Getting the lead out … of just about everything – regulating lead exposure, preventing lead poisoning, researching the effects of lead are all responsibilities of government agencies – includes articles on areas of responsibility within the government and how to avoid lead exposure
A Puerto Rican family moved here from the Caribbean with high hopes for a better life. They set up housekeeping in low-income housing in eastern Massachusetts, and four of the six children developed lead poisoning, shattering family dreams.
When questioned, the 10-year-old son answers that he lives in the state of Boston and that George Washington is president of the United States. He cannot count to 30. His younger brother with severe lead poisoning is chronically restless. He is unable to sit still, and the doctor describes him as roaming around the doctor’s office like “a caged animal.”
In another case, the ninth of 10 children of a well-to-do Boston family had seizures and was in a coma as a child as a result of lead poisoning. She ultimately recovered and went to school and then to college. But her history shows she had tremendous emotional difficulties throughout her life and has managed to cope only because her family had the financial resources to help.
Not fictitious children, they represent but a few of the cases that John Graef, M.D., associate clinical professor at Harvard Medical School and chief of the lead and toxicology program at Children’s Hospital in Boston, has encountered in his career. “I think we all get numbed by the numbers,” he says. “These are real people. Statistics do not tell the whole story…. One of the things that worries us is that no matter where we look, there are ways for lead to enter our bodies.”
Despite successful cleanup efforts–such as the reduction in the numbers of lead-soldered food cans, which FDA has urged, and the removal of lead from gasoline–health problems caused by repeated exposure to lead continue to endanger Americans. And children are particularly vulnerable. According to the February 1991 Strategic Plan for the Elimination of Childhood Lead Poisoning, developed for the Department of Health and Human Services, “Lead poisoning remains the most common and societally devastating environmental disease of young children.”
Lead has no known functions or health benefits for humans. It is considered a metabolic poison (meaning it inhibits some of the basic enzyme functions) and has caused humanity untold ills.
“Once lead enters the body, it is treated like calcium because the body can’t tell the difference between the two,” says Joseph LaDou, M.D., chief of the division of occupational and environmental medicine, University of California in San Francisco. After several weeks, lead leaves the bloodstream and is absorbed by bone, where it can continue to accumulate over a lifetime.
Probably the first published link between lead ingestion or inhalation and illness or death was made in the second century B.C. by the Greek physician Nicander, who wrote graphically about the tortures of lead poisoning–foaming lips, bloated belly, drooping limbs, and an inflamed mouth. Without intervention, Nicander observed, “the sick man descends to the Stygian shades.”
Since that time, scientists and physicians have catalogued a lengthy list of health effects that they attribute to lead: damage to the kidneys and liver, and to the nervous, reproductive, cardiovascular, immune, and gastrointestinal systems. In children, as scientists have recognized, lead has a particularly damaging effect on intellectual development. In addition, lead interferes with the manufacture of heme, the oxygen-carrying part of hemoglobin in red blood cells. Extremely high levels of lead in the body cause encephalopathy, or degenerative brain disease, which, if untreated, results in death. The most remarkable aspect about lead illnesses, notes HHS’s study, is that they are completely preventable.
Children Most Vulnerable
As a poison, lead has its most profound effects on rapidly growing biological systems. For humans, explains Graef, that means on the fragile, developing fetus, infant and child.
But several other factors also account for why children are so vulnerable to lead poisoning. Children’s behaviors and activities–putting their hands in their mouths, playing in dirt, and eating nonfood objects, for example–increase their exposure to lead, says Graef
In addition, he continues, children absorb more nutrients than adults do. They sometimes are deficient in iron, particularly in infancy, which increases their tendency to absorb more lead, and their rate of mineral uptake in bone is “several times greater than that in adults,” says Graef. “In every sense of the word, children and lead do not mix.”
Because of their unique risks, John Rosen, M.D., professor of pediatrics at Montefiore Medical Center, New York City, points out that lead consumption in childhood can mean a lower IQ and impairment in reading, writing, math, visual and motor skills, language, abstract thinking, and concentration.
Children may also suffer irritability, insomnia, colic, and anemia, all of which are subtle indications of elevated blood lead levels. Lead can also impair children’s growth.
Damage to the child’s nervous system is permanent, says LaDou, and some experts are now suggesting that low doses of lead may be responsible for some behavioral problems that most people call hyperactivity, as with the Puerto Rican child who could not sit still in the doctor’s office. Even the subtle effects may be permanent, says Sue Binder, M.D., chief of the Lead Poisoning Prevention Branch, the national Centers for Disease Control.
And, according to lead expert Herbert Needleman, M.D., professor of psychiatry and pediatrics at the University of Pittsburgh, “It is a reasonable assumption that 20 percent of delinquency is associated with lead intake.”
A 1988 report issued by the Agency for Toxic Substances and Disease Registry (ATSDR) estimates that between 3 million and 4 million children suffer from exposure to lead at concentrations that place them at risk of adverse health effects. The same report says that about 200,000 children more are actually lead poisoned. Mike Bolger, Ph.D., toxicologist at FDA’s Center for Food Safety and Applied Nutrition, says that now that most experts accept a lower standard for lead poisoning than was used in the ATSDR study, chances are that the number of children considered to be affected by lead will be higher. To date, Bolger adds, no estimates have been made of how many adults suffer from lead poisoning.
Fortunately, childhood deaths from severe lead poisoning have become very rare. The most recent case occurred at the Children’s Hospital of Wisconsin in Milwaukee in September 1990, when Eric Rivera died of lead poisoning after consuming quantities of leaded paint chips, probably over a period of time.
A new drug, recently approved by FDA, to chelate (or remove) lead from children may reduce illness and death from lead. Chelating agents work by binding to lead in the bloodstream and expediting its elimination from the body in urine. Before the development of Chemet (succimer), the only drug available to chelate lead was calcium disodium versenate (EDTA), which is administered intravenously in adults and by intramuscular injection in children. Chemet has been approved for use only in children who have lead levels above 45 micrograms per deciliter.
Chemet removes lead from the body while leaving essential trace elements. Although its use at present has been limited, its track record indicates that the new oral drug may prove to be invaluable: Chemet given every eight hours for five days to children with lead poisoning has produced a drop in blood lead levels up to 78 percent. The recommended treatment course lasts 19 days and does not require hospitalization. Presently, herapeutic intervention is considered only when lead body burdens are high–that is, greater than 25 micrograms per deciliter. The proposed labeling for this new drug warns that Chemet is “not a substitute for preventing further exposure to lead.”
Adults Also Benefit from Research
Although the scientific community has focused on helping children, adults have benefited from the efforts to reduce childhood lead poisoning, Bolger says. The health effects for adults may be almost as grim, although adults require larger quantities of lead to cause the same damaging effects.
Scientists know that lead attacks the adult’s peripheral nervous system, but its effects on the central nervous system have not been adequately studied, says Bolger. Protecting pregnant women and women of childbearing age is particularly important–their bone lead stores may be released into the bloodstream, exposing not only them to lead, but also their fetuses.
Because lead accumulates over a lifetime, points out Kathryn Mahaffey, Ph.D., science advisor in the office of the director, National Institute of Environmental Sciences in North Carolina, people may be carrying around in their bones deposits of a toxic chemical. And lead may reenter the bloodstream at any time as a result of severe biologic stress–such as renal failure, pregnancy, and even menopause–and from prolonged immobilization and very severe disease, says Richard Wedeen, M.D., associate chief of staff, research and development, V.A. Medical Center, East Orange, N.J., and author of Poison in the Pot: The Legacy of Lead.
Adults’ problems with lead may be difficult to recognize. “There’s a delayed effect and it is difficult to prove,” says Wedeen. “Lead may be linked to high blood pressure, strokes, and heart attacks as well as kidney disease.” In addition, Wedeen says, it impairs reproduction. And lowered IQ in childhood may result in adults who do not perform well and who become disruptive members of society. He asserts that it is reasonable to believe that lead contaminates every biochemical function.
There may be racial implications as well, says Wedeen. For example, black males are six times overrepresented in end-stage renal disease programs in our society–and these figures, hypothesizes Wedeen, may well be related to lead exposure. (He adds that it is a well-known fact that black male children have the highest lead exposure and blood lead levels of any group in the United States.) Because lead exposure is certainly not the only cause of hypertension and kidney disease, diagnosis is complicated and obscured.
Symptoms of lead exposure may not be identified unless the doctor does specific kinds of testing, he says. Many adults with mental symptoms due to lead encephalopathy may be misdiagnosed as alcoholics. Conversely, believes Wedeen, adults who suffer from acute lead poisoning may become alcoholics and end up in mental institutions.
Measuring the level of lead in blood is the most common way to estimate how much lead is circulating in the body at that moment. Because lead migrates to the bone several weeks after entering the bloodstream, a number of scientists are in favor of using a more precise technique for measuring the actual extent of lead accumulation and poisoning as measured in bone and teeth.
In the 1970s, scientists set the maximum safe blood lead level for adults at 45 micrograms per deciliter, and in 1985 for children at 25 micrograms per deciliter.
Since then, research has shown that adverse effects actually occur at far lower levels. Bolger says that for adults, lead toxicity is associated with blood lead levels as low as 30 micrograms per deciliter. For children, toxicity occurs at 10 micrograms per deciliter–a figure that CDC recognizes in a 1991 draft revision of an earlier statement in the booklet Preventing Lead Poisoning in Young Children: A Statement by the Centers for Disease Control–January 1985. He adds that researchers project that the average American carries about 5 to 6 micrograms per deciliter in the blood. “Because lead serves no known function in the body, the amount of lead that is ‘normal’ is about zero,” says Tom Matte, M.D., medical epidemiologist, Lead Poisoning Prevention Branch, CDC.
It’s Almost Everywhere
Once extracted from its naturally occurring state as an ore, lead has had thousands of applications–in gasoline and solder, paint, water pipes, housewares decorations, pottery glazes and lead crystal ware, power plant scrubbers, and lead-acid batteries, to name a few. Lead’s durability, malleability, mass, low melting point, and resistance to corrosion from many chemicals make it indispensable for many industries.
Jeffrey Zelms, chairman of the Lead Industries Association, Inc., says that the health impact of today’s lead is not a significant nor unreasonable risk. But some experts would disagree. Although lead is naturally present in the earth’s crust, its redistribution throughout the environment by industrial activities has become a global problem, says LaDou, adding, “Lead lasts forever in the environment,” because it is dispersed into air, soil, dust, and water.
It’s true that the most important environmental exposure today is coming from past uses of lead in solder, house paint, and car fuel, says Matte, and all those uses have been dramatically curtailed. But the legacy persists in the form of paint dust or chips in older homes where leaded paint still coats walls and as soil filled with lead particles emitted from leaded gasolines.
He continues that people should not take lightly any current commercial use of lead, such as bread wrappers that are labeled with inks containing lead pigments.
These wrappers are possible sources of lead ingestion when people turn them inside out and then use them for storing foods, points out Jerry Burke, director of FDA’s Office of Physical Sciences. However, if used for their intended purpose, the lead is not expected to contaminate the bread.
And lead can leach from certain items that come in contact with food–such as improperly manufactured ceramic products (usually imported), lead crystal ware decanters used for storing wine and other liquids, lead crystal baby bottles, and some decorated drinking glasses and mugs.
FDA Sets Standards
Many agencies, such as FDA, the Environmental Protection Agency, and CDC, and numerous private groups have been working for a long time to reduce lead levels in such primary sources as food, soil, water, dust, and air. Remarkable progress has been made in the past few years–most experts agree that blood lead levels in the general population have dropped dramatically since most leaded gasolines have been phased out, lead has been removed from interior house paints, and the number of foods packed in lead-soldered cans has been substantially reduced.
Replacement of lead solder in the manufacture of most food cans in the United States has had the most significant effect in reducing the amount of lead ingested by the average American, says Burke. As a result of ongoing dialogue with the American food canning industry, FDA has worked with food processors to change can design to eliminate use of lead solder. Since 1979, when about 90 percent of all American-produced food cans contained lead solder, the figure has dropped to a 1990 level of about 3.8 percent, and a spokesman for the food processing industry expects that after mid-1991 no lead-soldered food cans will be produced domestically.
Reducing lead levels in food sources or products in contact with food surfaces has long been a major FDA effort. FDA initiated an enforcement program on lead-based pesticides in fruits and vegetables in 1930. Since then, FDA has monitored dietary intake of lead in its Total Diet Study and worked with the U.S. food processing industry, leading to the packing of baby foods and juices in glass containers, the elimination of lead solder from evaporated milk cans, and reduction in use of lead-soldered food cans.
Limits were established on allowable amounts of lead leachable from ceramic products–both domestic and imported–and silver-plated holloware. As concerns about lead exposure have grown, FDA has continued to monitor food for lower levels of lead and is further evaluating a variety of potential sources of dietary lead, such as ceramic ware, decorated glassware, calcium supplements, lead-containing wine bottle seals, some older commercial coffee urns, and food ingredients.
The lead glaze on most ceramic foodware sold in the United States is formulated, applied and fired in such a way that the final product is impervious to the effects of food and beverages. But if improperly formulated and fired, the lead from the glaze leaches into foods.
FDA set up requirements on how glazes test out on the final product and began setting limits for lead leaching from ceramic products in 1970 after a California family suffered acute lead poisoning from drinking orange juice stored in a pitcher bought in Mexico. FDA has set the maximum allowable amount of leachable lead from ceramic ware at 7 parts per million (ppm) for flatware, 5 ppm for small holloware, and 2.5 ppm for large holloware–a drop from the 1970 limits set at 7 ppm for all ceramic products. In 1990, FDA proposed to further reduce limits to 0.1 ppm for large holloware, and it is planning to review other categories of ceramic ware.
Imported ceramic products have been a greater concern to FDA than those produced in the United States, because most violations of FDA standards have been from foreign sources. More than 60 percent of the ceramic foodware sold in the United States is imported from some 80 foreign countries.
FDA efforts are concentrated on testing ceramic products from countries with histories of violations of FDA standards. FDA also entered into an agreement in 1988 with the People’s Republic of China. This agreement requires that the Chinese government certify that shipments to the United States have been tested and that they meet FDA requirements. FDA now is working toward similar agreements with other countries, including Italy, Spain, and Hong Kong.
Recent preliminary studies conducted by researchers at Columbia University and at FDA have suggested that alcoholic and some other beverages stored for prolonged periods in crystal ware decanters may leach lead from the crystal. Pending completion of more comprehensive studies conducted by FDA and the crystal ware industry, consumers may want to avoid storing foods or beverages in crystal glassware for extended periods. This advice is especially important for pregnant women and infants and children.
Road Map to the Future
In the ongoing battle against lead exposure and lead poisoning, HHS’s 1991 Strategic Plan is intended as a road map to guide future programs. While elements of the plan are already in effect–reducing lead in paint, drinking water, and food, for example–authors of the plan convey a sense of urgency. As pointed out in the plan’s preface, lead poisoning “has already affected millions of children, and it could affect millions more. Its impact on children is real, however silently it damages their brains and limits their abilities.”
As for its role, although it can count many successes, FDA is stepping up its lead efforts, says Burke. “We have recognized the increase in concern about lead exposure, and we are taking steps on a number of fronts that will reduce the potential for exposure,” he says. FDA has set out a four-part approach that includes issuing regulations to reduce or eliminate certain lead sources; increasing cooperative and voluntary control activities with affected industries; developing information on effectiveness of existing controls and needs for new ones; and educating the public.
In the end, with a concerted national effort, lead poisoning can be eliminated within the next few decades.
Alexandra Greeley is a freelance writer in Reston, Va., has written on food for Time-Life books, Newsday, and the South China Morning Post.
Who’s Doing What
The following list includes many of the agencies–and their areas of responsibility–involved with regulating lead exposure or researching the effect lead.
FDA has responsibility for regulating lead in:
* bottled water
* calcium supplements
* ceramic and other foodware
* commercial coffee urns
* decorated glassware
* food, including ingredients and packaging
* lead crystal
* lead-soldered food cans.
EPA (Environmental Protection Agency) researches and/or monitors lead content in air, water and soil, and has some involvement monitoring lead-based paints.
NIOSH (National Institute for Occupational Safety and Health) conducts research and surveillance on occupational lead exposure and offers health hazard evaluation programs on work sites when requested and industrial hygiene training.
OSHA (Occupational Safety and Health Administration) regulates lead exposure at the work site.
NIEHS (National Institute of Environmental Health Sciences) conducts basic biomedical research on human health effects of lead. HUD (U.S. Department of Housing and Urban Development) funds public housing authorities to contain or remove lead-based paint in public housing units.
CPSC (Consumer Product Safety Commission) requires warning labels on lead solder for drinking water pipes; monitors lead paint on children’s toys to ensure compliance with the federal standard limiting lead in paint to no more than 0.06 percent; regulates the labeling of artists’ materials; and has issued safety warnings about hazards of use of lead-based paint in the home.
ATSDR (Agency for Toxic Substances and Disease Registry) is responsible for health assessment for areas near Superfund sites (toxic waste sites that pose an environmental threat); wrote case study on lead for health professionals; and authored 1988 congressional document about the nature and extent of lead poisoning of American children.
How to Avoid Lead Exposure
Lead may be almost everywhere, but consumers can take practical steps to limit their exposure to it. Several experts give the following advice:
Food and Food-Related Products
* Make sure children’s hands are clean before they eat.
* If using leaded crystal ware for drinking, do not use it on a daily basis, do not store liquids in it, do not use it while pregnant, and do not let children use it. Lead crystal baby bottles should not be used for infant feeding.
* Some imported foods are still packed in lead-soldered cans. If your grocer cannot assure you that a particular product is not packed in a lead-soldered can, your best bet is to limit consumption of imported canned foods.
* If using older or imported ceramic products, avoid storing acidic foods in them or, better yet, have them tested. If they test high in lead, use only for decorative purposes or discontinue use or dispose of the item. There are at least four home lead test kits on the market:
* Test For Lead In Pottery ($25) and The FRANDON Lead Alert Kit ($29.95), Frandon Enterprises Inc., P.O. Box 300321, Seattle, Wash. 98103, or (1-800) 359-9000.
* LeadCheck Swabs ($25) or LeadCheck Swabs-Half Packs ($15), HybriVet Systems, Inc., P.O. Box 1210, Framingham, Mass. 01701, or (1-800) 262-LEAD.
* LeadTest ($10), Verify, Inc., 1185 Chess Drive, Suite 202, Foster City, Calif. 94404-1109, or (1-415) 578-9401.
* LEADCHECK II ($25), distributed by Michigan Ceramic Supplies, 4048 Seventh St., P.O. Box 342, Wyandotte, Mich. 48192, or (1-313) 281-2300.
Although lead-based paints have been banned for use in residences, numerous older private homes and public housing units still contain these paints. As a precaution:
* Keep painted surfaces in good repair so that older layers of paint are not exposed, chipping or peeling.
* Do not allow children to eat paint chips.
* Hire only a professional contractor to remove lead-based paints from any surface. People can poison themselves by burning or scraping off layers of paint. Lead dust is generated and if not contained properly sticks to household surfaces and is dispersed into the air.
In order for your water to contain lead, there must be a source, such as lead service lines to the house, brass faucets, and/or lead solder on water pipes. Jeff Cohen, chief of the Lead Task Force, at EPA’s Office of Water, says that lead is not a hazard in everyone’s home because, in general, lead levels in drinking water are low. But he says that concerned homeowners or apartment dwellers can take several steps to reduce lead content in water:
* Begin with a water analysis–usually available at a cost of $15–on your household water. Do not run the water for six to eight hours before testing–lead may leach from pipes into still water.
* If the analysis shows that lead levels are about 20 ppb or higher, let water run before first use in the morning for 30 seconds or until the water runs cool. This flushes the lines. Do not use hot water for drinking or cooking since lead leaches more easily into hot water.
* To take further action, call your local water supplier to find out if your home/apartment is connected to the water main by lead service connections. If so, and if the service lines belong to the water supplier, ask if they have plans to replace the lines. If you own the lines, the supplier can help locate the name of a contractor to change them. Never use lead solder to repair plumbing.
COPYRIGHT 1991 U.S. Government Printing Office
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