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By
Linda G. Shepard
In the search for pieces to the autism puzzle, a growing
number of people in the autism community have turned their
attention to the possible role of heavy metals. Some symptoms
and behaviors observed in Autism Spectrum Disorders appear
to parallel those seen in heavy metal toxicity. Tests for
one metal often reveal high levels of other metals as well.
A reduction in the body burden of heavy metals has coincided
for some in a reduction of behaviors associated with ASD.
As the rise in incidence of autism and the possibility of
a link between the mercury content of vaccines and autism
has reached the mainstream media, the autism community has
become a target market of it's own. As consumers, we must
educate ourselves and weigh the potential benefits of various
treatments and products carefully.
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Symptoms of Heavy Metal Toxicity
The diversity of ways in which metal toxicity
manifests itself makes it difficult to recognize by
observation alone. Toxic metals may interfere with the
normal function of any system of the body.
Common symptoms of aluminum toxicity include memory
loss, jerking movements, and impaired coordination.
A quick glance at the long list of symptoms of mercury
poisoning reveals the following: anxiety, sensitivity
to touch, burning sensation, candidiasis, cold hands
and feet, confusion, dark circles under eyes ("allergic
shiners"), depression, disorientation, dexterity
problems, ear congestion, easy to anger, eating problems,
emotional problems, exaggerated response to stimuli,
eye problems, facial twitch, fearfulness, feelings of
desperation and panic, gastrointestinal problems, hearing
problems, inability to accept criticism, irritability,
irrational or erratic behavior, lack of coordination,
and numbness in extremities among others.
Lead poisoning symptoms include loss of appetite, apathy,
irritability, refusal to play, constipation, decreased
intelligence, hyperactivity, aggression, poor impulse
control, poor eye-hand coordination, and impaired motor
skill development.
Most lists of metal toxicity symptoms include references
to behaviors which parallel those seen in Autism Spectrum
Disorders. If one suspects metal toxicity, a hair analysis
provides a non-invasive, relatively inexpensive way
to access a wealth of information.
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Filtering out environmental toxins appears to be more of
a challenge for individuals with Autism Spectrum Disorders
than it does for the general population. A combination of
factors may play a role: compromised immune systems, compromised
detoxification pathways, multi-generational bioaccumulation
of toxins, high exposure, exposure at critical points in development,
and impairment of the mechanisms for dealing with toxins.
We cannot avoid environmental toxins entirely, as we come
in contact with many substances throughout our normal daily
activities. However, we can increase our awareness of toxins,
their known effects on humans, the sources and routes of exposure,
and reduce or eliminate exposure as much as possible.
This article will focus primarily on common metals to which
we are routinely exposed. We come in contact with these metals
through inhalation, ingestion, absorption, and in some cases
injection or implantation. Exposure may occur with or without
our knowledge, through air, water, food, or consumer products.
While obvious symptoms may occur as a result of acute exposure,
chronic exposure is more challenging to recognize, more likely
to go undetected, and more difficult to trace to a particular
cause or exposure.
Toxic Metals
“Toxic metals are all those whose concentrations in
the environment are now considered to be harmful, at least
to some people in some places.” (1) People come in contact
with aluminum, antimony, arsenic, cadmium, lead, mercury,
nickel, and tin on a regular basis. Unfortunately, medical
personnel may not recognize acute metal toxicity, let alone
chronic toxicity, so individuals who suspect some level of
toxicity must educate themselves. What if you do suspect toxicity?
What can you do? First try to identify the source, then try
to eliminate or reduce it, taking precautions to avoid further
exposure. In some cases, removal of the source allows the
body to detoxify and heal itself. In other cases, the body
needs assistance through chelation, nutritional support, or
other means. Luckily, if an individual has high levels of
several metals, ridding the body of one may allow the body
to release the others.
How do you find the source? Start with a thorough examination
of the house, day care center, school, or other buildings
where the individual spends a significant amount of time.
Consider having soil and tap water tested. Many people choose
to use reverse osmosis water or use a filtration system to
reduce potential toxins from their water supply. Remember,
also, that the body absorbs some toxins through the skin or
inhales them from steam from a bath or shower. Consider the
food you eat and the products you use, and don’t overlook
all the stages through which they pass before you get them.
The higher up on the food chain a food is, the more likely
it accumulates toxins from whatever it eats.
Take into account toxins encountered in the workplaces or
through hobbies. When available, use non-toxic alternatives.
A recent book explores the widespread practice of recycling
toxic waste containing cadmium, arsenic, lead, nickel, and
mercury as fertilizer. (2) If you use items which contain
toxins, find out ahead of time how to handle a spill or breakage
should it occur. For example, if you break a fluorescent light,
do not vacuum the fragments as that further disperses the
mercury.
When buying products consider what went into its processing,
packaging, transportation and what will happen to it when
you no longer need or want it. Metals may change form but
they don’t go away. Products you use today that contain
toxins may affect many different people once you discard them.
Common heavy metals that can be toxic to individuals with
autism/AS are listed below.
Aluminum
Symbol: Al
Although not a heavy metal, aluminum appears to pose some
health concerns. “Aluminum is the third most abundant
element in the earth’s crust and the most abundant metal.”
(3) It is used for some cans, cookware, aluminum foil, in
buffered aspirin and some antacids, some vaccines, and most
baking powder. Processed cheese often contains aluminum and
manufacturers add it to salt, non-dairy creamers, and dry
powdered products as an anti-caking agent. Exposure to aluminum
may also occur through the use of some products for treating
diarrhea, hemorrhoid medications, vaginal douches, antiperspirants,
and lipsticks. Water districts add aluminum to water during
the fluoridation process.
Studies have shown an increased amount of aluminum in the
brains of individuals with Alzheimer’s Disease, although
they don’t conclude what causes the increase. Aluminum
dust can cause lung disease in workers, and patients undergoing
kidney dialysis have suffered dementia from aluminum toxicity
if ordinary tap water was used in the dialysis machine. (4)
Industrial exposure to the dust which occurs in aluminum manufacturing,
and the production of fireworks and explosives can result
in a lung disease called pulmonary fibrosis.
The EPA has established criteria for allowable levels of
aluminum in waterways for the protection of aquatic life but
does not regulate levels in the air or our drinking water.
Areas with acid rain have increased levels of aluminum in
surface water and have had fish die-offs as a result. The
acid rain dissolves the aluminum from the soil and rocks.
Antimony
Symbol: Sb
Antimony is used as a flame retardant on sleepwear and bedding,
as medicine for people with parasites, in paint, ceramics,
fireworks, and in alloys in lead storage batteries, artillery
shells, solder, sheet and pipe metal, bearings, castings,
pewter, type metal and anti-friction machines. (5) Graco recently
recalled several products because of their antimony and arsenic
content.
Antimony may also enter the air, soil, and water as a by-product
from the smelting of lead and other metals. Breathing high
levels can result in coronary and pulmonary problems, stomach
pain, diarrhea, vomiting, and stomach ulcers. Animal studies
have demonstrated fertility problems and death. (6)
Some research suggests antimony plays a role in Sudden Infant
Death Syndrome (SIDS). (7) The “Back to Sleep” program
encouraging parents and caregivers to place infants on their
back to sleep appears to reduce the incidence of SIDS by moving
the child’s nose and mouth farther from the antimony fumes.
Arsenic
Symbol: As
Pesticides containing arsenic often get sprayed on golf courses
and orchards. Wood preservatives contain arsenic in the form
of copper arsenate. Many people have used this lumber for
playground equipment.
Arsenic enters the environment primarily from air pollution
and by seeping into the soil and ground water from hazardous
waste dumps. Most medical use of arsenic for humans has ceased
but its use in veterinary medicine continues. Poultry and
swine producers add arsenic to animal feed as a growth enhancer,
discontinuing the additive a few days before slaughter, presumably
to allow for the excretion of the residues. Antibiotics given
to commercial livestock and pesticide residues contribute
to human exposure. Tobacco leaves contain arsenic. Coal burning,
metal ore smelting, and the production and use of pesticides
introduce arsenic into the environment.
A re-assessment by the Academy of Science requested by the
current administration has confirmed the need for a reduction
in the acceptable level of arsenic in our nation’s drinking
water.
Cadmium
Symbol: Cd
The EPA listed this element as a hazardous air pollutant in
the 1990 Clean Air Act and by December 1990 had set the standard
for maximum allowable cadmium levels in drinking water at
5 micrograms per liter. Cadmium has the following uses: to
galvanize metal parts, as a pigment in paints and plastics,
in rechargeable nickel-cadmium (ni-cad) batteries, and as
a catalyst and preservative in the plastics industry. Some
alloys, solders, and the pigments in ceramic glazes, oil paints,
and other arts supplies may contain cadmium. Tobacco smoke
contains cadmium. Processes which release cadmium into the
atmosphere include the burning of coal and other fossil fuels,
sewage sludge, medical, and municipal waste. Cadmium contamination
of the soil, water, and sediments can occur through municipal
wastewater treatment, electroplating, metal processing, plastic
and dye manufacturing, and the application of phosphate fertilizers.
Cadmium enters plants and animals from the soil and water
thus entering the food supply. Currently, food contributes
80-90% of the cadmium dose received by most people. (8)
The EPA classifies cadmium as a probable human carcinogen.
Chronic exposure to cadmium is also associated with a wide
range of other diseases, including heart disease, anemia,
skeletal weakening, depressed immune system response, and
kidney and liver disease. (9)
Lead
Symbol: Pb
Lead can cause severe health effects at relatively low levels
of exposure. For this reason, regulations established years
ago have resulted in decreased lead concentrations in the
environment. Current primary uses of lead in the United States
include storage batteries, ammunition, and solder. Tap water
may leach lead from pipes and solder. A University of Michigan
School of Public Health study found candles with lead core
wicks that release lead into the air when burned. Children
may have exposure to lead from old paint chips, soil, and
dust. Due to the sweet taste of lead dust this poses a particular
hazard for individuals with pica. Foods absorb lead from the
soil and water. Antique pewter and some ceramic glazes contain
lead. Mining, smelting, and manufacturing facilities release
lead into the environment.
Lead affects the human nervous system, the production of
blood cells, kidneys, the reproductive system, and behavior.
Lead passes the placenta and can damage the fetal nervous
system, increasing the risk for premature birth or low birth
weight and size babies, or it can induce miscarriage. Nutritional
deficiencies increase the risk for lead absorption and toxicity.
Lead typically remains in the blood for a relatively short
time then settles in the bones and teeth taking the place
of calcium. Blood lead levels which require action have decreased
from 60 micrograms per deciliter, set in the mid-1960s, to
10 micrograms per deciliter, as of October 1997. (10)
Before treating for lead poisoning, the individual must be
removed from the source of the lead. If this requires removing
lead paint educate yourself thoroughly on how to do this without
additional exposure or have someone trained in the field do
the work. European nations had bans on lead in place by 1930.
However, in the U.S. it wasn’t until 1971 that Congress
passed the Lead-Based Poisoning Prevention Act and until 1977
that it was put into place.
The EPA has established air quality standards and drinking
water levels for lead for the protection of humans. The Consumer
Protection Safety Commission has banned toys, children’s
items and furniture that have paint with a lead content greater
than 0.06%. The Physician’s Desk Reference recognizes
lead poisoning and recommends chelation with oral DMSA (Dimercaptosuccinic
Acid) to bind the lead for excretion in the urine.
Studies have shown a decrease in ability to learn among individuals
with high levels of lead. A study by Deborah Denno of Fordham
University in New York City noted a strong connection between
lead poisoning and crime among males she studied from birth
to age 24.
Mercury
Symbol: Hg
Mercury, a heavy, silver-white, highly toxic metallic element,
is the only one that is liquid at room temperature. As quicksilver
it is used in barometers, thermometers, pesticides, pharmaceutical
preparations, reflecting surfaces of mirrors, and dental fillings,
in certain switches, lamps, and other electric apparatus,
and as a laboratory catalyst. (11) Hawley’s Condensed
Chemical Dictionary described mercury as: “Hazard: 1.
Mercury, metallic: Highly toxic by skin absorption and inhalation
of fume or vapor, absorbed by respiratory and intestinal tract...2.
all inorganic compounds of mercury are highly toxic by ingestion,
inhalation, and skin absorption... inorganic mercury can be
converted to methyl-mercury by bacteria in water...”
(12)
One of the biggest exposures to mercury comes from the use
of mercury amalgam dental fillings, often referred to as “silver”
fillings. These provide an on-going source of exposure 24
hours a day, 365 days a year and can be highly toxic. “Most
people with amalgam fillings get an unsafe dose of the heavy
metal because mercury vapor leaks continually from the fillings.”
(13) “Every one of these (published human autopsy) studies
showed that the amount of mercury found in the brain tissue
or kidney tissue was directly related to the amount of mercury
amalgam filling material found in the teeth.” (14) Studies
by the World Health Organization show that a single amalgam
can release 3-17 mcg of mercury per day. In 1998 the Environmental
Protection Agency declared scrap (dental) amalgam a hazardous
waste. OSHA has classified dental amalgam as a hazardous waste.
Mercury amalgam, a toxic substance before it goes into our
mouths and hazardous waste when it comes out, is yet touted
by the American Dental Association as perfectly safe while
in your mouth or the mouth of your child.
Many of us have also had mercury injected into us as an ingredient
in the preservative thimerosal used in vaccines. On July 9,
1999, the US Public Health Service and the American Academy
of Pediatrics issued a joint statement recommending the removal
of thimerosal (a preservative containing mercury) from vaccines.
The Food and Drug Administration concluded that some infants
were being exposed to cumulative amounts of ethyl-mercury
and instructed manufacturers to remove thimerosal. The Center
for Disease Control’s Advisory Committee on Immunization
Practices urged manufacturers to remove mercury from their
vaccines “as rapidly as possible”. The Institute
of Medicine (IOM) recommended that vaccines containing thimerosal
be removed from use.
“Mercury poisoning and autism have nearly identical
symptoms: self-injurious behavior, social withdrawal, lack
of eye contact, lack of facial expression, hypersensitivity
to noise and touch, and repetitive behaviors.” (15)
“Neurotoxicity is the health effect of greatest concern
with mercury exposure. Ingested methyl-mercury is almost completely
absorbed into the blood and distributed to all tissues (including
the brain), it also readily passes through the placenta to
the fetus and fetal brain. The developing fetus is considered
the most sensitive to the effects of mercury.” (16)
Dangers of mercury have come to the public’s attention
numerous times throughout history. So many in fact, that mercury
poisoning has a variety of other names related to the various
incidences. These include “Pink Disease” from
teething powder, “Madder Hatter’s Disease”
or “Danbury Shakes” which occurred when hat makers
dipped the felt or fur into vats of mercury, and “Minamata
Disease” when Japanese ate fish contaminated by industrial
waste dumped in Minamata Bay. Individuals also got poisoned
from eating pigs fed grain treated with mercury. “The
brain succumbs to mercury’s ravages more readily than
other tissues. Borne by the bloodstream, methyl-mercury penetrates
brain membranes that bar most other poisons. First it damages
the organ without appreciable loss of cells, then erodes whole
pockets of tissue. Worst hit are the brain’s visual,
hearing, and equilibrium centers, thus explaining the effects
of mercury poisoning—blindness, deafness, and loss of
balance.” (17)
“Mercury is a persistent, bioaccumulative, and toxic
(PBT) pollutant.” (18) The Association of Metropolitan
Sewerage Agencies (AMSA) reports that mercury levels in household
wastewater are sufficiently high to pose Clean Water Act compliance
problems for the nation’s wastewater treatment plants.
Although several sources contributing to the domestic mercury
concentration have been identified, human wastes from individuals
with dental amalgam fillings are believed to be the most significant
source-—greater than 80 percent.
While medical personnel continue to administer doses of mercury
to humans using various routes, veterinarians receive the
following cautionary information. “The organic mercurials
are absorbed via all routes and bioaccumulate in the brain
and to some extent in the kidneys and muscles...Mercury is
also a mutagen, teratogen, and a carcinogen, and is embryocidal.”
(19) Other fields recognize the dangers and work to reduce
the use of this toxin. Advisories in the United States have
been issued by 39 states and some Tribes, warning against
consumption of certain species of fish contaminated with methyl-mercury.
Indiana, Maine, Maryland, Minnesota, Oregon, and Rhode Island
have passed laws banning the sale of mercury thermometers
and a variety of other uses of mercury. “The American
Academy of Pediatrics has advised doctors and parents to stop
using mercury thermometers because of the toxicity of mercury
vapor to both humans and wildlife...To get rid of your unbroken
thermometers or fluorescent lamps, don’t just throw
them away. Take them to a hazardous-waste collection center.”
(20)
If you suspect mercury toxicity remember that blood and urine
tests show only recent exposure and even hair analysis doesn’t
usually show high mercury. Rather mercury interferes with
the transport of minerals so a hair analysis will show a significant
scatter among the essential elements. A number of individuals
getting tests or treatment for themselves or their children
have found insurance much more willing to pay when using the
code for metal toxicity rather than mercury toxicity or autism.
Do not attempt mercury detoxification if you still have mercury
amalgam dental fillings. Doing so may make matters worse.
If you choose to have your fillings replaced, thoroughly educate
yourself first and find a dentist who has a mercury-free practice,
uses the proper protocol, and has experience with the replacement
materials. The dentist should work with you to minimize any
further exposure and make sure you end up with biocompatible
replacements.
A number of individuals have experienced increased excretion
of the mercury stored in their tissues through the use of
chelation. Opinions vary as to the most appropriate dosing
level and schedule. Most use DMSA and/or Alpha Lipoic Acid
(ALA).
Nickel
Symbol: Ni
Nickel is widely used in consumer products including buttons,
zippers, coins, dental braces, orthodontic appliances, household
appliances, tools, artificial joints, jewelry, faucets, batteries,
hairspray, cold-wave permanent solutions, shampoos, paint,
spray paint, varnish, pipes, and many products made of stainless
steel. Nickel occurs naturally in some foods and manufacturers
use it in the hydrogenation process. Nickel exposure also
occurs from both first and second-hand tobacco smoke. The
Food and Drug Administration (FDA) considers nickel safe as
a direct human food ingredient. Nickel contact dermatitis
affects an estimated 2.5 to 5% of the population, with women
more affected than men. A family sensitivity to nickel raises
one’s risk factor.
Cancers of the lung, nasal passage, and possibly the larynx
may occur from occupational exposure. Metal refineries and
municipal solid waste incinerators release nickel into the
air, soil, and water. The U.S. has not had any active nickel-producers
since 1985 but soil from or near the former sites may continue
to pose a source of exposure. Nickel accumulates in aquatic
food chains with freshwater organisms more sensitive than
ones from saltwater. The 1990 Clean Air Act lists nickel as
a hazardous air pollutant. (21)
Tin
Symbol: Sn
Some individuals with ASD show elevated levels of tin. Stannous
fluoride used in toothpaste contains tin. Manufacturers in
the US use aluminum or steel for cans, but some imported items
come in tin cans. Tin-based products in paint used to protect
the hulls of ships and boats from various marine organisms
appears to harm fish and shellfish even at low levels and
therefore Congress approved a bill in 1988 which limits the
use of these products. (22)
The possible connection between autism and environmental
toxins is a question that will not be resolved anytime in
the near future. Therefore, it becomes the onus of all parents
of children and adults with autism to become educated on the
various toxic metals that are part of our daily existence,
and the symptoms they manifest. Only through expanded awareness
can we best limit exposure and protect our children and ourselves
from future harm.
References:
1. Duff Wilson , (2001). Fateful Harvest.
2. John Harte, Cheryl Holdren, Richard Schneider, Christine
Shirley, (1991). Toxics A to Z: A Guide to Everyday Pollution
Hazards.
3. ibid.
4. ibid.
5. British Columbia Institute of Technology Chemistry Resource
Center
6. John Harte, Cheryl Holdren, Richard Schneider, Christine
Shirley, (1991). Toxics A to Z: A Guide to Everyday Pollution
Hazards.
7. Agency for Toxic Substances & Disease Registry (ATSDR),
1992
8. www.criblife2000.com
9. John Harte, Cheryl Holdren, Richard Schneider, Christine
Shirley, (1991). Toxics A to Z: A Guide to Everyday Pollution
Hazards.
10. Random House Dictionary of the English Language,
1987 (italics added)
11. Richard M. Stapleton, (1994). Lead is a Silent Hazard.
12. Revised by N. Irving Sax and Richard J. Lewis, Sr. (1987).
Hawley’s Condensed Chemical Dictionary, Eleventh
Edition (italics added)
13. Boyd Haley, Chair of Chemistry, University of Kentucky,
testifying before Congress
14. Sam Ziff, editor & publisher, “Dental and Health
Facts”, Foundation for Toxic-Free Dentistry
15. Stephanie Cave, M.D., “What About Mercury?”
Mothering Magazine, March/April 2001 (author of What
Your Doctor May Not Have Told You About Children’s Vaccines,
2001)
16. EPA Mercury White Paper
17. John J. Putnam, (October 1972). “Quicksilver and
Slow Death”, National Geographic.
18. Environmental Protection Agency
19. Parade Magazine, September 16, 2001
20. The Merck Veterinary Manual, 8th Edition, 1998
21. John Harte, Cheryl Holdren, Richard Schneider, Christine
Shirley, (1991). Toxics A to Z: A Guide to Everyday Pollution
Hazards.
22. ibid.
Linda G. Shepard has worked with children and adults
with developmental, physical, cognitive, and behavioral challenges
including individuals with Autism Spectrum Disorders. Her
experience ranges from assessing infants and toddlers to assisting
adults with life skills education. Linda survived mercury
poisoning from her dental fillings. She participates on the
Mercury Awareness Team and the Autism-Mercury e-group. Her
oldest nephew has a diagnosis of autism. Contact Linda at:
L_Shepard@mymailstation.com
Reprinted with permission from the May-June 2002 issue of
the Autism Asperger’s Digest, a 52 page bimonthly magazine
devoted to autism. www.autismdigest.com
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