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Lead Poisoning: The Ignored Scandal

Spencer Platt/Getty Images
A child with high levels of lead in her blood walking past a wall of peeling lead paint in her family’s apartment, Brooklyn, July 2003


In December 1993, a slum landlord in Baltimore named Lawrence Polakoff rented an apartment to a twenty-one-year-old single mother and her three-year-old son, Max.1 A few days after they moved in, Max’s mother was invited to participate in a research study comparing how well different home renovation methods protected children from lead poisoning, which is still a major problem endangering the health of millions of American children, many of them poor.

Congress had banned the sale of interior lead paint in 1978, but it remained on the walls of millions of homes nationwide, and there was no adequate federal program to deal with it. In Baltimore, most slum housing contained at least some lead paint, and nearly half of the children who lived in these houses had levels of lead in their blood well above that considered safe by the Centers for Disease Control. Max’s blood lead was low when he moved into Polakoff’s apartment, but Polakoff had been cited at least ten times in the past for violating Baltimore’s lead paint regulations, and several former tenants would later sue him for poisoning their children, so the boy was now in great danger.

The research study in which Max and his mother participated was run by two scientists affiliated with Baltimore’s Johns Hopkins University with support from the US Environmental Protection Agency. The scientists had formed a partnership with a local contractor, who identified slum landlords like Polakoff and urged them to rent preferentially to families with children aged six months to four years, just when they start crawling around the house and when lead exposure is most dangerous to the developing brain. If the parents agreed, their home would receive one of three different types of lead removal and their children—all of whom were healthy and normal and had low blood lead when they joined the study—would be given regular blood tests to see if their lead levels rose or fell.2

The three lead removal methods varied in cost and thoroughness. In twenty-five of the homes, areas with peeling paint were scraped and repainted and a doormat was placed by the main entrance. This was called “level I abatement” and the cost was not to exceed $1,650. Another twenty-five homes received more extensive “level II abatement” in which chipping paint was scraped and repaired, doormats were placed at all entrances, an easy-to-clean floor covering was installed, and collapsing walls were covered with plasterboard. The cost of this was not to exceed $3,500. In a third set of twenty-five dwellings, all of the above was done, but in addition, all windows were replaced. The cost of this “level III abatement” was not to exceed $7,000. Two control groups of twenty-five families each were also recruited into the study. Half lived in houses that had been built after the interior lead paint ban in 1978, and half lived in older houses that were supposed to have been fully renovated in the past.

Max’s apartment received level II abatement. While carrying out the work, the contractor noticed some “hot spots”—areas of lead paint that could shed dangerous dust. He pointed them out to Polakoff, and also recorded their location on forms that were sent to the researchers, but no one told Max’s mother. Because of the cost limits for level II abatement, the hot spots were not repaired. When Max was tested six months later, his blood lead had nearly quadrupled, to a level known to cause permanent brain damage.

In 1990, Leslie Hanes, another young black single woman, moved into an apartment that was supposed to have been fully stripped of lead paint years earlier. In 1992, she gave birth to a daughter, Denisa, and in the spring of the following year, she too joined the toddler lead study.3 The day before Hanes signed the consent form, the contractor found that her apartment was not in fact lead-free. The remaining lead paint was removed, but by the following September Denisa’s blood lead level had more than tripled and was now six times higher than that currently considered safe by the Centers for Disease Control.

Denisa’s mother was not informed of the blood test result for another three months, by which time it was nearly Christmas. The research assistant who told her about it wished her happy holidays and advised her to wash her front steps more carefully and to keep eighteen-month-old Denisa from putting her hands in her mouth. When Denisa eventually entered school, she had trouble keeping up and had to repeat second grade. This came as a surprise to her mother, a former high school honors student. As Hanes told The Washington Post’s Manuel Roig-Franzia in 2001, sometimes Denisa came home crying because she thought she was stupid. “No, baby, you’re not stupid,” Leslie told her. “We just have to work harder.”

The link between lead poisoning and low IQ is based on the findings of epidemiological studies of large groups of children, so there’s no way of knowing for certain whether Denisa’s problems—or those of any particular child—were caused by lead poisoning. Some children have a low IQ because they were born that way or for some other reason, but because Denisa’s blood lead level was so high, it’s very likely that in her case, lead poisoning was the cause.

Why was such an unethical experiment ever allowed to proceed? In Lead Wars CUNY’s Gerald Markowitz and Columbia University’s David Rosner convincingly show that the Baltimore toddler study emerged from a century of policymaking in which the US government, faced at various times with a choice between protecting children from lead poisoning and protecting the businesses that produced and marketed lead paint, almost invariably chose the latter. In the process, some of the scientific research on lead poisoning became corrupted.

Long before the Baltimore toddler study was even conceived, millions of children had their growth and intelligence stunted by lead-contaminated consumer products—and some five million preschool children are still at risk today. One expert even estimated that America’s failure to address the lead paint problem early on may well have cost the American population, on average, five IQ points—enough to double the number of retarded children and halve the number of gifted children in the country. Not only would our nation have been more intelligent had its leaders banned lead paint early on, it might have been safer too, since lead is known to cause impulsivity and aggression. Blood lead levels in adolescent criminals tend to be several times higher than those of noncriminal adolescents, and there is a strong geographical correlation between crime rates and lead exposure in US cities.4

In 2000, the two mothers sued the Johns Hopkins–affiliated Kennedy Krieger Institute, which employed the scientists. The mothers’ cases were thrown out by a lower court, but after an appeals court remanded the case to be heard, the mothers reached an undisclosed settlement with the institute. The ninety-six-page appeals court judgment compared the Baltimore lead study to the notorious Tuskegee experiment, in which hundreds of black men with syphilis were denied treatment with penicillin for decades so that US Public Health Service researchers could study the course of the disease.

In September 2011, twenty-five other parents involved in the toddler study filed a class action suit against the Kennedy Krieger Institute, accusing it of negligence, fraud, battery, and violating Maryland’s consumer protection act. Because the children’s medical records are confidential, only their parents and the researchers know for certain which—if any—of them had been poisoned, but all of the plaintiffs claim their children had been endangered. A decision has yet to be handed down.

Surprisingly, many public health experts and professional ethicists defended the Baltimore toddler lead study. Like all US medical research, it had been reviewed in advance by an ethics committee, in this case one based at Johns Hopkins. According to Markowitz and Rosner, the committee’s report questioned only whether the control group children, who lived in supposedly lead-free housing, would receive any benefit from the study, but said nothing about the potential harm to the children in the experimental groups. In a series of medical journal commentaries following the appeals court decision, many public health experts and professional bioethicists claimed that the decision was a disaster for their profession. The president of Johns Hopkins even predicted (incorrectly) that it would drive millions of dollars of research funding from the state. Others argued that research like the toddler study was necessary if affordable solutions to the problems of the poor were to be found.5

Of course researchers should try to find lower-cost solutions to serious public health problems like lead poisoning. However, three aspects of this experiment seem particularly outrageous. First, the landlords recruited into the study were encouraged to rent preferentially to families with small children, but didn’t inform the parents in advance that they were being considered for a research experiment or that they might be better off looking for lead-free housing. Second, the parents were not informed immediately when lead “hot spots” were found in the apartments, or when their children’s lead levels rose. If they had been, they might have taken steps to repair their houses on their own, or even moved out—a nuisance for the researchers, perhaps, but potentially of life-altering benefit to the children.

The third and most important point is that the researchers almost certainly knew in advance that level I and level II abatement—the cheaper of the three methods used—would not protect children from being poisoned. Markowitz and Rosner don’t make this clear in Lead Wars, and so many readers might not realize just how problematic the toddler study really was.6 In the decade before the study commenced, the scientists conducted two other studies in which the homes of children with relatively high lead levels received treatments very similar to level I and level II abatement. Some of these homes also received bimonthly visits from a professional “dust control team”—something not offered to the families in the toddler study. After one year, lead levels in some of the children in these earlier studies had risen so high they had to be hospitalized.7 The most likely reason was that these cheaper abatement methods didn’t involve the replacement of lead-paint-trimmed windows, which can produce plumes of lead dust every time they are opened or closed.8

As one of the scientists wrote in a 1984 letter to The New England Journal of Medicine, such partial methods should not be used for protecting the general population: “more permanent changes,…such as replacement of a deteriorated window casement, may be a more effective long-term solution.”9 In subsequent studies, the scientists showed that window replacement was indeed crucial for the reduction of lead dust in contaminated houses,10 and that the amount of lead dust remaining in the toddler study homes after level I and level II abatement was similar to, and in some cases higher than, that found in scores of homes in which children had been poisoned in the 1980s.11 Why did the scientists then proceed to test two ineffective lead abatement methods on healthy children?

The researchers themselves seem to have been decent men. The senior researcher, J. Julian Chisolm, conducted a door-to-door survey of Baltimore slum children in the 1950s and found that on average, their lead levels were six times higher than among workers employed in the lead industry itself. He then helped develop a treatment known as chelation, in which lead-poisoned children are given injections of chemicals that bind to lead and draw it out of the tissues so that it can be excreted. The injections are painful, must be administered over several weeks, and don’t prevent brain damage, but they do prevent death.

Mark Farfel, Chisolm’s younger colleague, told The Baltimore Sun that it had always bothered him that children who were already sick received state-of-the-art hospital treatment, but so little was being done to prevent them from being poisoned in the first place. Farfel refused to speak to Markowitz and Rosner, and Chisolm was no longer alive when they began writing their book. But from the history they relate in Lead Wars, it’s possible to imagine how these men could not effectively resist the momentum of government indifference to the poor, pervasive racial prejudice, and careless decision-making that influenced government policymaking throughout the lead-poisoning crisis.

A coloring book from the 1920s extolling the virtues of lead paint. According to Gerald Markowitz and David Rosner in Lead Wars, lead paint ‘was aggressively marketed as the covering of choice to millions of young families through jingles, advertisements, and even paint books for children, who were told, for example, “This famous Dutch Boy Lead of mine can make this playroom fairly shine.”’

The Lead Menace April 4, 2013

  1. 1

    The child’s name has been changed. 

  2. 2

    Some families were recruited in situ; in these cases, the apartments they were already living in were subjected to either type 1 or type 2 abatement. 

  3. 3

    The mother’s and daughter’s names have been changed. 

  4. 4

    See Shankar Vedantam, “Research Links Lead Exposure, Criminal Activity,” The Washington Post, July 8, 2007. 

  5. 5

    See, for example, Robert M. Nelson, “Nontherapeutic Research, Minimal Risk, and the Kennedy Krieger Lead Abatement Study,” IRB: Ethics and Human Research, Vol. 23, No. 6 (November–December 2001); Anna C. Mastroianni and Jeffrey P. Kahn, “Risk and Responsibility: Ethics, Grimes v Kennedy Krieger, and Public Health Research Involving Children,” American Journal of Public Health, Vol. 92, No. 7 (July 2002); B.P. Lanphear, “Editorial: The Conquest of Lead Poisoning: A Pyrrhic Victory,” Environmental Health Perspectives, Vol. 115, No. 10 (October 2007). 

  6. 6

    In their grant proposal for the toddler study, the researchers claimed that they intended to test “a new approach” to lead abatement, a statement quoted uncritically in Lead Wars. In fact, many of the children in the study were being placed in homes treated with methods that had been shown to fail. 

  7. 7

    J.J. Chisolm Jr., E.D. Mellits, and S.A. Quaskey, “The Relationship Between the Level of Lead Absorption in Children and the Age, Type, and Condition of Housing,” Environmental Research, Vol. 38, No. 1 (October 1985), pp. 31–45; E. Charney, B. Kessler, M. Farfel, and D. Jackson, “Childhood Lead Poisoning: A Controlled Trial of the Effect of Dust-Control Measures on Blood Lead Levels,” The New England Journal of Medicine, Vol. 309, No. 18 (November 3, 1983), pp. 1089–1093. 

  8. 8

    M.R. Farfel, J.J. Chisolm Jr., and C.A. Rohde, “The Longer-Term Effectiveness of Residential Lead Paint Abatement,” Environmental Research, Vol. 66, No. 2 (August 1994), pp. 217–221; M.R. Farfel and J.J. Chisolm Jr., “Health and Environmental Outcomes of Traditional and Modified Practices for Abatement of Residential Lead-Based Paint,” American Journal of Public Health, Vol. 80, No. 10 (October 1990), pp. 1240–1245. 

  9. 9

    Evan Charney et al., “Effect of Dust Control on Blood Lead,” The New England Journal of Medicine, Vol. 310, No. 14 (April 5, 1984), pp. 924–925. 

  10. 10

    Farfel et al., “The Longer-Term Effectiveness of Residential Lead Paint Abatement.” 

  11. 11

    Compare Table ES-2 in “Lead-Based Paint Abatement and Repair and Maintenance Study in Baltimore: Findings Based on Two Years of Follow-Up” (Environmental Protection Agency, 747-R-97-005 December 1997), to Table 4 in Mark R. Farfel and J. Julian Chisolm Jr., “An Evaluation of Experimental Practices for Abatement of Residential Lead-Based Paint: Report on a Pilot Project,” Environmental Research, Vol. 55, No. 2 (1991), pp. 199–212. It is necessary to convert micrograms per square foot into milligrams per square meter. 

  12. 12

    See Helen Epstein, “ Getting Away with Murder,” The New York Review, July 19, 2007.  

  13. 13

    University of Minnesota Press, 2011. 

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