Lead by Ray Sahelian, M.D. certified natural health professional - Information on Lead and Health

Lead is a highly toxic metal or mineral that was used for many years in products found in and around the home. Lead may cause a range of health effects, from behavioral problems and learning disabilities, to seizures and death. Children 6 years old and under are most at risk, because their bodies are growing quickly. Lead can accumulate in the body as a body toxins.

Lead Exposure in Children

Teenagers whose blood levels of lead were relatively high as children may be more prone to falls and injuries. The toxic metal is already known to be particularly dangerous for young children and fetuses, as even low-level exposure can damage the developing brain and cause learning and behavioral problems. The primary sources of lead exposure for most children are:
- deteriorating lead-based paint,
- lead contaminated dust, and
- lead contaminated residential soil.

   A new blood test that measures lead exposure and gives results in three minutes is made by privately held Magellan Biosciences Inc.. This lead exposure test improves on older ones that had to be sent to a laboratory and could take two weeks or more to deliver results. The new lead exposre test could be especially useful for health-care workers who test children in schools for lead exposure. Blood is drawn by pricking a finger and results are produced in three minutes. High levels of lead exposure can cause brain damage and other problems, particularly in young children.
   About one-third of ADHD cases among U.S. children may be linked with tobacco smoke before birth or to lead exposure afterward. Even levels of lead the government considers acceptable appeared to increase a child's risk of having attention deficit hyperactivity disorder.

Lead in homes
Despite laws designed to rid homes of hazardous lead sources, many children with lead poisoning continue to live in unsafe conditions well after the danger is detected. In a study that followed 382 Wisconsin children with elevated blood lead levels, researchers found that it often took more than 18 months for the children's homes to be made "lead-safe." In only 18 percent of cases was the lead clean-up done within 6 months. In most U.S. states, cases of high lead levels among young children are reported to a state surveillance system. From there, it's usually the job of the local health department to inspect the child's home -- the most likely source of the lead exposure. Deteriorating lead-based paint, which is still present in some older homes and apartment buildings, is a chief source. If a home has hazardous lead levels, officials issue an order that the lead source be completely removed or otherwise addressed -- by covering lead-based paint, for instance. Lack of money is probably one reason driving the delays, according to the researcher. Even landlords, she noted, may not have the money to quickly clean up lead problems, and there's no national program to help them pay. American Journal of Public Health, February 2006.

Lead Exposure in Adults

Lead is commonly added to industrial paints because of its characteristic to resist corrosion. Industries with particularly high potential exposures include: construction work involving welding, cutting, brazing, blasting, etc., on lead paint surfaces; most smelter operations either as a trace contaminant or as a major product; secondary lead smelters where lead is recovered from batteries; radiator repair shops; and firing ranges.

Lead and Health

Lead enters the body either through ingestion or inhalation. Once in the blood, lead is distributed primarily among three compartments – blood, soft tissue (kidney, bone marrow, liver, and brain) and mineralizing tissue (bones and teeth). Absorption via the GI track following ingestion is highly dependent upon presence of levels of calcium, iron, fats and proteins.

Lead and Blood Pressure

High levels of lead in the blood and in bone seem to raise the likelihood of developing high blood pressure, but this may be related in part to low levels of calcium in the diet. Dr. Barbara S. Glenn, from the US Environmental Protection Agency in Washington, DC, and colleagues show that blood pressure responds relatively quickly to changes in lead levels. The study involved 575 people in South Korea who had worked for an average of 8.5 years in a job that exposed them to lead. The authors found that as lead levels changed on a yearly basis, so did blood pressure. This suggests that it is not just the cumulative lead dose over a lifetime that influences blood pressure. In a second study, Dr. Howard Hu, from the Harvard School of Public Health in Boston, and colleagues looked at how dietary calcium affects the link between lead levels and blood pressure. Bone and blood lead levels were associated with hypertension only among subjects with low calcium intake, defined as less than 800 milligrams daily.
    

Lead Poisoning
Lead poisoning affects nearly every system in the body. The complete development of the blood-brain barrier in fetuses and very young children (up to three years of age) increases the risk of lead entering the nervous system. Low but chronic exposure can affect the developing nervous systems in subtle but persistent ways. In children, blood lead levels as low as 10 to 15 ug/dL can stunt growth rates, affect attention span, cause learning disabilities, lower IQ scores, impair hearing perception, and cause behavioral problems. In addition to damaging the nervous system, elevated blood lead levels can also affect the kidneys and reproductive system, and cause high blood pressure.

Diagnosis of lead poisoning is difficult
Lead poisoning can be a slow, agonizing process or a swift killer with symptoms ranging from vomiting to bulges in the skull that can fool doctors. Lead is toxic if ingested and is often found in older homes containing lead -based paint, which has since been phased out. Objects such as toys and charm bracelets may also contain the metal and pose a threat to children who swallow them. Children with mild but chronic lead poisoning may show few symptoms but can suffer permanent brain damage. Children with more significant acute lead intoxication can present with more severe symptoms such as irritability, lethargy, vomiting, seizures, and coma. Another lead poisoning symptom to watch for is bulging in the soft spots or seams in the still-growing skull of young children. Lead poisoning should also be considered by doctors when the patient exhibits vomiting, developmental delays, hearing loss, behavioral problems, seizures, or anemia.

Lead Exposure and Brain
The cumulative exposure to lead can cause degeneration of the brain's white matter, which may explain the  progressive decline in brain function in organic lead workers. The brain's white matter contains nerve fibers, with many of these fibers, or "axons," surrounded by substance called myelin, the source of the whitish appearance. Myelin acts as an insulator and it increases the speed of transmission of all nerve signals. The more a worker is exposed to lead on the job, as measured by the amount of the metal found in the bone, the worse the brain damage many years later, mainly in the form severe and extensive white matter abnormalities in the brain. Greater lead exposure is also associated with a smaller brain volume, while specific regions of the brain also shrink after greater lead exposure. Neurology, May 23, 2006.

Lead exposure and mental decline
The higher the cumulative exposure to lead in everyday life, the lower scores on a variety of cognitive tests -- and the worse the mental deterioration over time. Dr. Marc G. Weisskopf, of Harvard School of Public Health, Boston, Massachusetts, and colleagues examined the link between mental skills and life-time lead exposure among a subgroup of subjects in the Normative Aging Study, a cohort of community-dwelling elderly men. None of the men studied had dealt with high levels of lead in their work. Lead concentrations in blood and bone were measured from 1991 through 1999. Cognitive testing was performed from 1993 through 2001. At the beginning of the study, the average blood lead concentration was 5 micrograms (µg) per deciliter. The average lead concentration in the kneecap, measured by an x-ray technique, was 20 µg per gram of bone mineral. As blood lead levels increased, vocabulary scores went down. Above concentrations of 10 µg per dL, scores declined about 1 point for every µg/dL increase in lead level. Epidemiology, January 2007.

Lead exposure and crime
Exposure to lead in early childhood or in the womb can cause permanent brain damage that may even cause criminal behavior.

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Lead contamination in multivitamin
January 2007 - Of 21 brands of multivitamins on the market in the United States and Canada selected by ConsumerLab.com and tested by independent laboratories, 10 multivitamin brands met the stated claims on their labels or satisfied other quality standards. Most worrisome, according to ConsumerLab.com president Dr. Tod Cooperman, is that one product, The Vitamin Shoppe Multivitamins Especially for Women, was contaminated with lead. The Vitamin Shoppe women's product contained 15.3 micrograms of lead per daily serving of two tablets. This amount of lead is more than 10 times the amount permitted without a warning in California, the only state that regulates lead in supplements, Cooperman said. On average, most American adults are exposed to about 3 micrograms of lead through food, wine and other sources, he said, and while 15.3 micrograms of lead per day may not be immediately toxic, the mineral is stored in the body and could build up to dangerous levels with time. "I would be concerned about a woman taking a multivitamin that contains 15.3 micrograms of lead per daily serving," said Judy Simon, a dietitian at the University of Washington Medical Center in Seattle. Among other effects, she said, lead can contribute to high blood pressure. David Morrison, vice president of scientific and regulatory affairs at The Vitamin Shoppe, said his company's products are all tested more than once, including screening for lead, and he questioned the new results. "It would be very surprising to me if this were actually true," he said. ConsumerLab.com also tested a vitamin marketed for dogs called Pet-Tabs Complete Daily Vitamin-Mineral Supplement for Dogs and found the product was contaminated with 1.4 micrograms of lead per tablet.

Lead contamination questions
Q. I recently bought a bottle of women's multi which had the disclaimer "this product contains lead". I went back to the store and asked the clerk in the vitamin dept why, and he said it was because of the Vanadium. Is this true or is the lead caused by something else? Three pills gives 9 mcg of Vanadium. Would you suggest I return this and look for a brand that doesn't have lead? Do you know of some brands that do not have lead.
   A. Lead and vanadium are different minerals, we don't see the connection between the two. There is a small amount of lead in many products we ingest and we are exposed to lead through inhaling of pollutants. The amount of lead in the multivitamin could make a difference. If it is a tiny amount, it may not effect health, but if the lead is present in significant amounts, it could be harmful. MultiVit Rx does not have lead in it.