HOW FAST ARE SUPPLIES BEING USED UP? The future supply of mineral resources depends on two factors: (1) the actual or potential supply and (2) the rate at which that supply is being used. Most published supply estimates refer to reserves: known deposits from which a usable minerals can be extracted profitably at current price. Depletion time is the time it takes to use a certain portion (usually 80%) of the reserves of a mineral at a given rate of use. Minerals essential to our economy are called critical minerals, those necessary for national defense are called strategic minerals. The definition of “critical” or “strategic” may vary from country to country or from time to time. WHO HAS THE WORLD’S NONFUEL MINERAL RESOURCES? Nonfuel minerals resources are unevenly distributed in the world. The Russia, the United States, Canada, Australia, and South Africa supply most of the world’s 20 most important nonefuel minerals. Japanon the otehr hand, has virtually no metals, in addition to lacking coal, oil and timber resources. No industrialized country is self-sufficient in mineral resources. Even though it is the world’s largest producer of nonfuel minerals, the United States must import 50% or more of 24 of its 42 most important nonfuel minerals. Experts are concerned about four strategic minerals: manganese, cobalt, platinum, and chromium-for which the U.S. has little or no reserves and depends on imports from the Russia, South Africa, Zambia and Zaire. “Without manganese, chromium, platinum, and cobalt, there can be no automobiles, no airplanes, no jets engines, no satellites, and no sophisticated weapons-not even home appliances. We stockpile critical and strategic minerals to cushion against short-term supply interruptions and price jumps. These supplies are “supposed” to last through a three-year conventional war. ENVIRONMENTAL IMPACTS The greatest danger from resource consumption is the damage that their extraction and processing do to the environment. Mining and mineral processing are among the most environmentally damaging of all human activities. The minerals industry accounts for 5-10% of world energy use, making it a major contributor to air and water pollution and to greenhouse gases. In the U.S. nonfuel mining produces at least six times more solid waste than all municipal garbage. Today’s low mineral prices do not include the full costs of forests denuded, land gouged or eroded, rivers dammed and land flooded to supply electricity for metal processing, displaced and poisoned indigenous peoples, air pollution, water pollution and vegetation destroyed. FINDING NEW LAND-BASED MINERAL DEPOSITS Geologic exploration guided by better knowledge, satellite surveys, and other new techniques will increase present reserves of most minerals. New mineral discoveries will be mostly in unexplored areas of LDC’s. Antarctica may contain large mineral deposits. However, mining this harsh land may be too expensive. Moreover, environmentalists believe we should protect this last remaining large wilderness area from development. MINING THE OCEANS Ocean mineral resources are found in three areas: seawater, sediments and deposits on the shallow continental shelf, and sediments and nodules on the deep-ocean floor. Most of the chemical elements found in seawater occur in such low concentrations that recovering them takes more energy and money than they are worth. Only magnesium, bromine, and sodium chloride are abundant enough to be extracted profitably at present prices with current technology. Continental shelf deposits and placer deposits are already significant sources of sand, gravel, phosphates, and nine other nonfuel mineral resources. Offshore wells also supply large amounts of oil and natural gas. The deep-ocean floor may be a future source of manganese and other metals. For example, at a few sites manganese-rich nodules have been found in large quantities. These cherry-to potato-sized rocks contain 30-40% by weight manganese, used in certain steel alloys. They also contain small amounts of other strategically important metals, such as nickel, copper, and cobalt. These nodules might be sucked up or scooped up from the ocean floor to a mining ship. However, most of these nodule beds occur in international waters and there are squabbles over who owns them. WASTING RESOURCES: SOLID WASTE AND THE THROWAWAY APPROACH SOURCES OF SOLID WASTE With only 4.7% of the world’s population, the United States produces 33% of the solid waste: any unwanted or discarded material that is not a liquid or a gas. The United States, the world’s most material nation, generates about 11 billion tons of solid waste per year (about44 tons per person). While garbage produced directly by households and business is a significant problem, about 98.5% of the solid waste in the U.S. comes from mining, oil and natural gas production, agriculture, and industrial activities. Although mining waste is the single largest category of U.S. solid waste, the EPA has done little to regulate its disposal, mostly because Congress has specifically exempted mining wastes from regulation as a hazardous waste. Most industrial solid waste, such as scrap metal, plastics, paper, ash removed by air pollution control equipment and sludge from waste treatment plants, is buried or incinerated at the plant site where it was produced. The remaining 1.5% of solid waste produced in the United States is municipal solid waste from homes and businesses. The biggest component in the U.S. landfills is paper and paperboard (38% by volume), followed by plastic (18%), metals (14%), yard waste (11%), food (4%), glass (2%), and other materials (13%). About 17% of these potentially usable resources is recycled or composted. The other 83% is hauled away and dumped (66%) or burned (17%) at a cost of about $30 billion per year (projected to rise to $75 billion by 2000). Litter, such as helium filled balloons, is also a source of solid waste. DEALING WITH SOLID WASTE There are two ways to deal with the mountains of solid waste we produce: waste management and pollution (waste) prevention. Waste management is a throwaway or highwaste approach that encourages waste production and then attempts to manage the wastes in ways that will reduce environmental harm-mostly by burying them or burning them. However, even the best-designed waste incinerators release some toxic substances into the atmosphere and leave a toxic residue that must be disposed of-usually in landfill. Even the best-designed landfills leak wastes into groundwater. And eventually we run out of affordable or politically acceptable sites for landfills and incinerators. The basic problem is that modern economic systems give higher rewards to those who produce waste instead of those who try to use resources more efficiently. We give timber, mining, and energy companies tax write-offs and other subsidize to cut trees and to find and mine copper, oil, coal, and uranium. We seldom subsidize companies and businesses that recycle copper or paper, use oil or coal more efficiently, or develop renewable alternatives to fossil fuels. That tilts the economic playing field against waste prevention. The main goal of the low-waste approach is not to reduce the volume of solid waste and make landfills last longer. Instead, it is to reduce the depletion of resources and decrease the pollution and environmental degradation caused by resource extraction, processing, and use. This prevention approach has hierarchy of goals: Reduce waste and pollution by preventing its creation Reuse as many things as possible Recycle and compost as much waste as possible Incinerate or treat waste that can’t be reduced, reused, recycled, or composted Bury what is left in state-of-the-art landfills after the first four goals have been met. REDUCING WASTE AND POLLUTION By reducing unnecessary waste of nonrenewable mineral resources, plastics, and paper, pollution and waste prevention can extend supplies even more dramatically than recycling and reuse. Cutting waste generally saves more energy and virgin resources than recycling, and reduces the environmental impacts of extracting, processing, and using resources. One of the best ways to reduce municipal solid waste and pollution is to cut down on unnecessary packaging, which makes up about 50% by volume and 30% by weight of municipal waste. Packaging accounts for 50% of all paper produced in the United States, 90% of all glass, 11% of all aluminum, and 3% of all energy used. REUSABLE CONTAINERS Recycling, though and important step, still reinforces the throwaway mentality. A much more important step is reuse in which a product is used again in its original form. One example is the refillable glass beverage bottle. In 1964, 87% of beer and soda containers in the United States were refillable glass bottles, but since then most local bottling companies have been bought up or driven out of business by aluminum and large soft-drink companies. Refillable glass bottles now make up only 11% of the market. Refillable glass bottles can be used 50 times or more. Collected and filled at local bottling plants, they reduce transportation and energy costs, and create local jobs. To encourage use of refillable glass bottles, Ecuador has a beverage container deposit fee that is 50% higher than the cost of the drink. This has been so successful that bottles as old as 10 years continue to circulate. Most plastic bottles can’t be refilled because the FDA requires that refillable containers be sterilized, and most plastic can’t take the heat. Furthermore, some plastics, unlike glass and aluminum, tend to absorb minute quantities of what they contain. However, since 1989 Coca-Cola and PepsiCo have been selling reusable PET plastic bottles in Europe and South America, where local bottling plants still exist in large numbers. The bottles can be refilled 20-30 times. Another reusable container is the metal or plastic lunch box that most workers and schoolchildren once used. Today many people carry their lunches in throwaway paper or plastic bags. At work people can have their own reusable glasses, cups, dishes, utensils, cloth napkins, and towels, and can use handkerchiefs instead of tissues. Some schools have persuaded school boards to switch from Styrofoam lunch trays to washable dishes. THE DIAPER DILEMMA The 18 billion disposable diapers used each year in the U.S. take up 2-4% by volume of municipal solid waste and take 200-500 years to degrade in landfills. New biodegradable diapers take 100 years degrade in a landfill. Production of disposable diapers uses trees, consumes plastic (about 1/3 of each diaper is plastic), and creates air and water pollution. Cloth diapers can be washed and reused 80-200 times, and then used as rags, which keeps the roughly 10,000 disposable diapers the average baby uses from reaching landfills. Cloth diapers save trees and money. For example, the disposable diapers needed for one baby cost about $1,533. A cloth diaper service costs about $975, and washing cloth diapers at home costs about $283. But consider this, washing cloth diapers produces 9 times more air pollution and 10 times more water pollution as disposable diapers. Cloth diapers also consume 6 times more water and 3 times more energy than disposables. So the choice between disposable diapers and reusable cloth diapers is not clear-cut. Many people opt for cheaper cloth diapers and use disposable ones for trips or at child-care centers. TIRES There are now 2-3 billion used tires heaped in landfills, old mines, abandoned houses, and other dump sites throughout the United States. About 7% are recycled or reused, 9% are incinerated to produce energy, and 5% are exported. The remaining 79% are landfilled, stockpiled, or dumped illegally. Tire dumps are fire hazards and breeding grounds for mosquitoes. In 1989 there were at least 87 tire fires in the U. S. that burned for weeks or months, polluting the air with soot, carbon dioxide, and particles of toxic metals such as lead and zinc. Water sprayed onto the burning tires can carry the oil and other toxic substances with it, and pollute nearby surface water and groundwater. Used tires can be put to a number of uses. In California, a power plant burns tires to generate enough electricity for 15,000 homes. The plant sits next to the world’s largest pile of tires. Other companies convert used tires into heating oil and high-octane compounds that can substitute for lead in gasoline. Other companies use pulverized tires to make resins for products ranging from car bumpers and garbage cans to road-building materials. If asphalt pavement were required to contain at least 20% rubber, this could create a market for 100 million tires per year in the U.S. SOLUTIONS: COMPOSTING AND RECYCLING COMPOSTING Biodegradable solid waste from the slaughterhouses and food-processing plants, kitchen and yard waste, manure from animal feedlots, wood, and municipal sewage sludge can be mixed with soil and decomposed by aerobic bacteria to produce compost, a sweet-smelling, dark-brown humus that is rich in organic matter and soil nutrients. It can be used as an organic soil fertilizer or conditioner, as topsoil, or as a landfill cover for golf courses, parks, forests, roadway medians, and the grounds around public buildings. CLOSING THE LOOP There are two types of recycling: primary and secondary. The most desirable type is primary, or closed-loop, recycling, in which products are recycled to produce new products of the same type--newspaper into newspaper and aluminum cans into aluminum cans, for example. The less desirable type is secondary, or open-loop, recycling, in which waste materials are converted into different products. OBSTACLES TO RECYCLING Several factors hinder recycling (and reuse) in the United States. One is that Americans have been conditioned by advertising and upbringing to accept a throwaway lifestyle. Another is that many of the environmental and health costs of items are not reflected in their market prices, so consumers have little incentive to recycle, reuse, or reduce their use of throwaway products. Another serious problem is that the logging, mining, and energy industries get huge tax breaks, depletion allowances, cheap access to public lands, and other subsidies to encourage them to extract virgin resources as quickly as possible. By contrast, recycling industries get few tax breaks or other subsidies. Finally, the lack of large, steady markets for recycled materials makes recycling a risky boom-and-bust business that attracts little investment capital. OVERCOMING THE OBSTACLES Studies suggest that with a vigorous program by 2000 the United States could reuse, recycle, and compost 60-80% by weight of the municipal solid waste resources it now throws away by instituting the following measures: - Pass a national beverage container deposit law. - Require that all soda and beer bottle have a few standardized size, forms, and colors so that any bottler can refill any returned bottles. - Add a tax on virgin materials. - Give tax break on products that are easy to repair, reuse, or recycle (primary only) and tax products that are not. - Cut federal and state subsidies for primary-materials industries. - Use advertising and education to discourage the throwaway mentality. - Require consumers to sort household wastes for recycling, or give them financial incentives for recycling. - Encourage municipal and backyard composting by banning the disposal of yard wastes in landfills. Recycling municipal solid waste is important, but it only puts a small dent in the overall solid-waste problems. For example, if everyone in the United States recycle all of their personal solid waste, 98.5% of the nation’s solid waste would still remain. BURNING SOLID WASTE In trash-to-energy incinerators trash is burned as a fuel to produce steam or electricity, which can be sold or used to run the incinerator. Most are mass-burn incinerators, which burn mixed trash without separating out hazardous materials (such as batteries) and noncombustible materials that can interfere with combustion conditions and pollute the air. Denamark and Sweden burn 50% of their solid waste to praduce energy, compared with 17% in the United States. Incinerating solid waste kills germs and reduces the volume of waste goin to landfills by about 60%. However, incinerators are costly to build, operate, and maintain, and they create very few long-term jobs. Moreover, even with advanced air pollution control devices, incinerators put highly toxic dioxins and furans, and tiny particles of lead, cadmium, mercury, and other toxic substances that can cause cancer and nervous system disorders, into the atmosphere. And without continuous maintenance and good operator training and supervision, the air pollution control equipment on incineration often fails, so that emission standads are exceeded. Environmentalists have pushed congress and the EPA to classify incinerator ash as hazardous wasten as is done in Japan. To date, however, no action has been taken, largely because waste management companies claim it would make inceneration too expensive. Environmentalists counter thatif the companies can’t properly dispose of the toxic ash they produce, they shouldn’t be in the incineration business. GARBAGE GRAVEYARDS About 69% by weight of the municipal solid waste in the United States is buried in sanitary landfills. A sanitary landfill is a garbage graveyard in which wastes are spread out in thin layers, compacted, and covered daily iwht a fresh layer of clay or plastic foam. The world’s largest landfill is in Fresh Kills on Staten Island. It is as big as 16,000 baseball diamonds and is the final resting place for 80% of New York City’s trash. It is as tall as a 15-story building, and when it reaches its capacity, probably around 2005, it will be as tall as a 50-story building. Fresh Kills opened in the early 1970s, before the EPA required stricter standards for new sanitary landfills. As a result, it has no liner, and each day 3.8 million liters (1 million gallons) of contaminated leachate oozes into groundwater beneath Fresh Kills. Fortunately, Staten Island residents do not rely on groundwater to meet their water needs. Modern state-of-the-art landfills are lined with clay and plastic before being filled with garbage. This liner collects leachate (rainwater that is contaminated as it percolates down through the solid waste) and is supposed to keep it from leaking into groundwater. Collected leachate (“garbage juice”) is pumped from the bottom of the landfill, stored in tanks, and sent either to a regular sewage treatment plant or to an 0n-site treatment plant. When the landfill is full, it is covered with clay, sand, gravel, and topsoil to prevent water from seeping in. Several wells are drilled around the landfill to monitor any leakage of leachate into nearby groundwater. Methane gas produced by anaerobic decomposition in the sealed landfill is collected and burned to produce steam or electricity. Sanitary landfills offer certain benefits. No airpolluting open burning is allowed. Odor is seldom a problem, and rodents and insects cannot thrive. After a landfill has been filled, the land can be graded, planted, and used as a park, a golf course, a ski hill, an athletic field, a wildlife area, or some other recreation area. However, landfills also have drawbacks, paper and other biodegradable wastes break down very slowly in today’s compacted and water-and oxygen-deficient landfills. For example, newspapers dug up from some landfills are still readable after 30-40 years, and hot dogs, carrots, and chickens that have been dug up after 10 years have not rotted. The underground anaerobic decomposition of organic wastes at landfills produces toxic hydrogen sulfide gas, explosive methane gas, and smog-forming volatile organic compounds that escape into the air. Landfills can be quipped with vent pipes to collect these gases and the collected methane burned to produce steam or electricity. Contamination of groundwater and nearby suface water is another serious problem, especially for thousands of older unlined and abandoned landfills. When rain filters through a landfill it leaches out inks, water-soluble metal compounds, and other toxic materials. This produces a contaminated leachate that seeps from the bottom of unlined landfills. Only 11% of U.S. landfills collect leachate, and only 25 % monitor groundwater. Even when leachate is collected it is rarely treated to render it harmless. Moreover, 86% of the landfills studied have contaminated groundwater. Once groundwater is contaminated it is extreamly difficult - often impossible - to clean up. And while modern double-lined landfills delay the release of toxic leachate into groundwater below landfills, they do not prevent it. HAZARDS AND RISK A hazard is any substance or action that can cause injury, disease, economic loss, or environmental damage--in short, a danger. Risk is the possibility of suffering harm from a hazard. It is expressed in terms of probability--a mathematical statement about how likely it is that something will happen. Risk assessment involves using data, assumptions, and models to estimate the probability of harm to human health or to the environment that may result from exposures to specific hazards. COMMON HAZARDS Here are some hazards that people face: - Cultural hazards. These include unsafe living and working conditions smoking, poor diet, drugs, drinking, driving, criminal assault, unsafe sex, and poverty. - Chemical hazards. These result from harmful chemicals in air, water, food, and soil. - Physical hazards. These include ionizing radiation, noise, fires, floods, drought, tornadoes, hurricanes, landslides, earthquakes, and volcanic eruptions. - Biological hazards. These are disease-causing bacteria and viruses, pollen, parasites, and animals such as pit bulls and rattlesnakes.
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