Lead and the Brain
              John D. MacArthur


MAINPAGE
http://sln.fi.edu/brain/lead/lowIQ.html

               For centuries, lead contamination has undermined intelligence and debased
               behavior. Only now are we beginning to fully understand how this heavy metal
               damages the brain, especially the prefrontal cortex, that fragile headquarters of our
               humanity.

               A Leaden History

                    "Dear Friend,
                    I recollect that, when I had the great Pleasure of seeing you at
                    Southampton, now a 12 months since, we had some Conversation on
                    the bad Effects of Lead taken inwardly; and that at your Request I
                    promis'd to send you in writing a particular account of several Facts I
                    there mentioned to you, of which you thought some good use might
                    be made. I now sit down to fulfill that Promise."

               So begins a letter written by Benjamin Franklin to Benjamin Vaughan on July 31,
               1786. His recollection of lead's dangers begins in his boyhood Boston, where rum
               distilleries were prohibited from using leaden still-heads because they contaminated
               the rum with lead causing people to lose the use of their limbs.

               Later, as an 18-year old printer's compositor in London, advice of an old workman
               may have preserved Franklin's future ability to write. He discouraged young
               Benjamin from warming the cases of leaden types before the fire. Although it made
               the cold metal easier to handle, others who followed the practice had met with
               disaster:

                    "One of whom that used to earn his Guinea a Week, could not then
                    make more than ten shillings, and the other, who had the Dangles, but
                    seven and sixpence. This, with a kind of obscure Pain, that I had
                    sometimes felt, as it were in the Bones of my Hand when working
                    over the Types made very hot, induced me to omit the Practice."

               Flash Forward
               In 1998 the Centers for Disease Control and Prevention (CDCP) reported that
               nearly a million American children between the ages of one and five have the toxic
               metal lead in their blood at concentrations above 10 micrograms per deciliter
               (ug/dL), the current threshold of safety established in 1991. [1] This was chosen as
               the "unsafe" level mainly because it was the lowest level that could be detected with
               an inexpensive test. According to the CDCP, setting the standard lower would
               burden the country's healthcare system. [2]

               Actually, there is no safe dose of lead in children's blood. After summarizing the
               research, in 1993 the National Research Council concluded "there is growing
               evidence that there is no effective threshold for some of the adverse effects of lead.
               . . . Even very small exposures to lead can produce subtle effects in humans." [3]

               Lead Affects Children the Most
               Lead in the body can cause permanent damage to the central nervous system, the
               brain, and kidneys. This commonly results in behavior and learning problems,
               hearing problems, headaches, high blood pressure, slowed growth, reproductive
               problems, digestive problems, muscle and joint pain. The effects of lead poisoning
               are cumulative and can last a lifetime. They are usually irreversible especially in
               sensitive populations such as fetuses, children, and pregnant women.

               Lead is most devastating to unborn children, because the "placental barrier" does
               not protect the developing fetus from lead in maternal blood. This placental transfer
               of lead begins as early as the 12th week of gestation and continues throughout fetal
               development. [4]

               The risk of spontaneous abortion nearly doubles for every 5 ug/dL increase in
               blood lead levels, according to the results of a two-year Mexican study reported in
               the Sept. 15, 1999 issue of the American Journal of Epidemiology.

               Lead Lowers Intelligence
               In 1995, the American Academy of Pediatrics reviewed 18 scientific studies on the
               correlation between children's mental abilities and lead in their blood. "The
               relationship between lead levels and IQ deficits was found to be remarkably
               consistent," the Academy said. "A number of studies have found that for every 10
               ug/dL increase in blood lead levels, there was a lowering of mean IQ in children by
               4 to 7 points." [5]

               This drop has staggering implications. As Theo Coburn describes in her landmark
               1994 book, Our Stolen Future:

                    "With the current average IQ score of 100, a population of 100
                    million will have 2.3 million intellectually gifted people who score
                    above 130. Though it might not sound like much, if the average were
                    to drop just five points to 95 . . . only 990,000 would score above
                    130, so this society would have lost more than half its high-powered
                    minds with the capacity to become the most gifted doctors, scientists,
                    college professors, inventors, or writers.

                    "At the same time, this downward shift would result in a greater
                    number of slow learners, with IQ scores around 70, who would
                    require special remedial education, an already costly educational
                    burden, and who may not be able to fill many of the more highly
                    skilled jobs in a technological society. Given the daunting array of
                    problems we face as nations and as a world community, the last thing
                    we can afford is the loss of human intelligence and problem-solving
                    powers."

               Attention-Deficits
               A 1996 study at the University of Massachusetts evaluated the relationship
               between lead levels in the hair of children and their attention-deficit behaviors in the
               classroom. It found a "striking dose-response relationship between levels of lead
               and negative teacher ratings. . . An even stronger relationship existed between
               physician-diagnosed attention-deficit hyperactivity disorder and hair lead in the
               same children." [6] A similar study done at Vrije Universiteit of Amsterdam found
               that children with relatively high concentrations of lead in their hair "were
               significantly less flexible in changing their focus of attention." [7]

               Experiments at the University of Rochester School of Medicine found that animals
               exposed to lead exhibited behaviors similar those observed in children diagnosed
               with attention deficit hyperactivity disorder "impulsivity" and "inability to inhibit
               inappropriate responding." [8]

               (Other environmental factors for ADHD are discussed in "The Attention-Deficit
               Dilemma," in this website.)

               International Crisis
               The results of a two-year study conducted in India found that more than 50% of
               children under 12 had blood lead levels higher than 10 micrograms per deciliter!
               "Project Lead-Free" was conducted in six major Indian cities and involved nearly
               22,000 children, including toddlers, slum children, working children, school children
               in low and high economic groups, and pregnant women.

               These findings were presented in February 1999 at an international conference on
               lead poisoning held in Bangalore, where the World Health Organization estimated
               that 15 to 18 million children in developing countries are suffering from permanent
               brain damage due to lead poisoning. The greatest source of poisoning is leaded
               gasoline. Paints, cooking utensils, and drinking water systems are other primary
               sources.

               These countries are only now beginning to address the problem, which is extremely
               serious according to Dr. Herbert L. Needleman, professor of psychiatry and
               pediatrics at the University of Pittsburgh. "Blood lead levels are terribly high in
               India, Bangladesh. . . . China has a serious problem and so does Russia," he said.
               [9]

               How Lead Violates the Brain
               In their 1998 investigation into lead's effects on the brains of children, Israeli
               researchers found that, for starters, lead disrupts the main structural components of
               the blood-brain barrier, (by injuring the glial brain cells that surround and protect
               neurons and by damaging the capillaries that keep toxins out of the brain).

               Once in the brain, lead-induced damage occurs primarily in the prefrontal cerebral
               cortex, cerebellum, and hippocampus. There it adversely affects many biological
               activities at the molecular, cellular, and intracellular levels.

               Writing in the July 1998 issue of Brain Research, neurologists at Shaare Zedek
               Medical Center in Jerusalem reported that lead interferes with the action of calcium
               and with the neurotransmitter systems that are crucial to regulating emotional
               response, memory, and learning.

               They found a direct link between low-level long-term exposure to lead and deficits
               in cognitive performance and behavior in childhood through adolescence. They also
               concluded that "there is no threshold below which lead remains without effect on
               the central nervous system."

               Since learning requires the remodeling of the brain's synapses the spaces
               between neurons where information is exchanged lead may specifically affect
               synaptic transmission. In 1999, neurologists at Johns Hopkins University School of
               Public Health proposed that the learning deficits caused by lead are due to its
               disruption of processes regulated by calcium (protein kinase C) at the synapse.
               [10]

               Lead and Dementia
               Animal studies done in the 1980s showed that lead inhibits myelination and
               microtubule assembly in the brain, as well as caused the formation of fibers and
               "aggregates of amorphous material." [11] This suggests that lead may be involved in
               senile dementia, although little research has been done in this area.

               The November 1998 issue of the journal Epidemiology published a report titled,
               "Is chronic low-level lead exposure in early life an etiologic factor in Alzheimer's
               disease?" According to Dr. Prince at the London School of Hygiene and Tropical
               Medicine and the Institute of Psychiatry, England:

                    "Few environmental risk factors for Alzheimer's disease have been
                    identified. This lack of information may reflect the fact that salient
                    factors affect most of the population in developed countries.
                    Furthermore, the critical period of exposure may be earlier than
                    hitherto suspected, during the first years of life, as the brain
                    differentiates and develops. Exposure to lead at levels lower than
                    those associated with evident toxicity causes mild intellectual
                    impairment in childhood. I hypothesize that this may be one of the
                    childhood exposures that also confers an additional risk for the onset
                    of Alzheimer's disease."

               The Prefrontal Cortex and Your Moral Imperative
               Your prefrontal cortex is the most human part of your brain. One of the things it
               allows you do is to see things from a different point of view, to walk in someone
               else's shoes in a word, empathy. Since the 1980s, scientists have correlated
               damage to the prefrontal cortex with psychopathic behavior and the inability to
               make morally and socially acceptable decisions.

               Swedish researchers have found that the prefrontal cortex is precisely the area of
               the brain that is is impaired in murderers, rapists, and other violent criminals who
               repeatedly re-offend. At the November 1999 annual meeting of the Society for
               Neuroscience, Asa Bergvall and her colleagues from the University in Sweden
               presented findings on their study of violent offenders.

               The results were quite startling."The violent offenders are like the controls in every
               task but one, which taps prefrontal function," says Bergvall. "In that, it was as if
               they were retarded." They had an impaired ability to shift their attention in order to
               view the world in a different way a function linked to the lateral prefrontal
               cortex. Other, higher order executive functions of their prefrontal cortex appeared
               to be unimpaired.

               Childhood Damage to the Prefrontal Cortex is the Worst
               In a related presentation at the Society for Neuroscience meeting, researchers
               reported that children who experience early prefrontal damage never completely
               develop social or moral reasoning. Even on an intellectual level they cannot refer to
               such behavior because they have little concept of it.

               In contrast, individuals with adult-acquired damage are usually aware of what
               proper social and moral behavior should be. However, they are unable to act upon
               it. Even though they have an intellectual memory of learned moral conduct, they
               cannot apply such behaviors.

               A study at University of Iowa College of Medicine, published in the November
               1999 Nature Neuroscience, reports on two cases of early brain damage to the
               prefrontal cortex, in which the patients as adults showed the same two distinctive
               features: an almost total lack of guilt and an inability to plan for the future but
               were normal in almost every other type of mental ability.

               The patients had problems with violence and "resemble psychopathic individuals,
               who are characterized by high levels of aggression and antisocial behavior
               performed without guilt or empathy for their victims," wrote Raymond Dolan of
               Institute of Neurology in London in an editorial that accompanied the research.
               Their brains were just not capable of acquiring social and moral knowledge even at
               a normal level.

               Unlike other areas of the brain, the prefrontal cortex is not particularly plastic. If the
               area responsible for moral and social awareness is damaged in childhood, it can
               never develop. Dolan suggested that this understanding of the brain will require a
               reappraisal of the way society deals with criminal behavior, because "problems with
               moral and social behavior may be rooted in physical problems in the brain."

               As New York physician Dr. Charles Gant describes it: In evolutionary terms the
               prefrontal cortex is "the last part of the human brain to develop and is one of the
               first parts to lose its function when there is a generalized stress or injury to the
               central nervous system. Because this recent brain structure has not had the benefit
               of millions of extra years of 'road testing,' that the older, more rugged parts of the
               brain have had, it is more vulnerable to modern-era stress, neurotoxins, and
               nutritional deficiencies." [12]

               Our Old Enemy, Lead, has a New Ally
               Important ongoing research has revealed a widespread, serious risk co-factor for
               lead poisoning. And it is reminiscent of an incident described by Benjamin Franklin
               in his letter:

                    "But I have been told of a case in Europe, I forget the Place, where a
                    whole Family was afflicted with what we call Dry Bellyache, or Colica
                    Pictonum, by drinking Rain Water. It was at a Country-Seat, which
                    being situated too high to have the Advantage of a Well, was supply'd
                    with Water from a Tank, which received the Water from the leaded
                    Roofs. This had been drunk several Years without Mischief; but some
                    young Trees planted near the House growing up above the Roof, and
                    shedding the Leaves upon it, it was suppos'd that an Acid in those
                    Leaves had corroded the Lead they cover'd and furnished the Water
                    of that with its baneful Particles and Qualities."

               Today's acid rain is not the only factor increasing lead contamination. Researchers
               at Dartmouth University found that certain chemicals being added to our drinking
               water are magnifying the uptake of lead and other toxic metals into the body and
               brain. Analyzing a major survey of more than 280,000 Massachusetts children, the
               team headed by Prof. Roger D. Masters has identified corrosive chemicals widely
               used in the fluoridation of public water supplies that apparently increase children's
               absorption of lead.

               Fluoridation Increases Lead Uptake
               The culprits are silicofluorides fluosilicic acid and sodium silicofluoride the
               chemicals used in more than 90% of America's fluoridated drinking water systems.
               In their study published in the October 1999 International Journal of
               Environmental Studies, the Dartmouth researchers show that children's blood
               lead is significantly higher in Massachusetts communities using silicofluorides than in
               towns where water is treated with sodium fluoride or not fluoridated at all.
               Compared to a matched group of 30 towns that do not use silicofluorides, children
               in 30 communities that use these chemicals were over twice as likely to have more
               than 10 ug/dL of lead in their blood.

               "Silicofluorides are largely untested," Professor Masters explains. "Virtually all
               research on fluoridation safety has focused on sodium fluoride, even though the
               studies in the 1930s showed important biological differences between these
               chemicals."

               Since completing the Massachusetts study, the Dartmouth group further confirmed
               the link between silicofluorides and elevated blood-lead levels based on data
               from rural counties in six additional states, as well as from a survey of more than
               120,000 children in New York towns and from the Third National Health and
               Nutrition Evaluation Survey (NHANES III).

               History Repeats Itself
               Just like the acidic leaves that leeched lead from the paint on that 18th century roof,
               fluosilicic acid leaches lead from plumbing. This was graphically demonstrated in
               two communities that stopped fluoridating their water systems. Their lead levels
               dropped significantly.

               During a 1992 drought in Tacoma, Washington, they temporarily stopped
               fluoridating their water and lead levels dropped from 32 ppb (parts per billion) to
               17 ppb. When Thurmont, Maryland stopped fluoridating their drinking water in
               1994, the lead level in homes dropped from 30 ppb to 7 ppb. (The EPA's
               Maximum Contaminant Level is 15 ppb.) [13]

               More than 98% of U.S. homes have lead in their plumbing systems. It comes from
               lead pipes, or copper pipes connected by lead solder, and from brass faucets,
               which also contain lead . Most chrome plated faucets are made of brass which is
               permitted to contain as much as 8% lead.

               Poisoning the Well Lead, Drugs, and Violence
               According to Prof. Masters, who heads the Dartmouth Foundation for
               Neuroscience and Society, "Through one of several plausible mechanisms, SiF
               [silicofluoride] treated water can increase the transport of heavy metals across the
               gut-blood and blood-brain barriers, increasing rates of toxic uptake and behavioral
               disfunction."

               On Sept. 2, 1999 at the Annual Conference of the Association for Politics and the
               Life Sciences, Prof. Masters gave the Plenary Address: "Poisoning the Well:
               Neurotoxic Metals, Water Treatment, and Human Behavior." He said the problem
               is especially serious because lead poisoning is associated with higher rates of
               learning disabilities, hyperactivity, substance abuse, and crime. Children who have
               been poisoned by lead are less able to handle stress and are more prone to violent
               outbursts.

               Silicofluorides and Violence
               Heavy metals damage neurons and "compromise normal brain development and
               neurotransmitter function, leading to long-term deficits in learning and social
               behavior," says Masters. Lead blocks the action of calcium atoms in the synthesis
               of serotonin and dopamine, neurotransmitters essential to normal impulse control
               and the suppression of violent behavior.

               Where silicofluorides were used to fluoridate water, risk-ratios for blood lead over
               10 ug/dL are from 1.25 to 2.5 more than doubled. Silicofluorides are thus
               ultimately responsible for more aggressive behavior among people who consume
               fluoridated water including the soft drinks, juices, and foods made with
               fluoridated water and whose diets are lacking in calcium.

               After an analysis of 129 rural communities in Georgia, Masters also found that
               "communities using silicofluorides also report higher rates of learning disabilities,
               ADHD, violent crime, and criminals who were using cocaine at the time of arrest."
               This makes sense because lead depresses dopamine levels in the brain, and
               cocaine addiction is associated with low levels of dopamine.

               An Old Story Rome
               Throughout history lead has been intimately related to plumbing. On the periodic
               table of elements, the symbol for lead is "Pb" short for plumbum the Latin
               word for plumbing. In ancient Italy magnificent aqueducts carried water from the
               mountains, supplying the people of Rome with 220 million gallons of water per day.
               Inside the city, water was distributed by lead pipes. The diameter of the pipe
               determined the cost of water, which flowed continuously. There were no faucets.

               The Romans also used lead to halt the fermentation of wines and to preserve food.
               Their drinking vessels and cookware were coated with lead glazes. (Ceramics are
               still a source of lead exposure in modern times.)

               Evidence still exists of the Romans' huge lead mining operations two millennia ago
               in southwestern Spain. Researchers have detected lead concentrations in core
               samples taken from Greenland's ice, evidence of large-scale pollution of Earth's
               atmosphere that peaked between 150 B.C. and 50 A.D., the height of Roman
               mining activity. "Lead pollution levels during the Roman era were about four times
               greater than natural background levels of lead but were still low by modern
               standards. Between the 1930s and 1970s, the lead concentration in the ice was 25
               to 50-times higher than during Roman times, due in large part to leaded gasoline."
               [14]

               Dr. Herbert L. Needleman, a leading researcher on the effects of low-level lead
               exposure, notes that the "increase in psychiatric disturbance in upper class Romans
               may have been related to lead exposure from plumbing and wine additives and thus
               was in part responsible for the decline of Rome." [15]

               Tin cans sealed with lead were once a major source of contamination. In the 1840s
               a famous expedition trying to find the Northwest Passage became lost. More than
               140 years later their bodies were finally found. The entire group had been poisoned
               to death by the lead in their cans of food. First, sleeplessness and irrational
               behavior overtook them. Then death came when the lead blocked the enzyme
               responsible for hemoglobin production, and their kidneys failed.

               Sources of Lead Exposure this Century
               In "The Story of Lead," Peter Montague reports: "The period of greatest lead use
               was 1945-1971, after which it began to decline. In those years, 165,000 to
               275,000 tons of lead dust spewed from the exhaust pipes of American automobiles
               each year. Americans born during these years have 300 to 1000 times as much
               lead in their bodies as pre-Columbian indigenous people had. Thus the generation
               of decision-makers in power today in government and in corporations is
               made up of people who are suffering mental irritability and dysfunction as a result of
               severe chronic lead insult. Reviewing the history of the past 25 years, it seems clear
               that the nation and the world have already paid a terrible price for their irritability
               and dysfunction. Leadership by the most lead-damaged (those born around 1970)
               lies just ahead." [16]

               The CDCP's 1998 study reported that the average concentration of lead in all 20
               million American preschoolers was 2.7 ug/dL, or 43 times as high as the natural
               background. [1] The 10 ug/dL now established as "safe" for children is 625 times
               greater than the average lead level in the bodies of the pre-Columbian inhabitants of
               North America. [17]

               The EPA permits our drinking water to have 15 ppb, but according to one of their
               own studies: "Drinking water supplied to 30 million people in 819 cities contains
               unhealthy levels of lead." [18]

               "Cover the Earth"
               In the United States, paint is now the chief source of the lead that poisons children.
               Leaded paint is still very common in older houses. More than 80% of U.S. housing
               built before 1980 contain some lead-based paints. In particular, white paint used to
               be made with lead carbonate and yellow paint from lead chromate.

               Although lead and mercury, another toxic metal, are no longer allowed in paint,
               other chemicals continue their legacy. According to their labels, certain paints
               contain solvents that "can cause permanent brain and nervous system damage." For
               some strange reason, paint seems to be the delivery system of choice for brain
               damage. (Will future archeologists be baffled by a society whose walls were more
               vibrant than its brain cells?)

               In October 1999, the state of Rhode Island sued eight of the nation's largest paint
               companies for marketing lead-based paints that are poisoning thousands of
               children. Atty. Gen. Sheldon Whitehouse said that nearly 20% of Rhode Island
               children entering kindergarten had elevated lead levels, and "it's time to force those
               who made the mess to clean it up."

               According to a report in The Providence Journal (Oct. 16), Whitehouse says the
               paint industry knew about the dangers of lead since the 1930s. He quotes industry
               officials in the 1950s who referred to lead poisoning as "mainly a problem in the
               slums and voicing more concerns over bad publicity than over the victims." What's
               worse, "paint company publicity extolled the health benefits and safety of lead
               paints."

               Another source of lead is vinyl mini-blinds made in Asia and Mexico. Laboratory
               tests show that when these particular mini-blinds deteriorate, their dust contains
               high levels of lead that can end up on children's hands and in their mouths. Also,
               candles with lead in their wicks have been shown to produce unhealthy levels of
               lead in the air for many hours even after the candle is no longer burning.

               Environmental lead exposure from industrial pollution and lead residues in soil
               further add to the accumulating burden of lead in the body and brain.

               Getting the Lead Out
               Oral or intravenous chelation therapy is the primary means for mobilizing lead and
               other heavy metals from the body, according to Dr. Walter J. Crinnion, a
               naturopathic physician who teaches environmental toxicity at Bastyr University in
               Seattle. Since 1987 he has operated the most comprehensive cleansing protocol in
               the nation and has found that "Diets high in the pectins and foods high in sulfur
               containing amino acids (methionine, cysteine) such as onions, garlic and beans can
               help. Sweating also helps to some extent." [4]

               And, based on the 1999 Dartmouth study, it would be wise to avoid water treated
               with caustic fluoride compounds.

               Ending the Violence of Lead
               The time has come to acknowledge the real dangers of lead contamination. Lead
               threatens civility and compromises critical thinking at the very time when these
               qualities are needed the most. Lead impairs our ability to distinguish between
               primitive impulse and intelligent action. Furthermore, its role in our epidemic of
               suicide and domestic violence has yet to be investigated.

               Humankind has barely ascended from the gene pool of thoughtlessness where
               reaction is the rule, and only by a slender thread does our humanity hang. This
               century, the human brain is being challenged by concentrations of lead and other
               heavy metals far beyond its evolutionary experience. The toxins we have loosed
               into the environment are corrosive to cognition and consciousness. By attacking the
               headquarters of our humanity, our priceless prefrontal cortex, they disintegrate our
               thin veneer of civilization shredding that slender thread.

                    "This, my dear Friend, is all I can at present recollect on the Subject.
                    You will see by it, that the Opinion of this mischievous Effort from
                    Lead is at least above Sixty Years old; and you will observe with
                    Concern how long a useful Truth may be known and exist, before it is
                    generally receiv'd and practis'd on.

                    I am, ever, yours most affectionately, B. Franklin"
 

               If he were here today, what would Benjamin Franklin say about the problem
               of lead contamination? Click here to read an imaginative "interview" with
               Dr. Franklin.
 
 
 

               References
               1. "Exposure of the U.S. Population to Lead, 1991-1994," Environmental
               Health Perspectives, Nov. 1998
               2. "Preventing lead poisoning in young children," Centers for Disease Control, Oct.
               1991
               3. "Measuring lead exposure in infants, children, and other sensitive populations,"
               National Research Council, 1993
               4. Walter J. Crinnion, N.D., Doctors Health Review, Aug. 1999
               5. Rachel's Environment & Health Weekly #633, Jan. 14, 1999
               6. Tuthill, R.W., "Hair lead levels related to children's classroom attention-deficit
               behavior," Arch Environ Health 1996 May-Jun;51(3):214-20
               7. Minder, B., et al.,"Exposure to lead and specific attentional problems in
               schoolchildren," J Learn Disabil 1994 Jun-Jul;27(6):393-9
               8. Brockel, B.J. & Cory-Slechta, D.A., "Lead, attention, and impulsive behavior:
               changes in a fixed-ratio waiting-for-reward paradigm," Pharmacol Biochem
               Behav 1998 Jun;60(2):545-52
               9. Reuters News Service, Feb. 11, 1999
               10. Bressler, J., et al., Neurochem Res 1999 Apr;24(4):595-600
               11. Zimmermann, H.P., et al., "Interaction of triethyl lead chloride with
               microtubules in vitro and in mammalian cells," Exp Cell Res 1985
               Jan;156(1):140-52, Faulstich, H., et al., "The molecular mechanism of interaction
               of Et3Pb+ with tubulin," FEBS Lett 1984 Aug 20;174(1):128-31, Konat, G.,
               "Triethyllead and cerebral development: an overview," Neurotoxicology 1984
               Fall;5(3):87-96
               12. Charles Gant, M.D., Ph.D., "Eat to Heal: New York Doctor Treats Attention
               Deficit Disorder (ADD) with Nutrition," Holistic Health Journal, Autumn 1997
               13. "Fluoride Banned in Thurmont, Maryland," Frederick Post, Feb. 3, 1994 and
               Letter from Water Quality Coordinator, Tacoma Public Utilities to Washington
               State Dept. of Health, Dec. 2, 1992 (Reported in Waste Not, Sept. 1998)
               14. "Pollution of the Caesars," Discover, March 1998
               15. "The Effects of Low Level Lead Exposure," Natural Resources Defense
               Council, 1978
               16. Rachel's Environment & Health Weekly #540, April 3, 1997
               17. "Lead Levels in Preindustrial Humans," New England Journal of Medicine,
               May 7, 1992
               18. USA Today, May 12, 1993


               Related Articles:

                 Moral behavior traced to specific brain area NEW YORK, Oct 19, 1999
 

                 Human genome could be mapped by June NEW YORK, Oct 14, 1999
                 (Reuters Health)
 

                 Marijuana-like substance in brain relieves pain NEW YORK, Oct 11, 1999
                 (Reuters Health)
 

                 Brain chemistry may explain addiction vulnerability NEW YORK, Sep 08, 1999
                 (Reuters Health)


A lead on why lead hurts the brain

                         Lead competes with calcium to bind to certain molecules in nerve cells, which may explain why the
                         metal damages the nervous system.

                         References:

                              Bouton, C.M.L.S., et al. 1999. Synaptotagmin is a molecular target for lead. Meeting of
                              the Society for Neuroscience. October. Miami Beach.

                         Sources:

                              Christopher M.L. Bouton
                              Johns Hopkins Medical Institutions
                              Department of Neurology
                              Department of Neuroscience
                              Baltimore, MD 21205

                         From Science News, Vol. 156, No. 19, November 6, 1999, p. 303. Copyright © 1999, Science Service.



 
 

                                                                                    s e a r c h

 <!--
 if (navigator.appName == "Netscape")
 document.write("<input type='text' name='NS-query' size=6 value='' maxlength='30' style='font-size:9pt'>")
 else
 document.write("<input type='text' name='NS-query' size=14 value='' maxlength='30' style='font-size:9pt'>")
 //-->
 
 

                                                                                World Series IQ
                                                                                Challenge

                                                                                Clinical Trials

                                                                                Health A-Z

                                                                                Merriam-Webster
                                                                               Medical-Dictionary

                                                                                Brain.com
                                                                                TestRunner
 

                                                                                  b r a i n   t o p i c s
 

                                                                                   d i s e a s e s   &   c o n d i t i o n s
 
 
 

              This information is not intended to be a substitute for professional medical advice. You should not use this information to diagnose or treat a health problem or disease without
 consulting with a qualified health care provider. Please consult your health care
  provider with any questions or concerns you may have regarding your condition.
 
 
 
 
 
 
 
 
 

                        copyright | privacy policy | acceptable use policy | online service agre
MAINPAGE