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TOXIC CAUSES
A small proportion of cases
have a toxic cause as the sole or a partial cause of Parkinson's Disease. The
toxic exposure usually has to be acute or chronic. Symptoms normally develop
when the toxic exposure occurs or soon after, or gradually increase over time
when the exposure persists. Symptoms do not develop years later as is sometimes
claimed. Avoidance of the source of toxicity can lead, in most cases, to a
reduction in the symptoms but with some toxins this can take years.
ANNONACEAE
Annonaceae is a family
of flowering plants that is also called the custard apple family. Some
annonaceae species produce edible fruits. Annonaceae contain acetogenins. In
Guadeloupe, Annonaceae are consumed as herbal teas and fruits, especially
soursop. Annonacin, which is the most abundant acetogenin, is toxic to
dopaminergic neurons in nanomolar concentrations. Acetogenins are potent
mitochondrial toxins, like other Parkinsonism inducing compounds. The
concentrations of annonacin, the major acetogenin in Annona Muricata, are so
high that one fruit or can of nectar per day is more in a year than induced
brain lesions in rats receiving purified annonacin by intravenous infusion.
CARBON DISULFIDE
Carbon disulfide is a colourless, flammable, and
poisonous liquid with the chemical formula CS2. Carbon disulfide is in
pesticides used as fumigants, disulfiram, which is a drug used in the
treatment of chronic alcoholism, industrial solvents, and solvents used in
the production of viscose rayon and cellophane film. Carbon disulfide interferes with the enzyme pyridoxal 5-phosphate, which is
essential for the formation of dopamine from L-dopa. So carbon disulfide
might cause Parkinson's Disease symptoms by reducing the formation of
L-dopa.
CARBON MONOXIDE
Carbon monoxide is a
colourless, odourless, and tasteless gas that is slightly less dense than
air. Carbon monoxide is produced from the
partial oxidation of carbon containing compounds when there is not enough
oxygen to produce carbon dioxide. Common sources are motor vehicle exhaust
fumes, and cigarette smoke. It also forms when fuels such as coal, paraffin,
oil or wood, and especially natural gas, do not burn completely in
appliances such as heaters, furnaces, stoves, water heaters, and ovens.
However, carbon
monoxide rarely causes Parkinson's Disease. It normally requires the person
having gone in to a coma as a result of the carbon monoxide poisoning before
symptoms of Parkinson's Disease develop.
COPPER
Copper, whose chemical
symbol is Cu, is a chemical element that is required as an essential nutrient, but
which can be toxic in large quantities. Common causes of copper toxicity
include Wilson's Disease in which there is a genetic accumulation of copper,
copper mines, copper cooking pots, copper plumbing, extreme consumption of
nutritional supplements that contain copper. Excessive copper can cause the
formation of a copper-dopamine complex, which leads to the oxidation of
dopamine to aminochrome.
CYANIDE
Cyanide is contained in drugs such as
potassium cyanide and sodium cyanide. Cyanides can also be produced by
certain bacteria, fungi, and algae, and are found in a number of foods and
plants. Cyanide occurs naturally in cassava roots (manioc).
Fruits that have a pit, such as cherries or apricots, often contain either
cyanides or cyanogenic glycosides in the pit. Bitter almonds, from which
almond oil and flavouring is made, also contain cyanide. Hydrogen cyanide is
contained in vehicle exhaust and in tobacco smoke. The smoke of burning
plastics contains hydrogen cyanide, and so house fires often result in
cyanide poisonings. Cyanides are one of the
very few soluble compounds of gold and thus are used in electroplating, gold
mining, metallurgy and jewellery for chemical gilding, buffing, and
extraction of gold. Cyanides and hydrogen cyanide are used in the production
of chemicals, photographic development, making plastics, fumigating ships,
and some mining processes. Potassium ferrocyanide is used to achieve a blue
colour on cast bronze sculptures.
CYCAD SEEDS
Cycad seeds of the Cycas micronesica contain ss-methylamino-L-alanine
(BMAA), which have been implicated as the cause of toxicity due to the involvement of a product of
BMAA and a beta-carbamate. Cycad seeds, by different means, can cause
Amyotrophic lateral sclerosis (ALS) and Parkinsonism-dementia complex (PDC).
This occurs in Guam, which is in the Mariana islands in the Pacific Ocean, the Kii peninsula of Japan, and New Guinea, which is
divided between Indonesia and Papua New Guinea.
DIELDRIN
Dieldrin is used as a pesticide. Dieldrin was the most frequently detected
Organochlorine pesticide in people with Parkinson's Disease thereby
suggesting that dieldrin may be associated with Parkinson's Disease.
Dieldrin levels were above normal in brains of people with Parkinson's
Disease. Dieldrin adversely affects cellular processes associated with
Parkinson's Disease including mitochondrial function and reactive oxygen
species production. Dieldrin showed inhibitory effects on proteasome
activities at low concentrations. Dieldrin induces apoptosis in dopaminergic
neurons via caspase-3-dependent proteolytic activation of protein kinase C
delta.
HYDROCARBONS
Hydrocarbons are organic compounds consisting entirely of hydrogen and
carbon. Common sources are : hydrocarbon
poisoning such as that of benzene and petroleum usually occurs accidentally
by their inhalation or ingestion. Sources of hydrocarbons include : natural
gas, cooking gas, petrol, gasoline. People that have been subjected to exposure
to petroleum products, especially when working with petroleum products,
increase the likelihood of developing Parkinson's Disease.
Working in a gas station (petrol station) increased the risk of Parkinson's
Disease by 2.6 times.
LEAD
Lead is a chemical element that is
toxic in humans. Common sources are : lead contaminated soil, ingestion of lead
dust or chips from deteriorating lead-based paints, air pollution from the
processing of lead, food grown in contaminated soil, drinking water from
plumbing and fixtures that are either made of lead or have trace amounts of
lead in them. Lead can also be found in cosmetics in some countries, some
herbal remedies, and in toys such as many from China. Serious and chronic
exposure to lead can more than double the likelihood of developing
Parkinson's Disease. Milder exposure to lead did not increase the likelihood
of Parkinson's Disease.
MANEB
The main active element of Maneb is manganese
ethylene-bis-dithiocarbamate. Maneb is used as a fungicide. There is a
greatly increased likelihood of developing symptoms by people involved in
horticulture and agriculture. As Maneb contains manganese it is possible
that it causes Parkinson's Disease symptoms via the same means as manganese,
which is by inhibiting tyrosine hydroxylation. Tyrosine hydroxylation is
essential for the formation of dopamine. It would thereby lower dopamine
levels. The effects of Maneb are potentiated when there is simultaneous
exposure to the pesticide Paraquat.
MANGANESE
Manganese is a chemical element
that is required as a nutrient but can be toxic in large quantities. Occupational exposures occur in welding, when highly
exposed, miining as miners are surrounded
by manganese dust and airborne manganese particles, alloy production,
processing, ferro-manganese operations especially in which manganese ore or
manganese compounds are turned into steel, and work with agrochemicals.
Areas surrounding manganese heavy industry
could also become affected by exposure to manganese. It could occur with
very excessive use of manganese supplements. Manganese can cause Manganism,
which is a medical disorder that is virtually no different in its symptoms
from Parkinson's Disease.
MERCURY
Mercury is a chemical element that is toxic in humans.
Common sources are : dietary fish intake, ethnic over-the-counter
medications, occupational exposures to mercury vapour, possession of dental
amalgam fillings, gold production, skin ointment, and some soaps. One of the
chief means of toxicity is via the enzyme pyruvate dehydrogenase (PDH),
which is irreversibly inhibited by several mercury compounds. However, the
cause of the symptoms of Parkinson's Disease is likely to be due to the fact
that mercury potently causes the release of dopamine, thereby lowering
dopamine levels.
MPTP
MPTP (1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine) is a
chemical that may be produced accidentally during illicit manufacture of the
recreational drug MPPP, which is a synthetic heroin substitute. The most common source
is the recreational drug MPPP
(Desmethylprodine). It was also developed but unused as a herbicide. It is
also an industrial toxin. MPTP inhibits tyrosine
hydroxylation, which is essential for the formation of dopamine. So MPTP
causes Parkinson's Disease by lowering dopamine levels.
N-HEXANE
N-Hexane is an alkane. Most of the n-hexane used
in industry is mixed with solvents. The major use for solvents containing
n-hexane is to extract vegetable oils from crops such as soybeans. These
solvents are also used as cleaning agents in the printing, textile,
furniture, and shoemaking industries. It is also used by chemists. Certain glues used in
the roofing and shoe and leather industries also contain n-hexane. Several
consumer products contain n-hexane, such as gasoline, spot removers,
quick-drying glues used in various hobbies, and rubber cement.
NITROGEN DIOXIDE
Nitrogen dioxide is an intermediate in the
industrial synthesis of nitric acid, millions of tons of which are produced
each year. At higher temperatures it is a reddish-brown gas that has a
characteristic sharp, biting odour and is a prominent air pollutant. Exposure of nitrogen dioxide to tyrosine hydroxylase results
in the nitration of its tyrosine residues. High exposure to
nitrogen dioxide, largely because of pollution, trebled the risk of
Parkinson's Disease. Lower exposures did not significantly increase the
risk.
OCTENOL
Octenol, which is commonly known as mushroom alcohol, is produced by
several plants and fungi. Octenol can often be inhaled by humans after being produced in
damp, mouldy or water damaged buildings. Octenol
interferes with two genes involved in the creation of dopamine : the human
plasma membrane dopamine transporter (DAT) and the human VMAT ortholog
(VMAT2). This demonstrates that 1-octen-3-ol exerts toxicity via disruption
of dopamine homeostasis.
ORGANOPHOSPHOROUS PESTICIDES
Organophosphorous pesticides are used primarily in pest control as
alternatives to chlorinated hydrocarbons that can persist in the
environment. Organophosphorous pesticides are used in agriculture.
Organophosphorus chemicals have also been used as active ingredients in
household pesticides for several decades. Organophosphorus pesticides are
significantly associated with Parkinson's Disease. The frequent use of
household pesticides that contain organophosphorus chemicals increased the
chances of developing Parkinson's Disease by 71% .
PARAQUAT
Paraquat is used as a herbicide. There is a
greatly increased likelihood of developing symptoms by people involved in
horticulture and agriculture. People with Parkinson's Disease are more
than twice as likely to report heavy exposure to pesticides over their
lifetime as family members without Parkinson's Disease. Those people
affected were usually those who used a lot of pesticides in their homes and
in their hobbies rather than those who routinely used pesticides for their
occupation. Pesticides are also known to affect well water. However, it is
claimed that Paraquat only potentiates the effect of Maneb, and
that it has no effect on humans on its own.
ROTENONE
Rotenone is used as an insecticide. There is a
greatly increased likelihood of developing symptoms by people involved in
horticulture and agriculture. People with Parkinson's Disease are more
than twice as likely to report heavy exposure to pesticides over their
lifetime as family members without Parkinson's Disease. Those affected were
usually those who used a lot of pesticides in their homes, rather than those who routinely used pesticides for their
occupation. Insecticides are also known to affect well water. Rotenone is
commonly used to treat parasitic mites on chickens and other fowl, and so
can be found in poultry. Rotenone inhibits tyrosine hydroxylation, which is
essential for the formation of dopamine.
TOLUENE
Toluene is
used as an octane booster in fuel, as a solvent in paints, paint thinners,
chemical reactions, rubber, printing, adhesives, lacquers, leather tanning,
disinfectants, producing phenol and TNT. Toluene is also used as a raw
material for toluene diisocyanate, which is used in the manufacture of
polyurethane foams. Toluene is also used in the manufacture of dyes. Dyes
are highly associated with the symptoms of Parkinson's Disease. The means of toxicity is unknown. Toluene has been shown to cause
Parkinson's Disease or has been associated with people with Parkinson's
Disease.
TRICHLOROETHYLENE
Trichloroethylene is a solvent with a sweet smell that is a clear
non-flammable liquid. Trichloroethylene is a solvent that is used in
industry and the military and is a common environmental contaminant. It has
been used to extract vegetable oils, in coffee decaffeination, and the
preparation of flavouring extracts from hops and spices. The means of toxicity is unknown. Workers with workstations adjacent to the
source of trichloroethylene and who were subjected to chronic inhalation and
dermal exposure from handling trichloroethylene-soaked metal parts all had
Parkinson's Disease.
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THE
COMPREHENSIVE GUIDE TO PARKINSON'S DISEASE
Keith Bridgeman, Tahira Arsham
The Comprehensive
Guide to Parkinson's Disease, which is fully referenced, and nearly
800 pages long, is the most comprehensive book concerning
Parkinson's Disease ever written. It includes its history, famous
people with Parkinson's Disease, its complete biochemisty, cytology
and cytological effects, anatomy and anatomical effects, physiology
and physiological effects, symptoms (of every system in the body),
diagnosis methods (observational, technological, chemical),
biochemical causes, toxic causes, genetic causes, pharmacological
causes, medical causes, treatments (biochemical, pharmacological,
surgical, natural, exercise methods, technological methods),
organisations, web sites.
CLICK HERE FOR MORE DETAILS |
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