with other fibers and spun or milled into cloth. The shorter, or “nonspinning,” fibers are generally made into compressed, molded, or cast products, such as as- bestos pipe and sheet, in which thefibersare added to a binder such as portland cement or plastic. Such products account for most of the asbestos produced each year. Of the six different minerals that have been produced as asbestos, only crocidolite and amosite have been produced in important quantities. Produc- tion of anthophyllite, tremolite, and actinolite has been extremely limited and was nonexistent by the end of the twentieth century. Uses of Asbestos Although the individual properties of asbestos miner- als differ from one another, they share to varying de- grees several properties that make them useful and cost-effective. These include nonflammability, great resistance to heat and acid attack, high tensile strength and flexibility, low electrical conductivity, resistance to friction, and a fibrous habit. Over a span of only a few years, the public’s view of asbestos changed dramatically: Once considered a useful commodity, asbestos became known as an ex- tremely dangerous material. The change began with passage of the Clean Air Act (1972), which classified asbestos as a carcinogenic material because studies of workers exposed to high concentrations of asbestos dust for many years showed a high incidence of asbes- tosis, a lung disease that decreases the ability to breathe, and mesothelioma, a cancer of the lungs. Then, in 1973, a lawsuit against a number of asbestos manufacturers on behalf of an asbestos worker was decided against the companies. Litigation mounted, and, in 1982, manufacturer Johns-Manville filed for bankruptcy in the face of overwhelming litigation; eventually, as a compromise measure, the company established a $2.5 billion fund to pay future asbestos claims. Widespread publicity concerning asbestos hazards led to a near hysteria among the general public; many people were afraid to send their children to a school unless asbestos insulation had been removed. People brought lawsuits demanding that asbestos be re- moved from public buildings. The courts awarded large damage rewards based on the argument that low-level exposure to asbestos should be considered dangerous because a safe level of exposure had not been scientifically established. This led to the “single fiber” concept—that exposure to only one fiber of as- bestos may be deadly—in keeping with a widely held public perception that there should be no exposure to carcinogenic materials in the environment. The “asbestos scare” was largely the result of mass media sensationalism and resultant political and legal pres- sure rather than the result of scientific investigation. For example, very few people realized that, according to scientific estimates, apersonbreathing normal out- door air inhales nearly 4,000 asbestos fibers per day, or more than 100 million over a lifetime. Asbestos can be a health hazard, but the serious- ness depends on the length of exposure, the amount of asbestosinthe air,and thetype of asbestosinvolved. The danger to miners and others working with asbes- tos in unprotected conditions is demonstrable, but the danger to the general public from minimal expo- sure has been greatly exaggerated. Some researchers believe that the danger is so small as to be virtually nonexistent. Melvin Benarde in Asbestos: The Hazard- ous Fiber (1990) outlined the statistical risks (the num- ber of deaths expected per 100,000 people) for a number of potential hazards. The risk of dying from nonoccupational exposure to asbestos is one-third the risk of being killed by lightning and nearly five thousand times less than the chance of dying in a car 70 • Asbestos Global Resources U.S. End Uses of Asbestos, 1977 vs. 2003 Metric Tons End Use 1977 2003 Cement pipe 145,000 — Cement sheet 139,500 — Coatings & compounds 32,500 1,170 Flooring products 140,000 — Friction products 83,100 — Insulation: electrical 3,360 — Insulation: thermal 15,000 — Packing & gaskets 25,100 — Paper products 22,100 — Plastics 7,260 — Roofing products 57,500 2,800 Textiles 8,800 — Other 30,200 677 Source: Data from the U.S. Geological Survey. Note: U.S. mining of asbestos ended in 2002. accident. Nevertheless, by the mid-1990’s more than $35 billion had been spent on asbestos abatement in rental, commercial, and public buildings. Most com- mon uses of asbestos—applications such as pipeline insulation, clothing, and roofing felt—were banned in the United States in 1990, and virtually all asbestos products were banned in the country by 1996. It has been estimated that in the time period from 1965 to 2029 there will be 432,465 asbestos-related cancers in the United States. Although this figure has been disputed by some epidemiologists and other ex- perts, it is enough to indicate the misery that many will suffer because of their exposure to asbestos. Nev- ertheless, the litigation-centered approach to asbes- tos issues in the United States has been criticized. In a 2003 report, the Manhattan Institute’s Center for Le- gal Policy described asbestos litigation as the longest- running mass tort in the history of the nation and arguably the most unjust. Some critics have claimed that the massive asbestos tort litigation is more likely to enrich lawyers than relieve victims. The Manhattan Institute estimated that of the $70 billion paid out by companies for asbestos claims, $40 billion has gone to plaintiffs and defense lawyers. Numerous companies have beendriven intobankruptcyby asbestos lawsuits, some ofwhich had onlya tangential connectionto the original asbestos exposure. Of the twenty-nine com- panies thatfiled forbankruptcyin the yearsfrom 2000 to 2002 because of asbestos litigation, six were valued at more than $1 billion. These included such indus- trial giants as Owens Corning, W. R. Grace, and U.S. Gypsum. As the companies that directly produced as- bestos have gone under, plaintiffs’ lawyers have in- creasingly sued companies outside the asbestos and building products industry. Companies in more than one-half of all industries in the United States have been sued over asbestos. With the total eventual cost of asbestos litigation estimated at $200 billion, Con- gress has considered several proposals to establish a compensation fund in place of litigation. In 2004, in- dustrial states such as Michigan and Ohio enacted measures to implement some form of asbestos tort re- form. Although asbestos use has become rare in devel- oped countries, the same cannot be said of develop- ing economies. In most of Europe and North Amer- ica, use of asbestos is strictly limited or banned by law. However, emerging nations have continued and even increased the use of asbestos in manufacturing and building. Countries such as China, India, Brazil, Iran, Global Resources Asbestos • 71 Data from the U.S. Geological Survey, . U.S. Government Printing Office, 2009.Source: Mineral Commodity Summaries, 2009 220,000 175,000 380,000 300,000 925,000 100,000 Metric Tons 1,050,000900,000750,000600,000450,000300,000150,000 Zimbabwe China Canada Brazil Kazakhstan Russia Other countries 75,000 World Mine Production of Asbestos, 2008 and South Korea are major consumers of asbestos. As - bestos mining is widespread in Africa. Many develop- ing nations consider the low costand the effectiveness of asbestos as an industrial material to outweigh the health risks. The adverse effects of asbestos as an in- dustrial pollutant are below the surface and long- term. Many of these nations face a more obvious health risk from such epidemics as HIV/AIDS, chol- era, tuberculosis, and malaria, which have been linked to poverty or inadequate infrastructure. Like- wise, many developing nations have accepted a great deal of air, water, and ground pollution as the price of accelerating the growth of fragile economies. Asbes- tos has apparently been accepted as another pollut- ant. Certainly these countries lack the extensive and ubiquitous legal and regulatory system of the United States that has focused attention on asbestos. How- ever, in some African nations, such as South Africa and Swaziland, compensation for workers suffering the effects of asbestos has been provided. China is perhaps the most dynamic and fastest- growing of all emerging markets. Many have specu- lated that China will emerge as the most important economy ofthe twenty-first century.It is worth noting, therefore, some facts about asbestos consumption in China. China continues to make extensive use of as- bestos. Production of asbestos in China has remained steady since 1995. China is one of the five leading pro- ducers ofasbestos but isperhapsits leadingconsumer. Imports of asbestos to China rose from 1,083 metric tons in 1990 to 145,425 metric tons in 2003, an in- crease nearly 150-fold. Estimates indicate that more than 100,000 workers in Chinaare exposed to asbestos. Although the Chinese government has official poli- cies against pollutants, they are often not enforced. With the United States and China taking such dif- ferent approaches to the use of asbestos, it is not yet possible to speak of a unified world approach to this industrial product. Certainly its use, associated health risks, and remediation represent one of the most im- portant confluences of industry, medical concerns, and law in the world economy. Gene D. Robinson, updated by Howard Bromberg Further Reading Carroll, Stephen, et al. Asbestos Litigation. Santa Monica, Calif.: Rand Corporation, 2005. Castleman, Barry. Asbestos: Medical and Legal Aspects. 5th ed. New York: Aspen, 2005. Chatterjee, Kaulir Kisor. “Asbestos.” In Uses of Indus - trial Minerals, Rocks, and Freshwater. New York: Nova Science, 2009. Craighead, John E., and Allen R. Gibbs, ed. Asbestos and Its Diseases. New York: Oxford University Press, 2008. Deffeyes, Kenneth S. “Asbestos.” In Nanoscale: Visual- izing an Invisible World. Illustrations by Stephen E. Deffeyes. Cambridge: Massachusetts Institute of Technology Press, 2009. Dodson, Ronald, and Samuel Hammar, eds. Asbestos: Assessment, Epidemiology, and Health Effects. Boca Raton, Fla.: CRC Press, 2005. Guthrie, George D., Jr., and Brooke T. Mossman, eds. Health Effects of Mineral Dusts. Washington, D.C.: Mineralogical Society of America, 1993. Harben, Peter W., and RobertL. Bates. Industrial Min- erals: Geology and World Deposits. London: Industrial Minerals Division, Metal Bulletin, 1990. Kogel, Jessica Elzea, et al., eds. “Asbestos.” In Indus- trial Minerals and Rocks: Commodities, Markets, and Uses. 7th ed. Littleton, Colo.: Society for Mining, Metallurgy, and Exploration, 2006. McCulloch, Jock, and Geoffrey Tweedale. Defending the Indefensible: The Global Asbestos Industry and Its Fight for Survival. New York: Oxford University Press, 2008. McDonald, J. C., et al. “The Health of Chrysotile As- bestos Mine and Mill Workers of Quebec.” Archives of Environmental Health 28 (1974). Maines, Rachel. Asbestos and Fire: Technological Trade- offs and the Body at Risk. New Brunswick, N.J.: Rutgers University Press, 2005. Skinner, H. Catherine W., Malcolm Ross, and Clifford Frondel. Asbestos and Other Fibrous Materials: Miner- alogy, Crystal Chemistry, and Health Effects. New York: Oxford University Press, 1988. Web Sites Manhattan Institute Center for Legal Policy Trial Lawyers Inc.: Asbestos http://www.triallawyersinc.com/asbestos/asb01.html U.S. Geological Survey Asbestos: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/asbestos U.S. Geological Survey Mineral Commodities Profiles—Asbestos http://pubs.usgs.gov/circ/2005/1255/kk 72 • Asbestos Global Resources See also: Clean Air Act; Health, resource exploita - tion and; Hydrothermal solutions and mineraliza- tion; Metamorphic processes, rocks, and mineral de- posits; Silicates. Asphalt Category: Products from resources Where Found Before the growth of the petroleum industry in the early twentieth century, when asphalt began to be mass-produced, naturally occurring asphalt was found in pools of petroleum-heavy deposits, most no- tably Trinidad’s 46-hectare Pitch Lake (off the coast of Venezuela), the 4,000-hectare Bermudez Lake in Venezuela, and areas around the Dead Sea basin in Is- rael and Jordan. Primary Uses Asphalt is most associated with road-surface paving. Apart from highway constructionand repairs, asphalt is used for airport runways, running tracks, and drive- ways. In addition, asphalt is a waterproofing agent in fabrics, irrigation systems, roofing shingles, jetties and sea walls designed to combat beach erosion, and insulation. More than 60 billion metric tons of manu- factured asphalt are used annually in the United States alone. Technical Definition Asphalt is a by-product of petroleum refining, either occurring naturally over geologic eras or processed industrially in the controlled refining process called fractional distillation that occurs once naphtha, gaso- line, and kerosene have all been extracted from the crude. It is difficult to define a single chemical profile because asphalt varies depending on the grade of crude petroleum and the type of refining production used. Generally, asphalts contain saturated and unsat- urated aliphatic compounds (organic compounds whose carbon atoms configure in open branches rather than closed rings) and aromatic compounds (organic compounds whose carbon atoms configure in closed rings) with up to 150 carbon atoms. Asphalt contains about 80 percent carbon, 10 percent hydro - gen, and 6 percent sulfur with trace amounts of oxy - gen and nitrogen. Molecular weight varies. These compounds are further classified by their solubility— more insoluble compounds are called asphaltenes and less soluble compounds maltenes. Description, Distribution, and Forms Asphalt is a dark (brown or black), cementitious (highly adhesive) material. Its predominant elements are bitumens, solid and/or semisolid high-molecular- weight hydrocarbons. Because more than 80 percent of commercially produced asphalt is used for paving, the properties of asphalt are graded according to its performance as a pavement adhesive, particularly how well it holds up over time, specifically in the areas of aging, stiffening, and cracking. Only 5 percent of the asphalt used today is natu- rally occurring. Its most prominent naturally occur- ring site is Pitch Lake in the petroleum-rich southwest corner of the island of Trinidad, near the town of La Brea. Although difficult to determine dimensions with any accuracy because it grows and shrinks, this “lake”—it is more accurately a sludgy 40-plus-hectare mineral deposit created by a slow underground seep- age of asphalt, or pitch—is estimated to be more than 35 meters across and 107 meters deep at its deepest point (the edges of the lake are crusty and support weight, but toward the center of the lake, the pitch becomes characteristically stickyand far more hazard- ous, easily swallowing entire objects). Given its dimen- sions, the lake has provided an apparently inexhaust- ible supply of asphalt for centuries—large holes left by removing asphalt are quickly filled in as the lake maintains a kind of fluid dynamic. Western explorers were fascinatedby the phenomenaof this vasttar lake, not merely for the usefulness of the asphalt (they im- mediately used it to upgrade the waterproofing on their ships)but because thelake also preservedthe re- mains of prehistoric mammals and birds. Commercially produced asphalt is primarily a taffylike binder known as asphaltic concrete. Asphal- tic concrete, atacky, ductile resin suspended in an oily medium, maintains the integrity of aggregate parti- cles. Because asphaltic concrete is highly sticky, it must be heated into liquid to be used for pavement construction. It is most often sprayed on a graded roadbed. Itis then compactedinto the properdensity, usually 25 to 30 centimeters. Because it solidifies into a tough and flexible surface able to maintain its integ- rity against both the weight and frequency of traffic and the deformations from weather conditions (nota - bly ice and extreme heat), asphalt remains the pri - Global Resources Asphalt • 73 mary roadway surface. Given the diminishing supply of fossil fuel and concerns over the depletion of that resource, asphaltic concrete is attractive because more than 80 percent of removed asphalt can be recycled for new road projects. History Asphalt was used as early at 3600 b.c.e. by the Sumer- ians as a mortar adhesive for paving and building and as a waterproofing agent in canal construction and public pools (records indicate it also was used for medical treatments, statuary enhancement, and mummification throughout the Middle East). Pitch is mentioned early in the Bible: It binds Noah’s ark and later makes waterproof the bulrush basket in which the baby Moses is set adrift on the Nile. Following the discovery of huge natural depositsof pitch in South America in the fifteenth and sixteenth centuries (notably by Sir Walter Ralegh), asphalt be- came a commercially viable waterproofing agent for the burgeoning shipbuilding industry. Not until 1870, however, was asphalt first tested for paving. The idea came from accounts discovered among Incan archives dating back to the twelfth century. A stretch of streets in Newark, New Jersey, was made of Trinidad asphalt. Its appeal was evident—it was cheap to import, easy to apply, flexible,and once hardened madefor a smooth ride. Within six years, asphalt was selected for a most ambitious—and prestigious—paving project: Penn- sylvania Avenue in Washington, D.C. By the turn of the century, more than 35 million square meters of streets inAmerica were asphalt.Withthe rise ofthe oil industry, however, commercially produced asphalt became more profitable. Obtaining Asphalt Asphalt may be obtained directly from sludgy beds near petroleum fields. However, far more asphalt is obtained as a small fraction of residue distilled during the refining process of crude oil. Heavy crude oil is heated to nearly 370° Celsius in large furnaces. As the crude is processed, lighter components vaporize and are released into the atmosphere through refinery towers (in the early 1980’s, facing pressure from envi- ronmental groups, the petroleum industry over- hauled the distillation towers to minimize pollution). To render the remaining asphalt into asphaltic ce - ment, the residue is distilled further through a vac - 74 • Asphalt Global Resources Russian workers repave an asphalt road on the outskirts of Abakan. (Kolbasov Alexander/ITAR-TASS/Landov) uum process designed to prevent the residue from cracking, and thenit is mixed with theappropriate ag- gregate materials, mostcommonly crushed rock, slag, sand, and/or cement stone. In turn, the asphalt must be stored (and transported) at a constant 65.55° Cel- sius to ensure liquidity. If the asphalt must be trans- ported a considerable way, kerosene or diesel oil can be temporarily added and then separated before the asphalt is applied to the roadbed. Uses of Asphalt Long before the automobile made highway construc- tion a pressing concern, as thousands of kilometers of roadway needed to be laid quickly and economically, asphalt was valued because it was waterproof. It revo- lutionized the shipping industry because of its caulk- ing ability. Even in modern society, asphalt helps so- lidify sea walls to protect against the effects of tides, waves, and harsh weather. In addition, asphalt lines the retaining tanks in industrial fish hatcheries, pre- serves the integrity of irrigation systems (before as- phalt, up to one-third of water transported would be lost in transit), and maintains holdings by providing underlining for reservoirs. Furthermore, asphalt has become a primary liner for the disposal of hazardous waste and a liner at landfill sites. In addition, because it is waterproof and fire retar- dant, asphalt can be used, when combined with felt and mineral granules, to produce the familiar rectan- gular roofing shingles. This asphalt is slightly harder than paving asphalt (it is typically heated at a much higher temperature to make it less flexible). Asphalt shingles are remarkably adaptable to a variety of roof- ing needs and styles; shingles can be adjusted for the slope of the roof, climate conditions, and even house design. However, asphalt is best known as a paving agent. It is durable, tough, and flexible enough to provide a comfortable riding surface. Industry standards mea- sure durability of standard asphalt roadways at fifteen to twenty years. That longevity is most often compro- mised by cracks from water seeping into the surface during the winter, freezing, and then cracking the up- per layers or by ruts that appear during hot summers when the asphalt softens. However, asphalt provides for relatively easy repairs. The durability of asphalt, particularly its capacity to hold up under constant traffic and enormous weights, has made it the pri - mary coating for airplane runways. For much the same reason, asphalt is also used for railroad beds and even subway system track beds. Finally, asphalt is used for smaller, high-volume traffic surfaces such as walk- ing trails, tennis courts, biking paths, running tracks, basketball courts, golf-cart paths, and playgrounds. Users of these recreational surfaces appreciate the give in asphalt, as compared to concrete surfaces. In 1986, the National Center for Asphalt Technology (NCAT) was established at Auburn University to de- velop asphalt production quality. Joseph Dewey Further Reading Karnes, Thomas L.Asphalt Politics: AHistory of theAmer- ican Highway System. Jefferson, N.C.: McFarland, 2009. Lavin, Patrick. Asphalt Pavements: A Practical Guide to Design, Production, and Maintenance for Engineers and Architects. London: Spon Press, 2003. Nicholls, Cliff. Asphalt Surfacing: A Guide to Asphalt Surfacingsand Treatments Used for the Surface Course of Road Pavements. London: Spon Press, 1998. O’Flaherty, C. A. Highways: The Location, Design, Con- struction,and Maintenance of Road Pavements. 4th ed. Oxford: Butterworth-Heinemann, 2002. Web Site National Center for Asphalt Technology http://www.eng.auburn.edu/center/ncat See also: Petroleum refining and processing; Renew- able and nonrenewable resources; Transportation, energy use in. Aspinall, Wayne Category: People Born: April 3, 1896; Middleburg, Ohio Died: October 9, 1983; Palisade, Colorado Aspinall, a Colorado Democrat, served in the U.S. Congress from 1948 to 1972. From 1958 to 1972, he chaired the House Interior and Insular Affairs Com- mittee, shaping some of the most important natural re- source legislation in American history. Biographical Background Wayne Norviel Aspinall’s shadow loomslargeover the modern American West. After growing up near Pali - Global Resources Aspinall, Wayne • 75 sade, Colorado, on the Grand (now Colorado) River, Aspinall attended Denver University, served in World War I, becamea schoolteacher, obtaineda law degree, and ran a peach orchard business. Always active in lo- cal Democratic Party politics, he served as a state rep- resentative andsenator for sixteen yearsbefore he was elected to Congress in 1948. Aspinall quickly made a name for himself as an ex- pert on public land and federal reclamation issues. In 1958, he began chairing the House Interior and Insu- lar Affairs Committee, a posthe did not relinquish un- til after his defeat in the 1972 Colorado primary. Dur- ing Aspinall’s twenty-four-year congressional career, his name became synonymous with some of the most notable legislation that shaped the landscape of the American West, including the Upper Colorado River Storage Act (1956), the Wilderness Act (1964), and the Colorado River Basin Act (1968). From 1964 until 1970, he chaired the Public Land Law Review Com- mission, which made dozens of recommendations for reforming the management of the nation’s federal lands. Impact on Resource Use By the mid-1960’s, Aspinall’s strict adherence to a multiple-use philosophy of resource management had made him a target for environmentalist criticism. In 1970, political columnist Jack Anderson labeled Aspinall the environmentalists’ “most durable foe” and accused him of defending timber, oil, cattle, and chemical interests “against the beauty of American nature.” To Aspinall, nature had been placed in the stewardship of humankind, and while he appreciated the American West’s beauty, he always favored the controlled use of its resources over what he saw as the program of “extreme” environmentalists who, in his view, wanted to “lock up” the region’s resources. Steven C. Schulte See also: Bureau of Reclamation, U.S.; Dams; Energy politics; Irrigation; Public lands; Wilderness Act. Astor, John Jacob Category: People Born: July 17, 1763; Waldorf, near Heidelberg, Germany Died: March 29, 1848; New York, New York Astor, a leader in early American capitalism, founded the American Fur Company, considered the first Amer- ican business monopoly. Astor’s astounding financial success, although atypical, pointed to the fortunes that could be made from the exploitation of resources in the young and resource-rich United States. Biographical Background As a young man aboard a ship from Germany, John Ja- cob Astor learned about the lucrative fur trade in North America. In 1786, three years after arriving in New York City, he opened a fur-goods store and began dealing directly with American Indians to secure his furs. In 1796, as his area of activity expanded, Astor se- cured a charter from the British East India Company. This charter opened foreign markets, especially the rich fur market of China. 76 • Astor, John Jacob Global Resources John Jacob Astor earned most of his multimillion-dollar fortune in the fur trade. (Library of Congress) Impact on Resource Use Astor establishedthe AmericanFur Company in1808. In 1811, in an attempt to gain control of fur trade in the Northwest, he founded thetown of Astoria in Ore- gon. However, this plan failed when the British cap- tured Astoria during the War of 1812. The setback was temporary, and by 1827, Astor had obtained his mo- nopoly of the American fur trade. Astor’s trading empire benefited from his friend- ship with U.S. presidents such as Thomas Jefferson, who appointed Astor executive agent in the North- west. An Astor ship was also allowed to go to China during the Embargo Act of 1807, producing a profit of $200,000. Exploitation of human and natural re- sources was the inevitable result of Astor’s activities. American Indians, to whom the profit motive was hitherto unknown, were exploited because of their skill in obtaining animal furs. The tremendous popu- larity of furs led to exploitation of the animals from which furs were obtained. In 1834, Astorretired from the fur-trading business to concentrate on investments in New York City. His estate, worth $20 million when he died, made him the wealthiest person in the United States. He left $400,000 to establish the Astor Library, now part of New York City Public Library. Glenn L. Swygart See also: Capitalism and resource exploitation; En- dangered Species Act; Forests; United States; Wild- life. Athabasca oil sands Category: Energy resources Where Found The Athabascaoil sands arelocated in theAthabascan basin of northeastern Alberta, Canada, near the Sas- katchewan border. The Athabasca River runs through the region—henceits name.Withtwo smalleroil sand deposits located elsewhere in the province, Alberta has a total of about 140,200 square kilometers of oil sands, the largest quantity in the world. There are also oil sands located outside Canada, primarily in Vene - zuela. Primary Uses With industrial processes, bitumen can be extracted from the oil sands and upgraded into light crude oil. Although the First Nations (Canadian aborigines) used the tarlike substance to waterproof and patch their boats, in modern times the oil sands have one commercial use: the production of crude oil. To pro- duce crude oil, an energy-intensive process is re- quired to extract the bitumen from the thick, sludgy, sandy substance. Bitumen is a heavy, viscous oil that can be industrially upgraded into synthetic crude oil, which inturnisrefined intogasoline and dieselfuels. Technical Definition The Athabasca oil sands consist of a tarlike mixture of about 80 to 85 percent sand and rich mineral clays, 10 to 12 percent bitumen, and 4 to 6 percent water. The valuable resource in this mixture is the bitumen. Bitu- men is a heavy, black, asphaltlike substance that has been pressurized underground for millions of years but not long enough to be concentrated into coal or light sweetcrudeoil. Nonetheless, it isa form of crude oil that can be processed for commercial use. Tech- nically, bitumen is a mix of petroleum hydrocarbons with a density greater than 960 kilograms per cubic meter. Description, Distribution, and Forms Oil sands are a viscous mix of hydrocarbons and can be found throughout the world but most prevalently in Alberta, Canada. While the Athabasca region has the largest quantity of oil sands, and the only surface quantities, there are also deposits buried in the Peace River and Cold Lake regions of Alberta. (Although the United States has some oil sand deposits, it also has massive quantities of oil shale, rocklike forma- tions containing crude oil that can also be refined at high industrial cost.) The oil sands contain a mix of sands, clays, water, and bitumen, but the bitumen, a form of heavy crude oil, is what gives oil sands their distinctive properties. Many ancient cultures made use of bitumen for its sticky, adhesive qualities. It was used as a sealant for boats, a building mortar, and an ingredient for mummification. In modern times, bi- tumen is valuable as a crude oil that can be refined into commercial petroleum. The Athabasca basin has the largest reserves of naturally occurring bitumen in the world. Semisolid at normal temperatures, the bi - tumen must be heated or diluted with hydrocarbons to make it flow through supply pipelines. The bitu - Global Resources Athabasca oil sands • 77 men is extracted through a steam separation process. Hot water is injected into the mined oil sands, causing the bitumen to float to the surface, where it can be re- covered. Thebitumen is then upgradedinto synthetic oil and petroleum products. History The First Nations knew about the oil sands deposits from ancient times and used the tarlike material to bind their canoes. Early Canadian explorers such as Peter Pond and Alexander Mackenzie wrote of the fluid bitumen pooling near the Athabasca River. In 1882, geologist Robert Bell surveyed the basin and oil fields. However, oil production did not become possi- ble until Karl Clark first developed a process for sepa- rating the bitumen from the sands. Clark’s process, developed between 1922 and 1929, relied on hot water and steam to turn the sand into a soupy sub- stance from which the bitumen could be extracted. In 1930, the Canadian government leased a large portion of the Athabasca basin for development to petroleum engineer Max Ball and his Abasand Oils company. Abasand’s separation process was primitive, however, and even by the 1940’s Abasand processed less than 20,000 metric tons of sand per year. The technological challenges of extraction re- mained daunting, but in the 1960’s the Great Canadian Oil Sands (GCOS) company built the first large-scale oil sands production plant, capable of pro- ducing about 24,000 barrels of synthetic crude oil per day. GCOS eventually became the Suncor Oil Com- pany, which remains the leading oil producer in the Athabasca region. In 1978, prompted by the oil em- bargoes of the 1970’s, the Syncrude consortium of oil companies built a second major oil sands plant, fol- lowed by Imperial Oil’s Cold Lake plant in 1987, Alsands Project Group’s facility in 1988, and Shell’s Albian Sandsmine in 2003. Inthe twenty-first century, oil production increased, with new technologies re- ducing the cost of bitumen extraction. Dozens of oil companies and industrial consortiums opened plants and increased supply. The proven feasibility of oil sands production led the U.S. Department of Energy to tabulate 32 trillion liters of oil reserves in the basin, second only to the reserves of Saudi Arabia. Obtaining Oil Sands The bulk of the oil sands are located near the surface and can be obtained through massive open-pit min - ing operations. Because of the heavy mineral clays that make up most of the sand, the operations use the largest shovels and trucks in the world to dig up and move the sands. Deposits that are located deeper— below 75 meters—are recovered by in situ methods, which include cyclic steam stimulation and steam- assisted gravity drainage. About 75 percent of the valuable resource, the bitumen, is obtained during the recovery. After the sand is processed and the bitu- men removed, Canadian environmental laws require the processed sand to be returned to the pit and the site restored to its original condition. Uses of Oil Sands The Athabasca oil sands represent one of the great oil reservoirs inthe world. Containinga potential 300 bil- lion barrels of crude oil, the oil sands of Alberta, rep- resenting 15 percent of the world’s oil, are second only to Saudi Arabia as potential oil reserves. There are currently four thousand agreements in Alberta between Canadian governments and oil companies for production of oil. More than 1 million barrels of oil are produced a day. Because of the thickness of the oil sands, it takes a tremendous amount of energy to produce oil flow. In the winter, temperatures in the Athabasca region fall to as low as −40° Celsius and the extraction machinery can easily freeze up and break down. Massive amounts of surface material are moved, sifted, and heated. Thus, two major issues must be ad- dressed for the world to exploit this resource: first, the high cost of extraction and, second,the impact on the environment. The profitability of the oil sands depends directly on the price of oil. While light crude oil flows easily from conventional oil wells, oil sand producers must expend fixed costs for mining and extracting the bitu- men and converting it to liquid crude. Thus the oil sands may be profitable if the price of oil is more than fifty dollars per barrel, for example, but noncompeti- tive below fifty dollars per barrel and completely un- feasible below thirty dollars. With new technology, production costs have been lowered to about thirty- three to thirty-seven dollarsper barrel, spurring an oil sands boom. As to the environment, the massive pro- cessing of oil sandsis bound to leave a certain scarring of the earth, despite Canadian restoration legislation. Oil sands production releases carbon dioxide, which is believed to contribute to the greenhouse effect. The recovery of bitumen itself requires the consump - tion of tremendous amounts of resources, mostly in the form of natural gas and water. 78 • Athabasca oil sands Global Resources In 2003, with the rise of oil prices, the oil sands op - eration became consistently profitable for the first time, and the three major mines—Suncor, Syncrude Consortium, and Shell Canada—began producing about 1.2 million barrels of synthetic crude oil per day. It was estimated that production could grow within a decade to more than 3 million barrels per day, making Canada one of the world’s leading oil- producing countries in the world. The oil companies engaged in the major production of oil from the Athabasca region include Suncor, Imperial Oil, Petro Canada, Marathon, Chevron, Occidental Petroleum, Canadian Natural Resources, Shell Canada, EnCana, British Petroleum, Husky, Total, UTS, Teck, Conoco Philips, Japan Canada Oil, Devon Energy, and various joint ventures. Cumulative investment in oil sands production in the first decade of the twenty-first cen- tury was estimatedto be about $70 billion,resulting in about 275,000 jobs. As of 2009, royalties to the Cana- dian government were close to $3 billion a year and oil sands production accounted for about 44 percent of Canada’s total output of crude oil. Howard Bromberg Further Reading Breen, David. Alberta’s Petroleum Industry and the Con- servation Board. Edmonton: University of Alberta Press, 1993. Chastko, Paul. Developing Alberta’s Oil Sands: From Karl Clark to Kyoto. Calgary: University of Calgary Press, 2004. Comfort, Darlene. The AbasandFiasco: The Rise andFall of a Brave Pioneer Oil Sands Extraction Plant. Fort McMurray, Alta.: Jubilee Committee, 1980. Ferguson, Barry Glen. Athabasca Oil Sands: Northern Resource Exploration, 1875-1951. Edmonton: Alberta Culture, 1985. Hicks, Brian, and Chris Nelder. Profit from the Peak: The End of Oil and the Greatest Investment Event of the Cen- tury. New York: John Wiley & Sons, 2008. Nikiforuk, Andrew. The Tar Sands: Dirty Oil and the Fu- ture of a Continent. Vancouver: Greystone, 2009. Tertzakian, Peter. A Thousand Barrels a Second: The Com- ing Oil Break Point and the Challenges Facing an Energy Dependent World. New York: McGraw-Hill, 2006. Web Site Athabasca Oil Sands Corp. http://www.aosc.com/ See also: Canada; Oil and natural gas distribution; Oil andnatural gas drillingand wells; Oilshale and tar sands; Petroleum refining and processing. Atmosphere Category: Ecological resources The atmosphere is the envelope of gases that surrounds Earth. Held in place by the attractive force of gravity, Earth’s atmosphere pervades all facets of the environ- ment. Almost every aspect of Earth’s system is depen- dent upon or markedly influenced by the behavior of weather systems spawned within the atmosphere. The atmosphere provides resources in the form of individ- ual gases, which can be separated industrially; it also directly affects other resources, most notably food re- sources. Background The composition of the atmosphere (excluding water vapor) below 80 kilometers is about 78 percent nitro- gen and 21 percent oxygen by volume (76 percent ni- trogen, 23 percent oxygen by mass). The remaining 1 percent includes all other dry gases, chiefly argon, carbon dioxide, neon, helium, krypton, hydrogen, and ozone. Water vapor, the mostvariable constituent of the atmosphere, typically occupies between 0 per- cent and 4 percent of the atmospheric volume. This mixture of gases is commonly referred to as “air.” The two principalconstituents of air aregreatly dis- similar in their chemical properties. While oxygen is an extremely active chemical, reacting with many sub- stances, nitrogen reacts only under limited condi- tions. The inert nature of nitrogen is believed to be the reason it came to be the atmosphere’s most abun- dant constituent. Volcanic outgassing in Earth’s early history is the likely source of its present atmosphere. Though nitrogen is a minor component of volcanic emissions, the lack of chemical reactions able to re- move it from the atmosphere allowed its concentra- tion to grow dramatically over time. Photosynthesis and, to a lesser degree, photodissociation of water by sunlight are believed to account for atmospheric oxygen. Carbon dioxide, aprincipal constituent of volcanic emissions, is also released into the atmosphere by the oceans, respiration, and fossil fuel combustion. Ar - Global Resources Atmosphere • 79 . effect. The recovery of bitumen itself requires the consump - tion of tremendous amounts of resources, mostly in the form of natural gas and water. 78 • Athabasca oil sands Global Resources In 2003,. Embargo Act of 1807, producing a profit of $200,000. Exploitation of human and natural re- sources was the inevitable result of Astor’s activities. American Indians, to whom the profit motive. extensive use of as- bestos. Production of asbestos in China has remained steady since 1995. China is one of the five leading pro- ducers ofasbestos but isperhapsits leadingconsumer. Imports of asbestos