Controlling A Childhood Menace

By LEON JAROFF

Sitting on an examining table at the Children's Hospital in Pittsburgh, three-year-old Shawntea West is smiling and alert, apparently in excellent health. But she is afflicted with the most common of the serious childhood diseases. The mumps? Viral meningitis? Measles? Whooping cough? The answer, says Dr. Herbert Needleman as he draws blood from her arm, is lead poisoning.

During a routine checkup two weeks earlier, Shawntea was found to have a level of 25 micrograms of lead per deciliter of blood. If that toxic level is maintained, it could affect her mental capabilities and result in grave behavioral and physical problems. "She was living in raggedy housing and eating plaster from a big hole in the wall," says her grandmother, who accompanied her. To Dr. Needleman, that is an important clue; it is likely that some of the earlier coats of paint on the wall contained lead. "Make sure she washes her hands before she eats," he says, "and don't let her eat dirt or plaster."

Shawntea's case is hardly unique. From 3 million to 4 million American children -- or about 1 out of every 6 -- under six years old have lead poisoning. While only 7% of young children from medium- and high-income families are afflicted, it affects 25% of poor white children and an incredible 55% of those from impoverished black families.

These startling statistics are contained in a "strategic plan" developed by the Department of Health and Human Services. Though HHS warns that the effects of exposure to even moderate amounts of lead are more pervasive and long lasting than was previously thought, its plan optimistically outlines a program for eliminating lead poisoning in children within 20 years. Dr. Needleman, a pioneer investigator of the disorder at the University of Pittsburgh medical school, feels that the goal is attainable. "Lead poisoning is the most severe environmental disease in this country," he says, "and it is totally preventable."

But total prevention could be an elusive goal. Americans are constantly exposed to lead, particularly from old, crumbling paint. The dense metal escapes into the air when used in industrial processes and can leach out of crystal glassware and imported pottery into food and drink. Lead solder in old plumbing often contaminates tap water. Government regulations have phased out most leaded gasolines, but the residue from the exhausts of millions of vehicles in years gone by still poisons the soil near major highways. And though lead-based paints were banned for most uses in 1977, a 1988 Public Health Service report revealed that 52%, or 42 million, of the nation's households have layers of lead-based paint on their walls and woodwork.

Even in minute quantities, lead is highly toxic. Some historians suggest that widespread lead poisoning contributed to the decline of ancient Rome, where the metal was used for tableware, weapons, cosmetics and water pipes in aqueducts, as well as in the processing of wine. Its prevalence, some conjecture, may have caused sterility, miscarriages and even insanity, particularly among members of the upper classes, who imbibed heavily.

Ingested or inhaled, lead enters the bloodstream, where it inhibits the production of hemoglobin, which red cells need to carry oxygen. It also locks on to essential enzymes in the brain and nervous system, inactivating them. Symptoms of lead poisoning include abdominal pains, muscular weakness and fatigue; severe exposure can cause nervous-system disorders, high blood pressure and even death.

While adults, especially those in certain occupations and industries, are vulnerable to lead poisoning, small children are at the greatest risk. Dr. Joseph LaDou of the University of California at San Francisco explains that children are "exquisitely sensitive" to the toxic metal because their nervous systems and brains are still developing.

Does an effective treatment for lead poisoning exist? Yes, provided it begins before too much damage is done. Doctors get the lead out with a process called chelation, using drugs that bind to the metal in the bloodstream, allowing it to be flushed out in the urine. The drug of choice has been calcium-disodium EDTA, but it is usually administered intravenously over several days in a hospital. The Food and Drug Administration has approved for + use in children an oral drug called DMSA, which does not require hospitalization. But effective as chelation is, doctors point out that medical treatment cannot substitute for a safe environment. "Prevention is the key," says LaDou. "It's a dream that we can find drugs to protect us from environmental hazards."

The effects of low-level lead poisoning in children are not immediately obvious, but they can have a devastating, permanent impact. Exhaustive tests conducted by Dr. Needleman on 2,300 suburban Boston schoolchildren confirmed that even modest lead exposure lowers IQs, impairs memory and reaction time and affects the ability to concentrate. "This is an information society," says Karen Florini, a Washington attorney with the Environmental Defense Fund. "When your educational and social skills are hurt early on, you aren't likely to become a productive member of society." John Rosen, a professor of pediatrics at the Montefiore Medical Center in New York City, agrees: "The fact that we have a pervasive problem that has the capacity to rob young children of their potential forever is, in 1991, a national disgrace."

By far the highest incidence of lead poisoning is found in children who live in older homes with lead-based paint that is peeling. For many years public health officials assumed that most cases were the result of toddlers' eating the sweet-tasting chips and flakes. More recently, however, researchers have recognized that dust from deteriorating paint, settling onto windowsills, furniture and carpets, poses a more pervasive threat. "It's the teddy bear lying in the corner on lead-laden dust that the children are touching," says Rosen. "Putting fingers in their mouth is normal activity for kids. The lead goes from their toys, their clothes, their furniture into their mouths."

New perceptions about the toxicity of lead have convinced many experts that the currently accepted danger level of 25 micrograms per deciliter of blood is too high. HHS favors lowering the warning level to 10 micrograms. Testing blood levels, however, may be an imperfect index of danger. "Measuring the blood is convenient and often useful," explains Richard Wedeen, a nephrologist at a V.A. hospital in East Orange, N.J., "but it may not be where the lead is." The problem is that only a few months after entering the bloodstream, much of the lead has migrated to the bones, where it can persist for decades without doing damage. But it can re-enter the bloodstream and % cause trouble, especially under stressful conditions -- surgery, infection, emotional upheaval.

Consequently, some doctors analyze a patient's bones or teeth to gauge the extent of lead poisoning more accurately. In young children, baby teeth that have fallen out can be tested for lead content. This procedure is obviously impractical for adults, who can be tested by new, noninvasive X-ray fluorescence techniques. The X rays penetrate tissue and excite lead atoms in the living bone, causing them to emit radiation that reveals lead levels.

Can lead poisoning be eradicated as a threat to children as, say, polio has been? Yes, says the Environmental Defense Fund's Florini. "We don't need to invent new technologies to remove lead. We know how to do it. What's needed is money." Authors of the HHS strategic plan apparently agree. They call for a four-point effort that requires 1) establishment of national surveillance for children with elevated blood levels of lead; 2) elimination of leaded paint and contaminated dust in housing; 3) reduction of children's exposure to lead in water, food, air, soil and places of play; and 4) an increase in community programs for the prevention of childhood lead poisoning.

The plan could cost as much as $10 billion over the next 10 years, but its authors claim that eliminating lead from all pre-1950 housing would alone save $28 billion in medical expenses and other costs. Though the Office of Management and Budget has raised allotments for lead-screening programs from only $4 million in 1990 to a proposed $41 million for 1992, it is balking at further expenditures.

Environmentalists and health officials are determined not to lose a historic opportunity to stop lead poisoning in America. The Romans, notes nephrologist Wedeen, chose to ignore warnings by the architect Vitruvius, who declared that the aqueducts' lead pipes were fit for carrying only sewage, not drinking water. "That is not unlike what is going on today," says Wedeen. "People know about the dangers of lead, but they just don't do very much about it." If the HHS recommendations are adopted, the lessons of history may finally pay off. But that, as the saying goes, is far from a lead-pipe cinch.

With reporting by Ann Blackman/Pittsburgh and Janice M. Horowitz/New York