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Getting the lead out.

from brain damage.

Lead poisoning is, in the words of the U.S. Centers for Disease Control, the "most common and societally devastating environmental disease of young children." Millions of American children are exposed to enough lead to lower IQ, impair memory, and reduce the ability to learn. Although there are many environmental sources of lead, including soil and dust contaminated by leaded gasoline, drinking water contaminated by lead plumbing, and lead-containing glazes on dishware, the most prevalent source of high-intensity exposures is deteriorating lead-based paint, which was widely used before being restricted in the 1970s. As paint becomes worn or is disturbed during renovations, it releases lead particles into household dust, which is ingested by children during their normal hand-to-mouth activities.

Today, deteriorating lead-based paint is found most often--though by no means exclusively--in privately owned, low-income housing. According to the U.S. Department of Housing and Urban Development (HUD), almost 75 percent of U.S. homes built before 1980 contain some lead-based paint. Much of that paint is in good shape and poses no current hazard. But approximately 2 million homes are occupied by lower-income families with children and contain what HUD terms "priority" lead hazards: nonintact lead-based paint or high-lead dust. Just over one-third of these homes are owner-occupied; the remainder are rental units. Millions of additional low-income units rate as priority hazards but do not currently house children. They pose a threat to children who may reside there in the future.

The crisis in affordable housing compounds the difficulty of preventing lead-paint exposure. Landlords generally will not spend money to abate hazards unless they can pass the costs through to tenants, but low-income families typically cannot afford those rent increases. Nor can they afford the specialized training and materials needed to safely abate severe hazards themselves. And alternative housing is scarce and also likely to present lead hazards.

No meaningful response to this problem has yet been adopted at any level of government or in the private sector. As a result, there is an acute shortage of funding for abating priority hazards in low-income housing--the very hazards that cause the most damaging exposures. The consequences for children are profound.

A program to abate severe hazards in low-income housing would cost more than $10 billion, but the cost to society of failing to take action will be even greater. Congress is in no mood for expensive new programs, so alternatives to direct appropriations must be identified. Action is urgently needed, and some creative policymaking could make available adequate resources to prevent the tremendous social harms induced by lead exposure among young children.

Why worry about lead?

Because lead is an element, it does not decay. Thus, it does not lose its toxicity over time. In the human body, its half-life is measured not in weeks, months, or even years, but in decades. In the environment, its half-life is infinite. Once lead is disinterred from natural ores, it can be shifted from here to there, presenting a threat of greater or lesser immediacy at one location or another--but it does not stop being lead. For thousands of years, humans have dug up this metal and used it in ways that have contaminated the biosphere. But during most of our history as a species, humans have been exposed to only the small amounts of lead that entered the biosphere through weathering of the earth's crust and similar forces. The level of lead in human blood in preindustrial times has been estimated at around 0.016 millionths of a gram per deciliter (0.016 [mu]g/dL).

Today, however, average blood-lead levels in the United States are at least several hundred times higher. These are the legacy of decades of dispersive use of lead in paint, gasoline, plumbing pipes, and other products. Although blood-lead levels have declined roughly threefold over the past two decades, in the wake of restrictions on the use of lead in gasoline, paint, and food-can solder, the current average level among children is estimated to be about 5 [mu]g/dL--300 times greater than in preindustrial humans.

The fact that current exposures greatly exceed natural ones does not by itself indicate that higher levels are harmful. But a wealth of evidence supports the conclusion that they are. Lead exposure in adults causes a variety of adverse effects, ranging from slight increases in blood pressure at low exposures to reproductive impairment and neurological damage at higher doses. Lead's effects on children, however, are generally regarded as its most significant public health consequences.

At levels beginning in the range of 6-15 [mu]g/dL, lead impairs neurocognitive function in young children, measured in terms of decreased IQ, impaired short-term memory, slowed reaction time, and reduced ability to concentrate. One recent study, directed by Peter A. Baghurst, of middle- and upperclass Australian children found that the average IQ of children with blood-lead levels of 30 [mu]g/dL was 5 points lower than that of children with blood-lead levels of 10 [mu]g/dL. After adjustment for covariates--factors such as family income and maternal IQ--the gap was found to be 7.8 points for girls and 2.6 points for boys. Another recent study led by David C. Bellinger observed children whose blood-lead levels at 24 months were between 0 and 25 [mu]g/dL. By the time the children were 10 years old, an initial 10 [mu]g/dL differential in blood-lead levels at 24 months was associated with a 5.8 point gap in average IQ scores, adjusted for confounders. The children in this study were generally white, relatively high-functioning offspring of intact families with college-educated parents.

A pioneering set of studies directed by Herbert L. Needleman and colleagues beginning in the late 1970s demonstrates the long-term implications of childhood lead exposure. Because blood-lead values indicate exposures occurring only within the previous month or so, the researchers ranked children's lead exposure based on their dentine (tooth) levels, which reflect longer-term exposure patterns. Following these children through high school, these investigators found that, compared with children with the lowest dentine-lead levels, children with the highest tooth-lead levels were seven times more likely to drop out of school, were six times more likely to suffer from reading disabilities (defined as reading two or more grades below the expected level), and achieved lower final class standing in high school, after adjustment for covariates. It is difficult to compare these data with those using blood-lead levels to assess exposure. Although none of these children were diagnosed as lead-poisoned, both the high- and low-lead groups had relatively high blood-lead levels by current standards, and compared with the Baghurst and Bellinger cohorts. In a limited blood-sampling program, the high-lead group had a mean blood level of 34 [mu]g/dL, and the low-lead group 24 [mu]g/dL.

These elevated rates of academic failure reflect not only lead's effect on IQ but also its neurobehavioral effects. During earlier assessments, high-lead children had been ranked by their teachers (who did not know the children's lead status) as more irritable, easily distracted, and aggressive. Similar results have been obtained in several additional prospective and cross-sectional studies in the United States, Australia, Denmark, Germany, and Greece, though a few other researchers have not observed lead-related performance effects.

Irritability, distractability, and aggressiveness--these characteristics impair a child's academic performance and can cause him or her to disrupt an entire classroom, absorbing vastly disproportionate amounts of a teacher's time and attention. In this way, lead poisoning can harm not only the afflicted child but also his or her classmates. Lead poisoning may well be an important contributing factor in the devastatingly high rates of school failure in poor, urban communities, where lead exposures are endemic.

Lead's potency is compounded by its persistence in the human body. Even minute exposures to lead accumulate in the body, producing effects that may endure long after the exposure ends. Once absorbed, lead is stored primarily in bone and, to a lesser degree, in the kidneys and the brain. Only a small portion circulates in the blood at one time.

The mobilization of lead from bone into the blood during pregnancy is of particular concern. Women who have borne children appear to have lower skeletal lead levels than those who have not, indicating that lead may have been transferred to the children during gestation and/or nursing. Mobilization of lead from bone can acutely intoxicate pregnant women who have high bone-lead stores. Moreover, the fetus is highly susceptible to the nuerotoxic effects of lead, which moves freely across the placenta. In rare cases, babies can be born with clinical signs of lead poisoning. Inadequate calcium in the mother's diet during pregnancy and lactation may accelarate the mobilization of lead, providing another instance of the disproportionate impact of lead poisoning on the poor.

When to worry

In October 1991, the U.S. Centers for Disease Control (CDC) released new guidelines on preventing childhood lead poisoning. The 1991 guidelines depart from the CDC's prior practice of identifying a blood-level of 25 [mu]g/dL as "lead poisoning," a standard established just six years earlier. Instead, they adopt a multitiered approach and establish a blood-lead level of 10 [mu]g/dL as what has become known as a "level of concern." The guidelines note that "the scientific evidence showing that some adverse effects occur at blood-lead levels at least as low as 10 [mu]g/dL in children has been so overwhelming and compelling that it must be a major force in determining how we approach childhood lead exposure." The Environmental Protection Agency (EPA) estimates that, in 1990, 15 percent of children under age 6 (roughly 3 million preschoolers) had blood-lead levels exceeding this standard.

Reflecting the scarcity of resources for addressing lead exposures, as well as the limits of available treatments, the guidelines recommend "simple interventions" for children whose blood-lead levels are slightly above the level of concern: cleaning the home to reduce exposure to dust and soil, and attention to nutrition (since dietary deficiencies in iron and calcium promote lead absorption from the stomach). For blood-lead levels above 20 [mu]g/dL, the CDC recommends full medical evaluations and environmental interventions to reduce lead exposures. EPA estimates that about 1 percent of U.S. children under age 6 (more than 200,000) have blood-lead levels exceeding even the older standard of 25 [mu]g/dL. In 1993, the Academy of Pediatrics issued a policy statement on lead poisoning prevention that essentially parallels the CDC recommendations.

The social costs of high-intensity lead poisoning are immense. In its February 1991 "Strategic Plan to Eliminate Childhood Lead Poisoning," the CDC calculates that the present (time-discounted) benefit of preventing one child's lead level from rising above 24 [mu]g/dL is $1,300 in avoided medical costs and $3,331 in avoided special education costs. In addition, every 1 [mu]g/dL increase in blood-lead level--regardless of starting blood-lead level--decreases lifetime earnings by $1,147 because of lowered IQ.

These figures do not reflect numerous other benefits of reducing lead exposure. Perhaps most strikingly, the CDC's analysis disregards any contribution of lead-induced neurobehavioral dysfunction to juvenile delinquency caused by a child's inability to concentrate and succeed in school. As the CDC acknowledges, "By not including these effects, we grossly underestimate the costs of lead exposure to society."

Even using these conservative estimates, the overall costs of lead poisoning are remarkable. Allowing a single child to develop a chronic blood-lead level of 25 [mu]g/dL costs more than $4,600 in medical and educational expenses, and more than $28,000 in lost income. Children exposed to deteriorating paint can develop considerably higher levels. And a single deteriorating home can--and too often does--poison child after child after child. Multiply the figures above by the 2-million-plus homes throughout the United States with severely deteriorating paint and the social costs over time run well into the billions.

The need for federal intervention

To date, the United States has failed to craft effective programs for preventing lead poisoning. Such programs require identification and control of sources before exposure occurs. Prevention of high-intensity lead exposures is fully within our power: We know what the sources are, we know where they are, and we know what factors (age and condition of housing) increase the risk of exposure to those sources. Yet, virtually all existing programs take action only after a child is poisoned, and focus on the linkage between a particular child and his or her residence. If the poisoned child moves, the new residence typically is not checked, nor is the old one abated.

Recognizing the ineffectiveness of this approach, the Centers for Disease Control called for increased abatement of leaded paint and lead-contaminated dust as a key element of its landmark "Strategic Plan for Elimination of Childhood Lead Poisoning." As the CDC observed, "Until this environmental source of lead is eliminated, the United States will continue to have a significant childhood lead poisoning problem." Likewise, the American Academy of Pediatrics' 1993 policy statement recognizes the importance of source control in lead poisoning prevention.

During a demonstration project, HUD found that the average cost of abating priority-hazard units ran from $8,870 to $11,870. The lower figure was for abatement using an encapsulation approach (covering up the paint with a durable surface) and the higher figure was for a removal strategy (stripping the paint on-site or off-site, or replacing the lead-painted component). Unfortunately, simply painting over a deteriorated surface is an exercise in futility, since an unstable surface typically will begin to peel again within weeks. Although "good housekeeping" measures such as routine mopping can help reduce exposures to a modest degree, preliminary studies in Baltimore indicate that such measures alone do not adequately control lead-dust levels where severe hazards exist.

Nor can untrained persons undertake abatements safely. Improper abatements generate large quantities of lead dust or fumes, particularly if painted surfaces are sanded or if heat guns are used. Rigorous dust containment and cleanup (including repeated mopping and use of high-efficiency particulate air vacuums) are also essential. Even when parents take precautions such as sealing off the work area and doing daily washups, children's blood-lead levels are likely to rise, sometimes dramatically. Indeed, the Consumer Product Safety Commission flatly warns that consumers should not attempt to remove lead-based paint.

In short, major abatement projects are far out of reach for low-income families. These families are already strapped trying to meet their budgets for food, clothing, shelter, and other necessities. Although significant efforts to lower abatement costs are now under way--including the formation of a nonprofit National Center for Lead-Safe Housing to help collect and evaluate basic data--even a 50 percent reduction in cost will still leave abatement unaffordable for low-income families.

Landlords in the private sector can seldom absorb the costs of abating hazards in low-income (and thus low-rent) housing either. Experience in Baltimore has shown that if landlords are required to pay the full cost of hazard abatement, they threaten to abandon the low-income housing market. This does the tenants no good: Lead poisoning is bad, but homelessness is hardly preferable.

Little help is available from state and local lead-poisoning prevention programs. As noted in a recent report by the U.S. General Accounting Office (GAO), "Even the most aggressive state lead-poisoning prevention programs are limited by scarce financial resources at the state and local levels."

GAO's conclusion is confirmed by a recent report issued by the Environmental Defense Fund on selected state and local programs. That survey reveals that abatement needs are nowhere close to being met, even in cases where lead poisoning has already occurred. In Baltimore, for example, there is a backlog of hundreds of houses in which children have been moderately or severely poisoned (i.e., have developed blood-lead levels above 20 [mu]g/dL). Indeed, officials interviewed during the survey repeatedly stressed that abatement assistance is the area in which additional funding is most desperately needed. As one state health officer remarked, "What's the point of screening [children for lead poisoning] if you're not going to abate?"

Existing federal programs also fall far short of the mark. Only one federal program provides targeted funds for abating lead hazards, a competitive grants program operated by HUD. Its funding for fiscal year 1993 is a mere $90 million. This is a modest drop in a $10-billion bucket of need. While other HUD programs nominally allow for testing and (if necessary) abatement, those programs are perennially underfunded and must be stretched to cover a host of competing demands. HUD itself has no data to indicate how much, if any, of this money is in fact used for abatement. In any event, the programs have thus far failed to remedy even severe hazards.

A levy on lead

Cost-benefit analysis clearly supports the wisdom of investing national resources in the prevention of high-intensity lead exposures from deteriorating paint. But, a deficit-plagued Congress is unlikely to commit significant new funding to this project. Responding to the urgent need for dedicated abatement funding, we propose a "polluter pays" approach: Tax lead as it enters U.S. commerce and place the proceeds in a trust fund for use by states and localities in abating priority hazards. Legislation to this effect was introduced as H.R. 2922 in the 102nd Congress, and its principal sponsor (Rep. Benjamin Cardin, D-Md.) plans to reintroduce it in the 103rd Congress.

The 1993 version of the legislation calls for a 10-year tax of approximately 45 cents per pound on domestic and imported lead, including lead in products above a deminimus level (0.06 percent). Though the tax would approximately double the price of lead, lead would remain one of the least expensive metals. About 80 percent of lead now used in U.S. commerce goes into large rechargeable batteries for cars, other vehicles, and industrial applications. The impact of the tax will vary by product, depending on substitutes and other factors. For instance, assuming that the tax is entirely passed through to the consumer, it would show up as approximately an $8 increase in the price of a standard car battery, which contains about 18 pounds of lead.

Once lead is taxed, its higher price would also provide an incentive to maximize the recovery rate for lead from discarded consumer products (such as lead batteries). Although battery recycling rates are reported to exceed 90 percent at present, the large amount of lead in each battery means that up to 150,000 metric tons of lead escape recycling. Thus, the tax would help cut down on contamination of the environment from the unnecessary disposal of lead products.

In 1992, total U.S. lead consumption was 1.22 million metric tons. Thus, the tax will raise roughly $1 billion per year to operate comprehensive state and local programs addressing deteriorating lead-based paint in low-income housing and day-care centers. Funds will be allocated on the basis of a statutory formula reflecting local needs related to poverty and the prevalence of lead-paint hazards. To receive annual grants under the formula, cities and states must match a portion of the federal grant and demonstrate their capacity to carry out the program efficiently and effectively by submitting "approvable plans" to HUD.

The legislation targets private housing occupied by low-income families, including rental as well as owner-occupied properties. The program will also help cover the costs of abating hazards in day-care centers.

Why pay for abatements by taxing lead? The answer is simple: The cost of abating priority hazards in order to prevent lead poisoning is most fairly borne by the industry that profited from lead in the first place. The tax will internalize externalities, albeit imperfectly across the intervening decades. And it will place on the lead industry responsibility for some of its past actions.

For decades after the health hazards of lead-based paint were identified, the lead industry continued to promote its use. Indeed, lead paint was first identified as a source of childhood lead poisoning in 1904. By 1921, an international treaty--which the United States did not adopt--limited the lead content of most pigments to 2 percent.

Relying on appropriations from general revenues is untenable for two reasons. First, the likelihood of securing adequate appropriations is, at best, remote in the current fiscal climate. Under the terms of the 1990 budget agreement, appropriations subcommittees have limited--and inadequate--amounts of money to allocate. The president's FY 1994 budget seeks level funding, at $90 million, for HUD's competitive grants program. Without a substantial new source of revenue, spending $1 billion on abatement each year for a decade would require equivalent cuts that would be likely to hit other health, housing, or environmental programs--robbing Peter to pay Paul.

Second, annual appropriations are difficult to predict. The creation of a 10-year dedicated revenue stream will allow public health officials and private abatement contractors to develop an abatement infrastructure in an orderly, cost-effective fashion. In turn, this will make rational long-term planning possible. Once abatement workers are trained and specialized equipment is purchased, the per-unit costs of abatement will drop. It makes no sense at that point to scale back abatement programs as annual appropriations fluctuate.

Congress has previously ear-marked funds in order to generate secure, long-term funding directed at long-term policy goals. In the environmental arena, for example, the Hazardous Substances Trust Fund (commonly known as "Superfund"), the Nuclear Waste Fund, and the Leaking Underground Storage Tank Trust Fund each operate to achieve a specific goal similar to that of abating priority lead hazards.

The lead-paint abatement trust fund will have several important ancillary benefits. First, it will create jobs in the nascent abatement industry. Because expenditures under the program are targeted to homes occupied by low-income residents, these jobs will be available in low-income communities and could provide opportunities for training and employment.

Second, by allowing severe hazards to be abated before additional children are poisoned, the bill will reduce the number of future lawsuits that would otherwise be filed seeking compensation for those children's injuries. By avoiding the costs of litigation, the program will enable society's resources to be put to more productive use.

A third ancillary benefit is the creation of economic incentives to find and use substitutes for lead where technically feasible. Overall lead usage in this country has actually increased in the past decade, from 1.11 million metric tons in 1982 to 1.22 million metric tons in 1992. Although many of the most dispersive uses have been curtailed, all uses of lead directly or indirectly contaminate the environment--if not during the lifetime of a product, then during mining, smelting, product manufacture, or product disposal. The best way to prevent lead--or any other toxic substance--from entering the environment is not to dig it up. No subsequent "command-and-control" regulations can contain all of it.

It is important to note that most of the lead smelters now in operation in the United States have repeatedly violated existing environmental and occupational standards. And those standards are regarded by experts as inadequate. For example, the EPA's Clean Air Scientific Advisory Committee recently noted that levels approaching the current standard for ambient air provide "relatively little, if any, margin of safety."

Similarly, occupational lead exposures are unacceptably high throughout major portions of the work force. As a recent editorial in the American Journal of Public Health noted, "Present [occupational] standards are not protective . . . . Workers exposed to lead at levels below the current [standard] are suffering toxicity. . . . The continuing over-exposure of American workers to lead and the persistent occurrence of occupational lead poisoning is a national scandal."

Social alchemy

The trust fund, and the tax that finances it, are part of a broader policy shift in our society's attitude toward lead. Throughout history, lead has been viewed as useful and cheap. Considerably less emphasis has been given to its other characteristics: its toxicity, its persistence, and its propensity to accumulate in the body. This unique and tragic constellation of characteristics creates an ineluctable need for fundamental change--what might be termed a social alchemy of lead. This term connotes not the physical transmutation of lead, but rather a transformation of society's perception of this substance. Instead of using lead wherever there is a need for a material that is heavy, malleable, or cheap, lead should be used only where its chemical and physical properties are uniquely suited to the task at hand (e.g., for radiation shielding), and only when, after that task is completed, the product and its lead can be retrieved in a controlled fashion that does not increase human or environmental exposure. Significantly increasing the price of lead is one mechanism for accomplishing this goal. Other particularly high-exposure or plainly unnecessary uses may also warrant more focused attention, such as restrictions on nonresidential paint, ceramic glazes, and lead curtain weights.

In addition, we must respond to the legacy of our old attitude toward lead by taking urgently needed steps to reduce hazardous exposures that already exist. Taxing the lead industry to fund priority abatements is not a perfect solution. Ideally, we would borrow H.G. Wells' time machine, travel back to the early 20th century, and tax lead as it was produced (or, better still, prohibit use of lead paint in homes in the first place). But that avenue is not open to us. Millions of tons of lead were used in paint decades ago; this lead is poisoning children today. The question is what to do now.

The lead industry thwarted actions 50 to 80 years ago that would have greatly reduced the scope of the problem confronting us today. Now, it is fair to ask the lead industry to contribute to the prevention of severe lead poisoning. The least equitable route--indeed, an indefensible one--is to maintain the status quo, allowing children to be highly exposed to a substance well known to rob them of their intellectual potential.
COPYRIGHT 1993 National Academy of Sciences
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Title Annotation:alternatives for lead-based paints
Author:Florini, Karen L.; Silbergeld, Ellen K.
Publication:Issues in Science and Technology
Date:Jun 22, 1993
Words:4312
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