U N FOUR ENVIRONMENTAL HEALTH AND SAFETY 485
CHAPTER 15 ENVIRONMENTAL CONCERNS: WASTES AND POLLUTION CHAPTER QUTLINE CHAPTER OBJECTIVES SCENARIO After studying this chapter you will be able to: INTRODUCTION 1 Define the terms environment, ecology, and \biospbere. NATURAL ENVIRONMENTAL HAZARDS Explain how human activities affect the envi- RESIDUES AND WASTES FROM HUMAN ronment through the production of wastes ACTIVITIES and residues. TYPES OF WASTES AND POLLUTION 3Name the primary sources of solid waste. Solid Waste. Hazardous Waste Air Pollution )List and briefly explain the four approaches to Water and Its Pollution. Radiation. Noise solid waste management Pollution 5 Define bazardous waste CHAPTER SUMMARY 6 Explain the difference between sanitary and SCENARIO: ANALYSIS AND RESPONSE secured landfills. Identify six ways to deal with hazardous ACTIVITIES stes waste COMMUNITY HEALTH ONTHE WEB 8)Explain what is meant by the term Superfund. REFERENCES (9)Explain the Pollutant Standard Index (PSD) Briefly describe acid rain, ozone layer, global \warming, and photochemical smog. 11Identify the major indoor air pollutants 12 Explain the difference in point source and nonpoint source pollution. 13Identify the three categories of water pollu- tion 4) Briefly describe waste water treatment. 15 List means of conserving water. 6 Name the primary sources of radiation. 7 Explain how nuclear wastes are handled in 18 Identify the two basic characteristics of sound 19 Identify steps to deal with noise pollution. 486
CHAPTER 15 ENVIRONMENTAL CONCERNS: WASTES AND POLUTION. 487 centre d Mary recently accepted jobs as teachers chemicals. The sanitarian recommended that Tom the Blackford school Corporation. When they and Mary drink bottled water until the well water moved to the Blackford community, they pur could be tested further. After some investigation, chased a modest home on five acres of land out county officials determined that Mary and Toms side the city. They had only been living in their 15-year-old home had been built close to a former new home two months when they noticed that landfill that had been closed about 20 years ear their water was beginning to taste different The lier. Tom and Mary were now faced with an ource of their water was a well on their own expensive, unforeseen, and long-term problem, not property. A testing of the water by the local health to mention the devaluation of their property. department sanitarian revealed that their water was contaminated with lead and perhaps other INTRODUCTION health are affected by the quality of our environment, and the way we live our lives& As human beings, we are a part of the environment in which we live. Our lives and all the external influences the quality of the environment. In this chapter we explain in detail and I inin r illustrate with examples the ways in which our interactions with the environment surrounding and have direct consequences for the quality of our lives. While this chapter seeks to and develogment of describe and define wastes and pollution, Chapter 16 examines more specifically an organism or The environment is defined as all the external conditions, circumstances and/ ogontramro the health consequences of these environmental hazards influences surrounding and affecting the growth and development of an organism or a community of organisms. In order to fully understand environmental concerns that threaten our health, we must understand how we interact with our environ- ecology ment. The study of how living things interact with each other and their environ- between organisms ment is called ecology, and the zone of the earth where life is found is known as and their evironment the biosphere. NATURAL ENVIRONMENTAL HAZARDS biosphere the zone of the earth where life is found While the purpose of this chapter is to point out and explain environmental hazards associated with human activities, it is important to recognize the ex tence and influence of natural hazards in the environment that damage or destroy wildlife habitats, kill or harm humans, and damage property. These hazards naiural hazards may be physical, biological, chemical, or even psychological or social. Physical that incease hazards are caused by forces either internal to the earth's surface or on the sur- proboliltyof disease face itself. Natural hazards resulting from internal forces include earthquakes and iniury or death volcanos. Those on the surface include winds lightning, storms, floods, fires, and of humans drough
488. UNIT FOUR ENVIRONMENTAL HEALTH AND SAFETY Biological hazards for humans are, for the most part, limited to microbiological gents such as pathogenic bacteria, parasites and viruses, and their toxic biological products. Examples include malaria, plague, tuberculosis, and human immunodef ciency virus(HIv). Examples of biological toxins include the toxin produced by the tetanus bacteria, poisons produced by certain mushrooms, and the poisoning of marine life by"red tides Biological hazards and their resulting epidemics were the topic of Chapter 4 and will not be discussed here. Chemical hazards are noni ological substances that are toxic enough to threaten human health Two other categories of hazards are psychological and sociological hazards Psychological hazards affect a person s outlook on life Psychological hazards are just as real and damaging to health as physical hazards. Boredom, stress, fear, and depression represent psychological hazards that consume significant health care dollars. A workplace can be most unproductive if the workers are highly stressed bored, or depressed. The fear of losing a job and other economic factors can also weigh heavily on members of a community. Entire communities may have prob- lems if their young people are bored or frustrated The final classification of environmental hazards is that of sociological haz. ards. Sociological hazards occur when societies interact in destructive ways or fail to interact in productive ways. Overcrowding and war are sociological hazards Some would say Adolph Hitler, the German dictator before and during World War Il, was a sociological hazard; others might nominate the late drug kingpin Pablo Escobar. RESIDUES AND WASTES FROM HUMAN ACTIVITIES More than any other species on our planet, humans have the power to significantly alter the environment through individual and community activities. These activities include working, traveling, leisure-time activities, and simply living at home Likewise, environmental conditions such as weather, climate, and topography affect human activities. As people participate in their daily activities, they continually pro- residues and duce residues and wastes On any typical day a person in the United States might unwanted by produts generate the following types of residues and wastes: Human body wastes: urine and feces(waste water) 2. Excess materials and foods: trash and garbage 3. Yard wastes: grass clippings and tree branches 4. Construction and manufacturing wastes: scrap wood and metal, contaminated water solvents, and excess heat and noise 5. Agricultural wastes: animal dung, run-off from feedlot operations, crop residues, animal carcasses. 6. Transportation wastes: carbon monoxide, gaseous pollutants, and used motor 7. Energy production wastes: mining wastes, electrical power(combustion of coal)wastes, nuclear power(radioactive)wastes, and weapons production (radioactive) wastes
CHAPTER 15 ENVIRONMENTAL CONCERNS: WASTES AND POLUTON 489 FIGURE 15.1 A healthy environment supports a healthy community A healthy environment, one relatively free from pollution, supports healthy communities(see Figure 15. 1). Residues and wastes from human activities can adversely affect the environment by damaging wildlife habitats, undermining food production, contaminating sources of water, altering climate, and threatening human health Factors contributing to an ever-increasing number of environmental hazards are: (1)urbanization, (2)industrialization, 3) human population growth, and(4) the production and use of disposable products and containers. Urbanization, the urbanization process in which people come together to live in cities, often results in people the proces by which living in overcrowded conditions and inadequate space for the disposal of wastes, to live in ife making waste management more difficult(see Figure 15.2). Concomitant industri. alization, resulting in the generation of new types of wastes, has complicated the waste disposal problem because of the generation of hazardous waste Population growth has also contributed to the overall waste disposal problem, as has the reliance on disposable containers. Not only are there more people than there were 30 years ago, but the amount of refuse generated by each person as we enter the twenty-first century is much greater than it was in the 1960s, when reusable containers began to be replaced by throwaway containers(see Table 15.1)
490. UNIT FOUR ENVIRONMENTAL HEALTH AND SAFETY CAKDRIDCE·50 MERVILLE FIGURE 15.2 Urbanization has led to overcrowding and pollution While it is unrealistic to believe humans can have a pollution-free environ- ment,it is possible to work toward minimizing the level of pollution. As the domi- nant species on this planet, our very survival depends upon our recognition of the deleterious effects our activities have on the rest of the biosphere and our taking responsibility for minimizing these effects. If the environment is to remain rela tively stable, the frequency and severity of environmental hazards stemming from human activities must be reduced Table 15.1 Reusable versus Throwaway Consumer Goods Reusable goods Throwaway Goods Milk bottles Cardboard cartons and plastic jugs Returnable soft drink bottles Aluminum cans and plastic bottles Garbage cans Trash bags Lunch boxes Paper bags Cloth napkins Paper napkins Refillable pens Disposable pens Handkerchiefs Facial tissues Cloth towels or rags Paper towels Ceramic or plastic dishes Paper plates
CHAPTER 15 ENVIRONMENTAL CONCERNS: WASTES AND POLUTON 491 TYPES OF WASTES AND POLLUTION The types of wastes and pollution discussed below include solid wastes, hazardous wastes,air pollution, water pollution, radiation, and noise pollution. While some types of wastes may merely lower the aesthetic value of the environment, others constitute either an immediate or longterm threat to human health and well being Solid Waste Household trash, grass clippings, tree trimmings, manure, excess stone generated from mining, and steel scraps from automobile plants are all examples of solid waste.Today we are generating solid wastes in record quantities. In the last 40 olid fom years, the daily solid waste production per person in the United States jumped agriculture, and from just over 2.5 pounds to almost 4.5 pounds. Many communities have used up businesses all available space to bury their solid waste. If they cannot find a neighboring com- munity to accept their waste they must ship it elsewhere(see Figure 15.3) Sources of Solid waste Most solid waste can be traced to five major sources: agriculture, mining, industry, municipalities(domestic sources) and utilities. By far, agriculture generates the greatest volume of solid waste, more than 50% of the total (see Figure 15.4). Examples of agricultural wastes include crop residues, manures, and other vegeta tion trimmings. Most solid waste generated by farming will decompose, enriching FIGURE 15.3 Solid waste is becoming such a problem in some areas that it is shipped elsewhere
492. UNIT FOUR ENVIRONMENTAL HEALTH AND SAFETY the soil, or can be fed to animals or otherwise used as energy Farms have long been known for recycling their own nonhuman solid waste Unlike agricultural waste, mining waste does not decompose in any reasonable period of time nor can it be reused in any other manner. As the extraction of the earth's natural resources intensifies, mining wastes will constitute even greater problems. Mining waste makes 12% up about 39% of the total amount of solid waste gener 3.1% ated by humans The solid waste resulting from industrial production 64% is quite varied and constitutes 6.4% of the total Examples include paper, wood chips, and highly com lex chemicals. Certain industrial waste products are especially hazardous because of their toxicity, corrosive ness, or flammability. Agriculture Municipal Household or municipal waste makes up just over Industrial 3% of all solid waste generated each year. It includes wastes generated by individual households, busi nesses FIGURE 15. 4 and institutions located within municipalities. This Sources of solid waste waste is known as municipal waste. While it makes up Source: McKinney, M. L, and R. M. Schoch(1998) nly 3. 1% of unicipal solid waste Environmental Science: Systems and Solutions. Web receives considerable attention because it is visible mal- enhanced edition. Sudbury, MA: Jones and Bartlett dorous, and considered a threat to human health if not sposed of properly The heterogeneous makeup of municipal solid waste precludes efficient dis- osal. There are seven major categories: paper, yard waste, rubber, textiles and wood,metal, glass, plastic, and food wastes(see Figure 15.5). Forty years ago food businesss. und wastes were the primary component in municipal solid waste, but garbage dis- unicipolitis posals in homes and the preprocessing of foods have reduced that greatly. Today, institutions located PGpm①3% the total. mud由书pk吗me the burning of coal. Solid Waste Management lid waste Strictly defined, solid waste management is the collection, transportation, and disposal of solid waste. a broader definition of solid waste management also includes source-reduction efforts that limit the production of solid waste in the disposal of solid waste first place. Though the preponderance of solid waste is created by agriculture and mining, the following discussion of solid waste management is aimed primarily at municipal and industrial wastes, which create greater problems in the environ mental system Collection The handling of municipal solid waste can be divided into two steps: collection and disposal. Approximately 80% of the money spent on waste management is spent on the collection process. Faced with ever-increasing amounts of waste
CHAPTER 15 ENVIRONMENTAL CONCERNS: WASTES AND POUUTION. 493 37.5% 179% 24% 28% 63% 6.7% 63%67% FIGURE 15.5 Paper and paperboard Ferrous metals Types and percentages of municipal Yard wastes Plastics and leather McKinney, M. L, and r.M. Glass Food wastes Miscellaneous edition. Sudbury, MA: Jones greater efficiency is needed in collecting the wastes so that more money can be pent on environmentally sound disposal. Traditionally, municipal wastes have been collected at the curb or alley by crews of three people and a large truck However, experience has shown that crew size, truck size, and special-feature trucks-like those that can be operated by a single person or those with different storage compartments for separating the trash-can improve efficiency and reduce sanitary landfills waste disposal site cost(see Figure 15.6). Moreover, the collecting and transporting of trash through on land suited for this pipelines hydraulically and/or pneumatically(the method used at Disney World) purpose and upon can make collection even more efficient which waste is spread Currently most municipalities dispose of their wastes in sanitary landfills, sites layer of day or plasic judged suitable for inground disposal of solid waste. However, many of these foam each day municipal landfills are filling up, and the availability of land suitable for new landfill sites near cities is quickly disappearing. Disposal of municipal solid waste on unsuitable land can result in the contamination of groundwater (water found in the ground), which may be the community's only source of drinking water. To meet integrated waste the need for better management of solid waste, many communities have adopted app an integrated waste management approach. This approach combines the fol- lowing four methods in a way best suited to local needs and capabilities: (1) sani. dispin ofsold tary landfills, (2)incineration, (3)recycling, and (4)source reduction. 2 sanitary lo incineratiOn Sanitary landfill Prior to the mid-1970s much of the solid waste in the United States was simply source reduction placed in a hole in the ground with little thought given to the underlying soil type
49·UN盯 FOUR ENVIRONMENTAL HEALTH AND SAFETY FIGURE 15.6 Household waste picked up at the curbside with a segregated container, recycling truck location, and depth of groundwater and little concern for neighbors. These open dumps, while cheap and convenient, were unsanitary because they supported open pits in whic large populations of rodents, flies, and vermin. Such dumps also produced leachates, liquids created when water mixes with wastes and removes soluble constituents from them by percolation, which too often found their way into underlying groundwater Dumps were a health hazard and reduced the value of adjacent property because of their obnoxious odors, their unsightliness, and their generally unsanitary conditions. ater mixes w The passage of the Resource Conservation and Recovery Act of 1976 soluble constituents(RCRA, pronounced Rick-Rah) provided legislation that phased out open dumps from them by and required that the disposal of solid waste be done in sanitary landfills. Unlike dumps, sanitary landfills are supposed to be located at sites that can geographically and geologically support them, sites with natural clay soils. If clay soil cannot be found, a clay lining must be constructed to prevent leachates from reaching groundwater. Sanitary landfills are not to be located over sand or gravel deposits ation nd Recovery Act of that would allow leachates to reach ground water. Second, in sanitary landfills all refuse is spread and compacted in thin layers by bulldozers. Once the compacted the federal low that sets forth guidelines layers are about eight to ten feet thick, they are covered with about six inches of soil, compacted again, and readied for another ayer of refuse. At the end of each andling nd disposa day, unlike an open dump, refuse is covered with a layer of soil. This process con of hazardous wos tinues until the landfill is full, at which time a final layer of soil about two feet thick is placed on the top. When this process is strictly followed, sanitary landfills pro-
