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Lead in the Americas: A Call for Action (1996)

Chapter: Session D: Case Studies of Interventions

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Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
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SESSION D

Case Studies of Interventions

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
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Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
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INTRODUCTION: CASE STUDIES OF INTERVENTIONS

DAVID RALL*

The task of reducing lead exposures and preventing lead poisoning across the Americas seems a daunting task. This session highlights four case studies of interventions in different sectors. The first describes a successful voluntary industry initiative in Mexico to remove lead solder from the canning process. The second presents an example of government regulation—in this instance, the U.S. Clean Air Act—that dramatically reduced population lead levels in the United States. The third case study explores the role of international organized labor—in this case the U.S. Carpenter's Union—in educating and training workers about lead poisoning and describes the union's efforts to work with government agencies to ensure stricter protective policies for workers and their families. The final case study describes the role of community activism and education in empowering local communities in Mexico to design and implement focused public health programs to reduce lead exposure in their populations.

What these four case studies illustrate is that successful control and prevention strategies require the involvement of people and organizations at all levels of society, from the federal sector down to the grassroots or community. Lead poisoning is a problem that directly affects people at all levels of society. Its solutions must, therefore, also be shared.

*

Retired, National Institute of Environmental Health Sciences, USA.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
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VOLUNTARY INDUSTRY INITIATIVE: REMOVAL OF LEAD SOLDER FROM CANS

ALFONSO DE LEÓN*

In 1992, the metallic containers industry in Mexico stopped producing tin cans with lead soldering as food containers, substituting instead a process that closes tin cans with electrical solder. Mexican public health authorities are now interested in determining whether a quantifiable reduction in population blood lead levels, especially in children, has occurred as a result of this voluntary industry change.

The National Chamber for Metallic Containers of Mexico represents more than 85 percent of steel tin can and 100 percent of aluminum tin can production, making it the leading manufacturer of metallic containers in Mexico. The process leading to the total elimination of lead soldering in food cans was begun as a voluntary initiative by industry, although the increased pace of change in the latter phases of conversion was dictated by external events. This process is described briefly below.

Metallic containers have been used to hold and conserve food for more than 180 years. In the beginning, tin was used in soldering, but it resulted in little flexibility and a fragile seam. Lead rapidly replaced tin in solder because it is a ductile material that easily adheres to the tin plate and can be mixed with the tin to produce a more flexible and less fragile soldering. At one point the solder commonly used contained 90 percent lead and 10 percent tin. Such soldering was universally adopted and, with it, many billions of cans were produced globally, without an understanding that lead in external soldering posed a public health hazard.

When medical and public health authorities began to acknowledge concerns about the effects of lead exposure on human health, attempts were made to identify the different sources of the metal. Leaded gasoline, paints, and ceramicware glazes and food cans containing leaded solder were rapidly identified as important sources.

*

National Chamber for Metallic Containers, Mexico City, Mexico.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

Manufacturers of metallic containers had already began, by the late 1970s, to substitute lead soldering with electric soldering. This change was instituted for reasons apart from public health concerns about lead, which remained largely unknown at the time. The main motives for converting to electrical soldering were to have a cleaner production process, greater productivity, and a larger surface area on the cans for the purposes of advertising (leaded seams are broader than electrically soldered seams). Mexico adopted the electrical soldering technique, despite the many lead soldering production lines that still had many years of usable life and the $1.2-2.0 million investment that was required to refit production lines. This change was an unusual one for Mexico, which does not usually afford itself the luxury of getting rid of production equipment that is still considered useful.

At the beginning of 1991, a strong popular movement against lead in the environment was organized in Mexico City. The metallic container industries became involved in this movement, along with other lead industries. As an outcome, ecologists, united with health authorities, insisted that the electrical soldering substitution process that had been under way for over 10 years be abruptly accelerated. We cannot deny that moments in the ensuing deliberations were amusing.

The industry's basic argument in 1991 against an abrupt acceleration in the substitution process was based on the following: (1) in 1979 the industry voluntarily initiated a gradual substitution of production lines that utilized lead solder; (2) the cost for substituting each line was too high to warrant wholesale, rapid substitution; (3) until research proved that inward migration of lead from the external soldering of tin cans was contributing to the amount of lead in canned foods, accelerated action was premature; and (4) the recommended threshold for lead in foods was still subject to debate.

To support industry's argument, we noted U.S. FDA reports that indicated similar voluntary changes occurring at the same pace in the U.S. metallic container industry. According to these reports, in the early 1980s, 90 percent of tin cans produced in the United States had leaded solder; by the 1990s, the proportion had dropped to approximately 4 percent and was expected to decrease even more in the coming years. Clearly, industry in two major markets was voluntarily making changes, and the demand that the Mexican sector suddenly accelerate its rate of conversion—at considerable additional cost—was unfair.

The FDA, to my knowledge, has not yet been able to establish legislation totally prohibiting the use of lead soldering in tin cans for food. In 1994, for

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

example, 139,000 million tin cans were produced in the United States; of these, 20,000 million were three-piece tin cans used for food. Assuming that only 2 percent of these had lead soldering means that 400 million tin cans would have still contained lead soldering. It is our industry's belief that, in the United States, voluntary action by industry will eliminate lead soldering in the near future without the need for legislation.

Returning to the story in Mexico, none of the arguments listed above swayed the necessary Mexican decisionmakers. Health authorities, pressured by ecologists, continued to demand immediate conversion to electrical soldering. This activity culminated in the 5 July 1991 signing of the “Actions for the Integral Solution of the Problems Related to Lead Content in Products that Could Constitute a Risk for Health and Ecosystems” in Mexico City. The National Chamber for Metallic Containers agreed in this document to accelerate the transformation of all of its production lines in order to eliminate lead from the soldering process. We were given a very short time to complete the necessary changes. This posed special problems—for example, the machinery for producing electrical soldering was manufactured in Europe and required 10 to 12 months for delivery. Our organization was also required to close 15 new production lines. Recognizing the difficulties of implementing wholescale change in a short time frame, the Mexican government generously granted our industry 18 months to fulfill our task.

At that time, as an active member of the “Normalization of the Metallic Food and Drink Containers Subcommittee, ” I began work with colleagues on the elaboration of a preliminary program to regulate the types of solder that would be permitted on tin cans for food. On 2 June 1993, a text of the program was made available and accepted by both the private and public sectors. The health secretary in the Office of the General Management of Environmental Health visited our plants to verify that lead soldering had effectively been eliminated from the soldering process.

Finally, on 11 November 1993, the report of the subcommittee was published in the Diario Oficial (Mexico's largest newspaper). According to the law, 90 days were given to interested parties to express comments and concerns about the proposed project. On 8 February 1994, the secretary of health held a meeting to analyze the commentaries given. Revisions were made, and the final text revised. On 14 November 1994, the Norma Oficial Mexicana (Official Mexican Norm) NOM-002-SSAT-1993 “Metallic Containers for Food and Beverages: Seal Specifications and Sanitary Requirements,” was published in the Diario Oficial. The norm prohibits the use of

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

lead soldering in metallic containers for food. The norm is also applicable to imported products, serving as a way to prohibit lead-soldered cans from entering the country. Helped by a loan of $35 million, our industry had fulfilled its commitment to change to lead-free soldering in the 18 months accorded us.

One aspect of Mexico's experience that was not given the attention it deserved was the unfilled need for assistance to workers who had been poisoned through occupational exposure to the lead soldering process. On many of our old production lines, the containers of melted solder sat open, generating lead fumes. Systems of absorption and filtration existed for these emissions, but were rarely adequate. In addition, masks usually given to workers were frequently not used because the workers complained of hindered breathing. As a result, cases of lead poisoning were common, and many of these workers still require medical attention.

Our organization also believes that food containing lead before processing and canning should be given careful attention. Tuna, for example, because of its metabolism, has a tendency to absorb heavy metals such as lead, cadmium, mercury, and arsenic. The National Institute of the Consumer (INCO) of Mexico on one occasion reported large amounts of canned tuna containing lead above the threshold limit established at that time. The cans in which the tuna was stored were of the two-piece variety that did not contain solder of any kind.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
A CASE STUDY IN GOVERNMENT REGULATION: U.S. GASOLINE LEAD REDUCTION

ROBERT A. SCALA*

This paper will trace a successful story of government intervention to reduce the risk of airborne lead intake and possible lead poisoning. The story is told from the perspective of the U.S. Environmental Protection Agency (EPA), the main government agency involved.

Lead had been used as an additive in gasoline from the 1920s to boost octane and to provide lubrication for certain engine parts. Tetraethyl lead and tetramethyl lead, both high in octane value, lubricate intake and exhaust valves and help to reduce engine knock (EIA, 1992). Over time the use of additives became increasingly widespread, and the amount in fuel increased as octane demand increased. Although the limit for lead in gasoline was approximately 4 grams a gallon, a usage level of 2.5 g/gal was more typical. Because of increasing health and environmental concerns over atmospheric lead, lead reduction began with the 1970 Clean Air Act, which authorized restrictions on the use of lead in gasoline. In 1970 there were almost 90 million passenger cars registered in the United States, and motor gasoline consumption was 5.78 million barrels daily (approximately 915 million liters daily). Under the Clean Air Act, the U.S. EPA was authorized to regulate fuels and fuel additives. Unleaded fuels also appeared in the early 1970s. Auto manufacturers were required to design and build vehicles that could operate on unleaded fuels or low-lead fuels, and a schedule was set for the reduction of lead levels in leaded fuels.

Before the Clean Air Act, the EPA had strong concerns about the potentially harmful effects of lead, but was unable to persuade the scientific community or industry that airborne lead represented a health hazard outside the workplace. Under the Clean Air Act, the EPA was given the authority to control airborne lead attributable to motor vehicle emissions for reasons beyond potential health hazards. A 1980 National Research Council publication outlined a model for regulatory decisionmaking re-

*

Retired, Exxon Biomedical Sciences, Inc., Rehoboth Beach, Delaware.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

garding potential health hazards of environmental agents (NRC, 1980). There were nine steps:

  1. Identify sources of lead and pathways of environmental transfer;

  2. Identify specific human populations with exposure to lead;

  3. Estimate the level of exposure to lead by each environmental pathway for each specific population;

  4. Establish the association between exposure to lead and the level of lead in the body for each specific population;

  5. Establish the association between the level of lead in the body and biological change caused by lead for each specific population;

  6. Estimate the upper limit of nondetrimental biological change for each specific population and the level of lead in the body associated with that degree of biological change;

  7. Identify and describe alternative control strategies;

  8. Apply risk-benefit, cost-benefit, and other considerations, compare alternatives for control, and decide what is an acceptable level of lead in the environment for each specific population; and

  9. Evaluate the process and the decision.

SOURCES AND PATHWAYS

Of greatest interest with respect to motor gasoline is its contribution to airborne lead. The amount of lead in the air appears to be related in large measure to the amount of lead in fuel. Leaded fuels generated 24,000 µg/m3 of lead at the tail pipe in the era before lead phasedown (NRC, 1993). Typical lead levels in urban environments in the 1970s were in the range of 0.5 to 10 µg/m3, and perhaps 90 percent of this is attributable to lead from gasoline. Most lead is emitted as halides and oxides, but virtually all of it is eventually converted to the sulfate. Most of the lead is deposited near the vehicular source. Particles with diameters in the range of 10 µm are deposited over a broad distance, and there is long-range transport of particles with a diameter of less than 0.1 µm for over a month (NRC, 1993). Lead is widely distributed in the body, with a preferential uptake by bone.

EXPOSED POPULATION

From the outset, EPA held that leaded gasoline was a source of air and dust lead that could be reduced readily and significantly in comparison with other sources. It also held that young children in the age range of 1 to 5

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

years should be regarded as a group sensitive to lead exposure (EPA, 1978). The third link in the EPA chain of logic is that contaminated dust and dirt from motor vehicle exhausts are the most important exposure routes for children (EPA, 1973). The health status of children was the principal driving force for the regulation of the lead content of fuels. As late as 1984, about 6 million children and 400,000 fetuses in the United States were exposed to lead at concentrations that placed them at risk of adverse health effects, defined as blood lead levels of at least 10 µg/dl (NRC, 1993).

EXPOSURE-BODY BURDEN ASSOCIATION

The EPA put great emphasis on the work of Azar et al. (1975), which showed a ratio of lead in the air to lead in the blood of 1:1.8 at airborne levels of 1.5 µg lead/m3, where lead in blood was expressed in the usual terms of µg/dl (micrograms lead per deciliter of blood). The work was in adults, not children. the EPA holds that children have a greater net absorption and retention of lead than adults. The agency assumes that the air-lead to blood-lead relationship for this sensitive population exposed to lead in ambient air equals or exceeds the relationship for adults. The literature also suggests (ACGIH, 1991) that this relationship is nonlinear with concentration in air. Yankel et al. (1977), using children living near a smelter, found an average ratio of 1:1.9. Some of the nonlinearity in the relationship is explained by particle size changes with concentration, 24-hour vs. 8-hour exposures, and certain kinds of avoidance behavior by workers.

BODY BURDEN-EFFECT ASSOCIATION

Preceding presentations have discussed the issues centering on clinical and subclinical effects of various body burdens of lead, expressed either in blood lead levels or tissue concentrations. the EPA emphasized minimizing lead burden. The agency position was that air lead contributed to general population lead exposure and that airborne lead levels below 2 µg/m3 affect blood lead levels. With the promulgation of a National Ambient Air Quality Standard for Lead in 1978 (EPA, 1978), the EPA stated that for the sensitive population previously defined (children ages 1–5 years), a blood lead level above 30 µg/dl was associated with an impairment in heme synthesis in cells, as indicated by an elevation in erythrocyte protoporphyrin. This finding was judged by the EPA to be adverse to the health of chronically exposed children. the EPA also declared that there were a number of other adverse health effects associated with blood lead

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

levels above 30 µg/dl in children, as well as in the general population. Three systems appear to be most sensitive to the effects of lead: the hematopoietic system, the nervous system, and the renal system. Inhibition of enzymes systems has a threshold as low as 10 µg/dl; at the other end of the scale, permanent, serious neurological damage or death have thresholds approaching or exceeding 80 to 100 µg/dl in children.

CONTROL STRATEGIES AND OPTIONS

The EPA acknowledged that the lead exposure problem arose from a combination of sources, including food, water, air, leaded paint, and dust. The contribution of each source varies depending on the environment, bioavailability, and individual exposure and uptake. Reducing lead from all sources would improve health; the EPA, however, viewed lead in gasoline as a source of air and dust lead that could be readily and significantly reduced.

The first steps taken to reduce lead in gasoline in the United States resulted from the introduction of the platinum-based catalytic converter. This device, which reduced emissions of polycyclic aromatic hydrocarbons and other pollutants from gasoline, was damaged by lead. Starting in 1973, it was necessary for EPA to ensure a supply of lead-free fuels for new cars equipped with catalytic converters. In 1978, EPA moved to evaluate the public health benefits of removing lead from gasoline in order to reduce lead in the ambient environment. The initial regulations set quarterly limits on allowable amounts of lead used by refiners and permitted averaging this amount across all grades of gasoline produced. It was assumed that the natural replacement of older vehicles with cars requiring unleaded fuels would result in the programmed reduction of lead in gasoline, without further intervention by government. By 1982, however, two trends were recognized that prevented this natural reduction: first, a substantial number of motorists continued to use leaded gasoline because of its lower pump price (misfueling); and second, since the allowable content of gasoline was defined as the average of all fuels produced, the per gallon content of leaded gasoline could actually increase as the fraction of leaded/unleaded decreased. Because of these two phenomena, the EPA took further regulatory action to ensure the phasedown of lead in gasoline in 1983–1985. Simply by changing the basis of calculating allowable levels of lead in gasoline from the total fuel base to leaded gasoline only, EPA caused a substantial decrease in the amount of lead used in gasoline. In 1990, the U.S. Congress mandated the eventual phaseout of lead in gasoline in the United States.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
ENVIRONMENTAL IMPACT

There were some environmental consequences of the motor gasoline lead phasedown. One was misfueling, or using leaded fuel in a vehicle designed to use unleaded fuel. Misfueling was found in about 6 percent of vehicles in the inspection and maintenance programs.

Of interest is how much lead use was reduced by the phasedown of leaded fuels. With the introduction of the catalytic converter in 1973, the next 10 years showed an increase in unleaded gasoline use. By 1983, unleaded fuel was just over 50 percent of the total gasoline market in the United States, and by 1995 it represented almost the entire market. the EPA estimated a 34 percent reduction in lead use over the interval 1983 –1990, with a savings of almost 130,000 tons of lead (EPA, 1982c). Natural Resources Defense Council figures estimate more comprehensible figures. Lead used in motor gasoline in the United States totaled 243 thousand metric tons in 1971; 309 thousand metric tons in 1976; and 138 thousand metric tons in 1981. When the phasedown really took effect, lead use was reduced to 7.1 thousand metric tons in 1986 and 4.4 thousand in 1992 (NRDC, n.d.).

BARRIERS TO CHANGE

Companies that sold lead additives for gasoline were faced with the prospect of seeing their business virtually vanish over a period of just a few years. They were in the position of buggy whip makers at the beginning of the automotive era. The prudent companies diversified. There was also some reasonable resistance on the part of auto manufacturers. Lead in gasoline not only provided octane value but was also a lubricant for engine parts. The presence of lead prevented valve seats from being “beaten in” because the relatively soft lead deposits provided a form of cushion. Work on metallurgy had to be done as part of the lead phaseout. In the end, unleaded and low-lead gasolines were widely available on schedule.

ECONOMIC ANALYSIS

The EPA examined the costs of lead phasedown in terms of reduced lead use (EPA, 1984). The agency estimated that the marginal cost of removing lead from gasoline was about U.S. 1¢ for each gram of lead. EPA also found that lead removal presented a positive cost-benefit. The benefit fell into three

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

categories: savings on vehicle maintenance, reduced misfueling, and reduced health care costs. For the period 1986–1988, the projected 0.1 gram per gallon for leaded gasoline would produce annual benefits over costs of greater than $1 billion ($1,000 million).

MEASURES OF SUCCESS

The findings of the National Health and Nutrition Examination Surveys II (NHANES II), which covered the period of 1976–1980 (NRC, 1993), used a stratified multistage probability cluster sample of U.S. households. Blood lead levels were measured for persons aged 6 months to 74 years, and almost 10,000 samples were used. As Figure 3-8 depicts, there was a striking

Figure 3-8. Lead used in gasoline production and average NHANES II blood lead (February 1976-February 1980). Source: Reprinted, with permission, from J.L Annest, “Trends in the bood lead levels of the U.S. population: The Second National Health and Nutrition Examination Survey (NHANES II) 1976-1980,” in Lead Versus Health, M. Rutter and R.R. Jones, eds., New York: John Wiley & Sons. ©1983, John Wiley & Sons, Ltd.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

association between declining lead levels in gasoline in the period of 1976-1980 and the subsequent decline in blood lead levels in the U.S. population. Although the choice of scale for each of the vertical axes in Figure 3-8 permitted the dramatic overlay of the declines in amount of lead in gasoline and blood lead levels, one is hardpressed to deny that the association is not a correlation. For NHANES III (Pirkle et al., 1994), the survey covered the period 1988-1991, with over 12,000 blood samples from a population whose ages ranged upward from one year. The mean blood lead level of persons aged 1-74 years decreased 78 percent, from 12.8 to 2.8 µg/dl, a drop of 10 µg/dl. Comparable percentage decreases were seen for non-Hispanic white and non-Hispanic black children aged 1 to 5 years. There was a decrease in the prevalence of blood lead levels equal to or greater than 10 µg/dl, from 85 percent to 5.5 percent for non-Hispanic white children and from 97.7 percent to 20.6 percent for non-Hispanic black children. The authors attributed the majority of this decrease in blood lead levels to the virtual removal of lead from gasoline and the reduction of lead in soldered cans (Pirkle et al., 1994).

SUMMARY

Government intervention in the form of control regulations can be successful in reducing the body burden of lead in the population as measured by blood lead levels. This reduction in burden surely represents a comparable reduction in the risk of lead-related diseases and dysfunctions.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
ACTIVISM: THE ROLE OF ORGANIZED LABOR IN PROMOTING A HEALTHY WORKPLACE

JOHN D. REPKO*

The United Brotherhood of Carpenters, with about 550,000 members in North America, has members who work in all aspects of the trade, including general construction, renovation, and repair, as well as working on bridges and other steel structures. Our members work in buildings and on steel structures known to contain lead-based paint. Piledrivers are frequently exposed to lead-based paint when applying acetylene torches to bridges undergoing renovation.

HEALTH EFFECTS

Lead intoxication is a continuum, in which the adverse effects are expressed at the cellular, organ, or whole organism level, depending on the dose (Silbergeld et al., 1991). There is no magic level; the toxic effects of lead are evident when increased absorption begins.

In addition to working in an occupation that exposes a worker to lead, the worker may come to the job with exposures to lead from the home or living environment. Whatever standards are ultimately established for workers, they must provide for this margin of prior exposure.

“Take-home” lead is also a concern. Recently the National Institute for Occupational Safety and Health (NIOSH) (Sussell, in press) reported 62 incidents worldwide of paraoccupational, or “take-home” lead exposure. Industries with reported paraoccupational lead exposures included lead smelting, battery manufacturing and recycling, radiator repair, electrical components manufacturing, pottery and ceramic production, and stained glass making.

*

United Brotherhood of Carpenters, Washington, D.C.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
INTERVENTION STRATEGIES

The Carpenters' general approach to intervention is very much proactive. Generally, our approaches fall into four categories: (1) education and training, (2) collaboration with scientists involved in occupational health research, (3) support for occupational and environmental health standards and regulations, and (4) what we call, “dealing an honest hand.”

Education and Training

Health and safety education for workers about the occupational dangers of lead exposure is an important part of both apprenticeship education and the ongoing training of the journeyman. The U.S. Society for Occupational and Environmental Health, for example, developed a document that was used extensively by the EPA in the development of regulations governing required curriculums for lead-based paint worker and supervisor training (SOEH, 1993). This document and the training programs it has engendered have been effective among our membership in preventing work-related diseases and injuries, keeping workers up-to-date, and helping workers develop an attitude and willingness to practice prevention.

Collaborative Research

The Carpenters have collaborated on many research activities designed to identify health problems arising from workplace exposures to lead. In 1991, Dr. Irwin Selikoff, who headed Mount Sinai Environmental Sciences Laboratory, in collaboration with NIOSH and Harvard Medical School, conducted the first membershipwide screening of Carpenter workers. A subgroup underwent an even more detailed study, including questionnaires on lead exposure history, blood lead testing, and in vivo measurement of bone lead levels. The study found that age was the dominant predictor of both tibia and patella bone lead. Demolition, carpet laying, and alcohol ingestion were also significant predictors of bone lead (Watanabe et al., 1994). The authors concluded that the data reflect a subclinical effect of bone stores of lead on hematopoiesis and that this effect is the first epidemiologic evidence that bone lead may be an important biologic marker of ongoing chronic toxicity. The researchers also found that the differences in concentrations of bone lead between the tibia and patella are suggestive of ALAD-2-associated pharmacokientic effects. Further, they suggest that subclinical lead-associated kidney dysfunction is found with relatively low

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

current blood lead concentrations, and that the ALAD-2 genotype may be an additional modifier of this effect (Smith et al., 1995). The Carpenters have also worked with Dr. Selikoff's successors, a network of devoted scientists, by promoting continued study of the membership.

These studies demonstrate that information useful to workers' health can be obtained when workers and unions collaborate with their scientific and academic colleagues. By providing additional evidence of lead's toxicity at very low blood and bone levels, such studies can promote changes in occupational standards that better protect the health of workers.

Occupational and Environmental Regulation

Numerous standards have been set for lead in both the occupational and nonoccupational setting. Some standards set limits on allowable concentrations of lead in the ambient air or workplace air, as well as other environmental compartments, and some standards are based upon biological monitoring. In the workplace, both airborne lead and biomarkers are components of preventing lead poisoning in most national systems.

The U.S. occupational lead standard was promulgated in 1978, one of the first de novo standards developed by the Occupational Safety and Health Administration (OSHA), without reliance on earlier guidelines proposed by the American Council of Government and Industrial Hygienists (ACGIH). the OSHA lead standard was noteworthy in that it proposed both a limit on airborne lead in the workplace (50 microgram/m3) and a mandatory program of biological monitoring in most work settings. In addition, the OSHA standard protected worker health and employment rights by establishing a medical removal program: workers whose blood lead levels exceeded the standards were temporarily shifted to jobs without lead exposure with no loss of pay, benefits, or seniority. This approach was intended to change the incentives in the labor management relationship, to encourage employers to reduce lead exposures, and to protect workers from job termination or loss of income.

In the United States, occupational standards cover most, but not all, workers exposed to lead. In 1993 the lead standard was finally extended to workers in the construction industry, who are often highly exposed to lead during repair and maintenance of steel structures (which may still be painted with lead-based paints); demolition workers; and workers involved in abating lead hazards in housing. Small workplaces are still imperfectly covered, and some of these, such as battery repair shops, may be sources of intense exposure that not only pose problems for workers, but

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

can also be sources of contamination to workers' homes and releases to the environment (Matte et al, 1989b; Nunez et al, 1993). In several countries of the Americas, informal “cottage industries,” such as recycling facilities, are almost wholly outside any regulatory surveillance, as demonstrated in a report from Tijuana, Mexico (Leung, 1988).

Dealing an Honest Hand

Historically, organized labor and the lead industries have not had an easy relationship. A number of incidents illustrate their lack of cooperation. The events surrounding the American Smelting and Refining Company (ASARCO) lead smelter emissions in El Paso, Texas, in the late 1960s (Repko et al., 1978) and the Bunker Hill smelter in Kellog, Idaho, in the 1970s (EDF, 1992) are two such examples. The lead industry also consistently attacks studies that demonstrate a causal relationship between lead exposure and adverse health effects in order to counter this increasing body of evidence. Another industry approach is to claim simply that lead is not a problem and that nothing, therefore, needs to be done about limiting exposures to the metal.

As a result, labor has had to consistently challenge the positions taken by the lead industry. NIOSH's legal right of entry, for example, has been used to conduct health hazard evaluations in the workplace. Because of the active involvement and support of labor, however, the lead industries have never won a major victory over the EPA or OSHA, the government organization most responsible for worker health.

In response, there is a current effort by industry to shift its worksites into international markets where regulation is less restrictive or does not exist. Moreover, environmental advocacy groups or scientific communities may also be absent or small in a number of these areas. Workers all over the world are increasingly under attack by corporate and financial interests who use the globalization of products such as lead as a lever to restrict worker rights and to lower workplace standards. It is the responsibility of labor to fight against this trend.

CONCLUSIONS

Workers continue to be poisoned by lead on the job. Members of labor groups or health professionals can help reduce worker exposure in several ways:

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
  • Worker education is the first step to prevention. Workers have the right to know. An informed workforce increases its control over its exposure. Inspectors and government officials responsible for workplace health and safety must also be well-trained and informed about lead hazards.

  • International and national protective standards for workers should be widely adopted across the Americas, but these should not necessarily copy those of the United States. Labor and workers should have an opportunity to establish stringent standards for lead exposure consistent with new scientific evidence that was not available or not used when the United States first set its standards.

  • Existing environmental or workplace standards that limit workers' exposure to lead must be enforced. To adequately enforce regulations will require a coordinated effort by an educated workforce, competent inspectors, an effective judicial system, and policymakers who can support the courts and the inspectors.

  • Productive collaborations among unions, scientists, occupational health professionals, and academics should be fostered.

  • Union officials should be informed of the importance of occupational health and encouraged to raise the level of workers' health to the same level of concern in contract negotiations that is routinely given to economic issues.

  • Finally, persist, and don't give up. Whenever new ways of making a dollar, peso, real, other currency involve new hazards, those who work to protect worker health are playing “catch up.” Remember that it is always the workers who pay first and worst.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
COMMUNITY ACTIVISM AND EDUCATION: ACCESS TO NEW KNOWLEDGE AS A BASIS FOR COMMUNITY EMPOWERMENT

CHRISTINA VON GLASCOE, M.D., PH.D. *

If people in the developing world are to have radically improved lives, it is first of all necessary to teach them to be dissatisfied with the present situation and at the same time make them appreciate how they can work towards a better future.

Bidwell, 1988

Environmental health issues are of recent concern at the northern border of Mexico, but to date have not been addressed in a concerted fashion by either community interest groups or public health authorities. For example, public health authorities and two major nongovernmental organizations (NGOs) working in primary care and family planning in Tijuana, Mexico, have yet to incorporate environmentally driven concerns such as lead poisoning into their regular health activities. Nevertheless, there are indications that lead poisoning and other environmental health concerns are gaining visibility at the local level in Mexico, as they are elsewhere in the Americas.

A major requirement in creating the necessary infraculture for community-based action is the need to increase popular knowledge and public awareness of environmental health hazards and the steps that can and should be taken to reduce these hazards. An example of such work is provided in this paper. Ways to incorporate such knowledge into the cultural horizon of a community under environmental health stress are highlighted.

DEFINING THE CULTURAL HEALTH HORIZON

Anthropologists interested in health recognize that community members practice a wide range of activities related to public health, with or without the direction of health authorities. In any community there coexist interpretations of an official and a traditional system of dealing with public health threats, and these do not necessarily influence each other. In order to deal

*

North Border College, Tijuana, Baja California.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

effectively on a grassroots level, it is necessary as a first step to define the “cultural horizon” of the community. Broadly defined, the cultural horizon is the wide range of public health activities practiced by community members, with or without the direction of the health authorities. Thus, the development of effective community strategies to reduce or prevent lead poisoning will depend not only on information on the sources of contamination and number and distribution of cases identified, but also on being able to convey that information in a manner that is reflective of the community's cultural horizon. That horizon can be defined by a number of factors, including:

  • the level of personal behavior engaged in health promotion (individual, family, and community/public);

  • the level of interaction and cooperation with local health authorities in matters of personal and public health.

THE CULTURAL HEALTH HORIZON AND THE DEVELOPMENT OF THE LOCAL HEALTH SYSTEM

Responsibility for health is transferred to individual households through the empowerment of individuals to act in ways consonant with that responsibility. Assumptions underlying this transition are:

  • People will act responsibly on their own behalf given sufficient information, resources, and interest, and in the context of a particular cultural horizon that sanctions this behavior;

  • Information can consist of information and resources, but interest must be stimulated from within the community. Information presentation in and of itself does not guarantee the “success” of community-based programs;

  • Health professionals need to determine what the focus of prevention activities should be;

  • The potential threat of a hazardous substance must be made visible to the community so that it may be communicated in ways that can be understood by community members. In transmitting this information, it is imperative to impart knowledge on specific steps that can and should be taken by community members to reduce their exposure, and that of their families, to the hazardous substance in question. Allowances should be made for community-driven modifications in these steps deriving from the culture or other values of the inhabitants.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

Underlying these four assumptions is the recognition that in the past, the community has often been the missing link in addressing environmental and occupational health problems at the local level. The community has often been excluded because members were not considered knowledgeable enough to participate in problem solving. While this paternalistic belief continues to be held by many traditional health professionals, particularly in less-developed countries or in inner-city or rural regions of the more developed countries of the Americas, there is a growing movement toward including community members and other “stakeholders” in the development and implementation of prevention and control programs. Growing experience indicates that such individuals can be vital to the development of innovative and sustainable solutions. Thus, community empowerment should remain a cornerstone of prevention and control efforts.

ALIGNING HEALTH AUTHORITY INTERESTS WITH THOSE OF A COMMUNITY

The best community interventions expand the cultural health horizon of a community by adding culturally relevant alternatives to standard or “textbook” approaches to prevention. In order to do this, the goals and methods of agencies must be aligned with the goals and methods of the community; in other words, they must be made relevant to the community members and vice-versa. How can this be done?

The first step is to appraise the “health horizon" of the community—for example, by determining, in the case of lead, the level of personal behavior directed toward reducing industrial and family exposures. The current degree of information exchanged about the sources and nature of lead poisoning in the community and the interaction between the public health authorities and community members on health issues important to the community also need to be assessed.

As a general rule, we have observed that where the health authorities have a strong bureaucracy, community leadership is suppressed, and health professionals manage the public's health; conversely, where the public health bureaucracy is weak, alternative forms of representation naturally arise. For example, in underserved areas, health authorities are often helped by local grassroots organizations and other NGOs. As a consequence, some of the most innovative experimentation in community education and empowerment is occurring in the most economically disadvantaged populations or in rural areas. This experimentation should be carefully studied to determine the circumstances that foster increased

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

community autonomy and decisionmaking power that translates into improved community health and well-being.

ORGANIZATIONAL MODELS: HEALTH COMMITTEES AND NGOs

To what extent can interested volunteers support and sustain the health of their communities in the face of an increasingly toxic environment? As a first step, there have to be sufficient health personnel, laboratories, and budget to respond to the threat of exposure to hazardous substances. Mexico provides an example where the direct participation of citizens is a real resource. In the small rural towns of Sonora, for example, there are voluntary groups called health committees. These health committees, which are organized by local health authorities but include community membership, have general oversight in matters pertaining to the running of the local health centers and their prevention programs. The committees, in general, have significant political clout with the regional health administrators; thus they can often exert sufficient pressure to obtain needed personnel and services.

In many of the northern border cities of Mexico, NGOs also depend heavily on community volunteers. Although few are currently addressing the issue of lead poisoning in the region, NGOs provide a potentially useful mechanism for dealing with environmental hazards in a manner that can be useful to communities. the NGOs are often staffed by volunteers who act on behalf of their own and their neighbors' best interests. The question then becomes one of how to motivate community members to participate.

COGNITIVE MODELS: POPULAR BELIEFS ABOUT LEAD

Lead toxicity is a major problem in Mexico, as it is in every other country of the Americas. Whole neighborhoods in Tijuana, for example, are exposed to lead poisoning, and this has resulted in significantly lower IQ levels in grade school children living near the lead emission point sources (Guzmán, 1994). Of the children surveyed by Guzmán, 80 percent had blood lead levels that have been associated in cognitive studies with a seven-point performance IQ deficit, and the average blood lead of residents is higher than that associated with severe symptoms of lead poisoning.

To date there has been no consistent public health response to the crisis of lead poisoning in Tijuana, nor has any effective community action been undertaken, in a large part because of a lack of community awareness about the hazards. For many in Tijuana, lead is invisible; for others, who may be aware of the hazards of lead, there is little knowledge about common routes

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×

of exposure, for example, lead-glazed ceramicware or local remedies for such maladies as stomach disorders that contain lead (Baer et al., 1989).

Our study of community perceptions of lead as a health risk in Tijuana produced seven distinct and contrasting perspectives (see Box 3-1). These seven views demonstrate increasing knowledge of the dangers, and the nature and sources of community lead exposure.

BOX 3-1

Seven Stages of Community Perceptions of Lead as a Health Risk, Tijuana, Mexico

Stage 1. Belief: Lead does not exist.

This stage was characteristic of community residents who had never experienced lead poisoning or been associated with someone who had.

Stage 2. Belief: Lead exists as a metal; it has weight, texture, dimension and color. Familiar objects are made from lead.

This stage was characteristic of persons living in marginal communities whose personal life experience includes the recognized use of lead objects.

Stage 3. Belief: Lead exists both in its usual metallic forms and as an intangible substance in air, water, gasoline, soil, ceramics, paints, solder, or other entities.

This stage was characteristic of a few of the more educated residents and of all high school students.

Stage 4. Belief: Lead as a health hazard is recognized at higher levels of intoxication (80+ µg/dl).

This level of knowledge was found among highly educated individuals, and uneducated individuals who have personally experienced the effects of lead-containing industrial waste.

Stages 5 and 6. Belief: Lead as a toxic metal and its sequelae understood.

This level reflects the knowledge of health providers and scientists in the community.

Stage 7. Belief: Lead is a ubiquitous health problem.

This level of knowledge was found among residents who articulated an understanding of the need to regulate lead and of the politics and complexities involved in doing so.

Adapted from Becker, 1974.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
AN ACTION PLAN FOR INCREASING COMMUNITY COMPETENCE ABOUT LEAD HEALTH HAZARDS

The preferred approach to developing strategies to reduce lead exposures is one that utilizes and is based on the capacities, skills, and assets of community members. Much of past public health experience demonstrates that significant advances in community health take place only when local community mentors are committed to investing themselves and their resources in the effort. Depending on its size and sophistication, a given community may have local institutions (such as businesses, schools, parks, libraries, hospitals, and colleges), citizens' associations (including churches, block clubs, and cultural groups), and gifted individuals (for example, artists, retired people, and young people) whose skills and knowledge can be used in the development of effective education and intervention.

Specific steps for accomplishing these ends include:

  • Discovering the existence of active and trusted organizations or other resources within a community. These may include formal organizations (churches, government offices, and the like); informal organizations and networks (such as family and friends); or capacities and assets of individuals, citizens' associations, and local institutions;

  • Undertaking a community-led needs assessment that will allow residents to identify problems and priorities that are most important to them; this step should involve the building of productive relationships among local and state health networks who share the common goal of preventing lead poisoning; and

  • Identifying resource needs and the mechanisms to meet them.

Suggested Citation:"Session D: Case Studies of Interventions." Institute of Medicine. 1996. Lead in the Americas: A Call for Action. Washington, DC: The National Academies Press. doi: 10.17226/9168.
×
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