 to 1.0 percent range (WHO 2002).

Because of space limitations, this chapter can give only selected examples of air and water pollution health concerns. Other information sources on environmental health include Yassi and others (2001) and the Web sites of or major reference works by WHO, the United Nations Environment Programme (UNEP), Division of Technology, Industry, and Economics ( ); the International Labour Organization (ILO), the United Nations Industrial Development Organization (UNIDO; ), and other relevant agencies.

Table 43.1 indicates some of the industrial sectors that can pose significant environmental and occupational health risks to populations in developing countries. Clearly, disease control measures for people working in or living around a smelter may be quite different from those for people living near a tannery or a brewery. For detailed information about industry-specific pollution control methods, see the Web sites of industry sector organizations, relevant international trade union organizations, and the organizations listed above.

Chemical pollution of surface water can create health risks, because such waterways are often used directly as drinking water sources or connected with shallow wells used for drinking water. In addition, waterways have important roles for washing and cleaning, for fishing and fish farming, and for recreation.

Chemicals can enter waterways from a point source or a nonpoint source. Point-source pollution is due to discharges from a single source, such as an industrial site. Nonpoint-source pollution involves many small sources that combine to cause significant pollution. For instance, the movement of rain or irrigation water over land picks up pollutants such as fertilizers, herbicides, and insecticides and carries them into rivers, lakes, reservoirs, coastal waters, or groundwater. Another nonpoint source is storm-water that collects on roads and eventually reaches rivers or lakes. Table 43.1 shows examples of point-source industrial chemical pollution.

The variety of hazardous pollutants that can occur in air or water also leads to many different interventions. Interventions pertaining to environmental hazards are often more sustainable if they address the driving forces behind the pollution at the community level rather than attempt to deal with specific exposures at the individual level. In addition, effective methods to prevent exposure to chemical hazards in the air or water may not exist at the individual level, and the only feasible individual-level intervention may be treating cases of illness.

Interventions to reduce pressures on environmental quality include those that limit hazardous waste disposal by recycling hazardous substances at their site of use or replacing them with less hazardous materials. Interventions at the level of the state of the environment would include air quality monitoring linked to local actions to reduce pollution during especially polluted periods (for example, banning vehicle use when pollution levels reach predetermined thresholds). Interventions at the exposure level include using household water filters to reduce arsenic in drinking water as done in Bangladesh. Finally, interventions at the effect level would include actions by health services to protect or restore the health of people already showing signs of an adverse effect.

Water pollution control requires action at all levels of the hierarchical framework shown in figure 43.1. The ideal method to abate diffuse chemical pollution of waterways is to minimize or avoid the use of chemicals for industrial, agricultural, and domestic purposes. Adapting practices such as organic farming and integrated pest management could help protect waterways (Scheierling 1995). Chemical contamination of waterways from industrial emissions could be reduced by cleaner production processes (UNEP 2002). Box 43.4 describes one project aimed at effectively reducing pollution.

The cost-effective interventions in the air pollution area could be of value in developing countries as their industrial and transportation pollution situations become similar to the United States in the 1960s. The review by Tengs and others (1995) does not report the extent to which the various interventions were implemented in existing pollution control or public health programs, and many of the most cost-effective interventions are probably already in wide use. The review did create a good deal of controversy in the United States, because professionals and nongovernmental organizations active in the environmental field accused the authors of overestimating the costs and underestimating the benefits of controls over chemicals (see, for example, U.S. Congress 1999).

A number of publications review and discuss the evidence on the costs and benefits of different pollution control interventions in industrial countries (see, for example, U.S. Environmental Protection Agency 1999). For developing countries, specific data on this topic are found primarily in the so-called gray literature: government reports, consultant reports, or reports by the international banks.

One of the early examples of cost-benefit analysis for chemical pollution control is the Japan Environment Agency's (1991) study of three Japanese classical pollution diseases: Yokkaichi asthma, Minamata disease, and Itai-Itai disease (table 43.3). This analysis was intended to highlight the economic aspects of pollution control and to encourage governments in developing countries to consider both the costs and the benefits of industrial development. The calculations take into account the 20 or 30 years that have elapsed since the disease outbreaks occurred and annualize the costs and benefits over a 30-year period. The pollution damage costs are the actual payments for victims' compensation and the cost of environmental remediation. The compensation costs are based on court cases or government decisions and can be seen as a valid representation of the economic value of the health damage in each case. As table 43.3 shows, controlling the relevant pollutants would have cost far less than paying for damage caused by the pollution.

A few studies have analyzed cost-benefit aspects of air pollution control in specific cities. Those analyses are based mainly on modeling health impacts from exposure and relationships between doses and responses. Voorhees and others (2001) find that most studies that analyzed the situation in specific urban areas used health impact assessment to estimate impacts avoided by interventions. Investigators have used different methods for valuing the economic benefits of health improvements, including market valuation, stated preference methods, and revealed preference methods. The choice of assumptions and inputs substantially affected the resulting cost and benefit valuations.

Pandey and Nathwani (2003) applied cost-benefit analysis to a pollution control program in Canada. Their study proposed using the life quality index as a tool for quantifying the level of public expenditure beyond which the use of resources is not justified. The study estimated total pollution control costs at US$2.5 billion per year against a monetary benefit of US$7.5 billion per year, using 1996 as the base year for all cost and benefit estimates. The benefit estimated in terms of avoided mortality was about 1,800 deaths per year.

Aunan and others (1998) assessed the costs and benefits of implementing an energy saving and air pollution control program in Hungary. They based their monetary evaluation of benefits on local monitoring and population data and took exposure-response functions and valuation estimates from Canadian, U.S., and European studies. The authors valued the average total benefits of the interventions at US$1.56 billion per year (with 1994 as the base year), with high and low bounds at US$7.6, billion and US$0.4 billion, respectively. They estimated the cost-benefit ratio at 1 to 3.4, given a total cost of interventions of US$0.46 billion per year. Many of the benefits resulted from reduced mortality in the elderly population and from reduced asthma morbidity costs. 350c69d7ab


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