TIME: Almanac 1993/TIME Almanac 1993.iso/time/022591/0225130.000

Text File | 1992-08-28 | 9.4 KB | 201 lines

                                                                                HEALTH, Page 68

Controlling a Childhood Menace


Lead poisoning poses the biggest environmental threat to the
young

By LEON JAROFF -- Reported by Ann Blackman/Pittsburgh and Janice
M. Horowitz/New York


    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.