Continuing a move toward greater concern with air quality, the U.S. government in 1986 lowered its standards for the amount of lead allowed in the air and banned solder containing lead.
As of January 1, 1986, continuing a trend that developed with the many air-quality acts of the 1960’s and 1970’s, the U.S. government set stricter standards for the amount of lead permitted in the air. At the same time, responding to extensive evidence of the harm associated with exposure to lead, specifically lead in paint, the government banned all lead in common solder.
By the late 1960’s, the dangers of lead in paint had become apparent to environmentalists. Children who licked or ate chips of peeling paint containing lead from their house walls—behavior most common in children in slum areas, where older, dilapidated walls often had cracked paint—were affected by lead poisoning. Some estimates placed the number of children suffering from paint-related lead poisoning at 225,000. When evidence of the problem became widely disseminated, several American cities enacted ordinances that forbade the painting of interior surfaces of buildings with lead-based paint.
Other efforts to regulate the amount of lead in the environment included the 1974 Safe Drinking Water Act,
Trace elements of lead from automobile emissions remained in the atmosphere, however. Lead particles that are inhaled travel to the lungs and are absorbed into the body at high rates. A small amount of inhaled lead could actually have a more serious effect than the consumption of a larger amount.
The use of lead in automobile fuels originated in 1923, and by the 1970’s, lead in the atmosphere had reached such levels that the average urban dweller in the United States absorbed about 16 micrograms. (Levels of lead poisoning considered dangerous for healthy males were 0.8 parts lead per million parts blood.) By 1971, the lead concentration in the average American’s blood stood at 0.2 parts per million, or one-fourth the amount considered hazardous. Concentrations of lead in city air sometimes reached extremely high levels. By 1971, Manhattan had average values of 7.5 micrograms of lead per cubic meter of air, and the lead content of some city dust approached 1 percent, an amount equal to the lead found in some ores. Grass along well-traveled roads was shown to have lead content up to 100 times higher than grass not exposed to automobile exhaust.
In 1970, primarily to reduce carbon monoxide and hydrocarbon emissions in the air resulting from automobile engines, Congress passed the Clean Air Act
Leaded fuel remained at the pumps for all the existing cars that required leaded gas. Auto high-performance enthusiasts resisted the less powerful engines that used unleaded fuel, and consumers at first avoided the unleaded variant. Gradually, however, unleaded gas replaced leaded, if only because engines, to accommodate catalytic converters, had to be changed from high to lower compression. By 1971, Detroit had equipped most of its major cars with low-compression engines in anticipation of the new standards, and President Richard M. Nixon ordered the federal government to operate all of its gasoline-powered vehicles on unleaded gas.
In addition to the provisions for unleaded fuel, the government banned all solder containing lead to reduce both manufacturing and direct-exposure harm from lead in the workplace and in the home. Solder, a molten form of lead that joins two other metals together, was often used in place of welding by plumbers and automobile manufacturers (which applied solder to car body fillings). The use of solder in canning food caused particular problems: One study found that such solder accounted for up to 28 percent of dietary lead, the most dangerous form of lead intake. It was found that other alloys could be substituted for the lead in solder without reducing the quality of the results.
The U.S. government’s efforts to regulate air quality conflicted with other, simultaneous efforts to improve automobiles’ gas mileage and maintain competition among automakers. The auto industry had to meet clean-air standards and satisfy the requirements set by the Environmental Protection Agency (EPA), but car manufacturers were not allowed to engage in cooperation to accomplish that, as that would have been a violation of the Justice Department’s standards against collusion. Automobile manufacturers also had to meet increasingly strict safety standards administered by the National Highway Traffic and Safety Administration while simultaneously trying to improve fuel efficiency to meet mandates from the Department of Energy.
Among the separate requirements of the 1970 Clean Air Act that affected emission of pollutants, engines had to meet a “cold start” standard of low emissions during the first thirty seconds of operating time. This was difficult to achieve because the reciprocating parts of an engine could not be lubricated in so short a time. Meeting that standard cost the U.S. industry billions, yet cars imported from Japan were exempt from the standard. Japan, which faced worse emission-related pollution than did the United States, rejected the “cold start” requirement when formulating its domestic laws.
Following congressional hearings in which representatives from the auto industry explained their plight, EPA administrators frequently delayed implementing one or more of the clean-air standards. Nevertheless, by 1990 lead levels in the atmosphere across the United States had declined by 96 percent since 1970 as a result of the disappearance of leaded-gasoline-fueled auto engines.
Longer-term effects, however, could not be as easily measured. Certainly American car manufacturers failed initially to approach the problem from a design standpoint, which would have required a new approach to the internal combustion engine. Instead, in the words of Car and Driver columnist Brock Yates, automakers attempted to “tack exhaust emission plumbing on existing large-displacement engines.” That resulted in poorly performing large engines. Because of the lower performance and slower acceleration of unleaded engines in the early years, motorists wasted fuel by “gunning” their engines. It is conceivable that the poor combustion may have resulted in a greater total volume of emissions (although with fewer particulates per cubic meter of air) than before.
Eventually, the automobile industry solved most of these problems by adopting higher-performance engine designs that had been used for years by race cars. Overhead camshafts, fuel injection, turbochargers, and electronic ignition replaced standard internal camshafts, carburetors, and distributors and enabled smaller engines to produce much higher horsepower. By the 1990’s, a new wave of smaller but powerful cars had been released.
The effects of the many pollution, fuel-efficiency, and mileage standards imposed in the United States were difficult to assess. Independent studies repeatedly confirmed that there were almost no savings in fuel or lives from the widely publicized attempt in the 1970’s to save fuel by lowering highway speed limits to fifty-five miles per hour. By 1981, however, the many air-quality control acts had resulted in the reduction of hydrocarbons and carbon monoxide to 4 percent of their 1960 level. This virtually eliminated automobile emissions as a factor in air pollution in the United States. Other nations that allowed leaded-gasoline-fueled vehicles, however, continued to affect global levels of lead in the atmosphere.
Nature, too, is a small contributor to lead levels in the atmosphere. In 1980, studies showed that dusts, volcanic output, vegetation, sea spray, and natural fires produced about 5 percent of the lead in the air. Even if lead additions to the atmosphere could be removed entirely from the processes that mine and manufacture lead, global emissions would continue from natural causes.
Extensive use of lead in manufacturing continued, however. Ball bearings continued to constitute a major use of small amounts of lead, and lead alloys continued to be used in bearing material and in the production of printing metals. Several building materials continued to be made with lead, including lead roofing and sheeting, because lead’s softness and malleability make it easy to work with at normal temperatures and yet durable; the density of lead sheeting makes it particularly suitable as a barrier to airborne sound and for use in industry that requires noise reduction from engines.
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Craig, Paul P. “Lead, the Inexcusable Pollutant.” Saturday Review, October 2, 1971, 68-70, 75. An early exposé on the dangers of lead in paint and in the atmosphere. -
Featherstone, Joseph. “The ’Silent Epidemic.’” The New Republic, November 8, 1969, 13-14. One of the first articles to appear in a popular magazine that described the various attempts by citizens and the federal government to address the dangers of lead in paint. -
Lansdown, Richard, and William Yule. Lead Toxicity: History and Environmental Impact. Baltimore: The Johns Hopkins University Press, 1986. Traces the health problems associated with lead in paint, industry, and automobile exhaust, and includes studies on the effects of lead on intelligence and overall health. Also discusses exposure to lead solder, lead manufacturing and mining, and lead caused by natural forces. -
MacAvoy, Paul W. Industry Regulation and the Performance of the American Economy. New York: W. W. Norton, 1992. Does not deal specifically with lead in the atmosphere, but presents a great deal of information on air pollution in general and the effects of government regulation on industrial productivity and costs. -
McCance, Kathryn L., and Sue E. Huether. Pathophysiology: The Biologic Basis for Disease in Adults and Children. 5th ed. St. Louis: C. V. Mosby, 2005. Comprehensive text includes discussion of the effects of lead on the nervous system. The schematic presentation of the effect of lead in children is particularly well presented. -
Needleman, Herbert L., ed. Human Lead Exposure. Boca Raton, Fla.: CRC Press, 1992. Collection of technical articles addresses the effects of continued human exposure to lead and the adverse effects of lead poisoning. Includes bibliographic references and index. -
Warren, Christian. Brush with Death: A Social History of Lead Poisoning. Baltimore: The Johns Hopkins University Press, 2000. Explores the social costs of lead exposure throughout U.S. history. Describes the shifts in attitudes and changes in technologies that came about after Needleman’s findings were published. Includes index. -
Yates, Brock. The Decline and Fall of the American Auto Industry. New York: Empire Books, 1983. Examines the automobile industry’s attempts to meet environmental and safety standards enacted by the federal government. Sympathetic to the automobile industry, but critical of Detroit’s strategy for dealing with the reality and perception of pollution.
Automakers Introduce the Catalytic Converter
Clean Air Act Is Revised
Scientists Correlate Lead Exposure with Intelligence
United States Makes Pollution Prevention a National Goal
U.S. Congress Approves More Clean Air Act Amendments