Page 49 - Spring2018

adverse effects on the human metabolism. signaling molecules, which leads to induction of genes that contribute
A wide distribution of sulfhydryl (SH) to cell damage.
groups (organosulfur compounds) abounds in Brains of infants and animals exposed in utero show cell loss, reduced
the human body. Methylmercury has a high brain size, decreased protein production and changes in neurotransmis-
affinity for sulfhydryl groups of amino acids, sion resulting in cerebral palsy and mental retardation. 53
which are the building blocks for enzymes. As a Retention is around 95 percent of intake for methylmercury, 80 per-
pro-oxidant, mercury functions as a catalyst and cent for elemental mercury vapor, and 7 percent for inorganic mercury
oxidizes such groups. As with fluoride, mercury compounds. The toxicology of the three species of mercury intertwine
interferes with the formation and function of because organic mercury and elemental mercury convert to inorganic
many proteins and enzymes by combining with mercury in the brain. The dose in the brain from dental amalgams and
them. It also disrupts protein synthesis, which methylmercury may be cumulative. Inorganic mercury can remain in the
is potentially the major cause of neurotoxicity. brain for years. Daily excretion of methylmercury through the bile and
It also causes chromosomal breaks and DNA feces is about 1 percent of the body burden.
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damage. Mercury is a radiomimetic metal with Mercury depletes antioxidants such as selenium, which are needed
the same effects on the chromosomes and body for thyroid function, building selenoproteins and many other processes.
systems as radiation. Selenium depletion, as well as zinc depletion, influences neuronal func-
Methylmercury is readily absorbed into the tion and produces defects in neuronal plasticity, which can ultimately
GI tract after ingestion, and 90 percent can be affect behavior in children with attention-deficit/hyperactivity disorder. 54
found in red blood cells bound to hemoglobin.
Mercury in low concentrations in cellular PREVENTION
and animal experiments produces serious dis- In the past, children were major targets of mercury poisoning through
turbances in basal metabolic processes, disrupt- teething powders, laxatives, de-wormers, Mercurochrome, creams and
ing microtubules in the neuronal cytoskeleton. salves. Today they are exposed to mercury in vaccines and dental amal-
It binds to thiols in the tubulin and blocks the gams, in addition to mercury in the air, water, soil, food, medicines, paint,
electric activity in microtubules, which are cement, building materials, thermostats, thermometers, fungicides, light
required for many cellular functions, includ- bulbs and other sources at home and at school. Some traditional Chinese
ing division and migration. It also affects the and Hispanic remedies for stomach disorders contain mercury.
calcium balance in the microtubule. Parents should learn about sources of mercury and avoid bringing
The critical organ for methylmercury them into the home. Prevention and education are key to improving
toxicity is the brain. Mercury causes damage children’s health by reducing mercury exposure. By breastfeeding and
throughout the brain. The target organs for avoiding infant formulas, the infant will ingest a lower amount of many
elemental mercury are the brain and kidney. toxins, including mercury. If breastfeeding is not possible, homemade
It readily crosses the blood-brain barrier and infant formulas are a superior choice to any commercial formula. Babies,
firmly binds to molecules in the brain. There is toddlers and young children typically consume high amounts of cereals,
no innate mechanism for rapid removal. 50 teething biscuits and other items made from rice, which contain mercury
Astrocytes in the brain have a special role and other heavy metals. Traditionally, first foods for babies were liver
in early brain development and methylmercury and egg yolks. These continue to be outstanding sources of nutrients for
inhibits these functions. Methylmercury prefer- young children. Adolescents and young adults who use protein powders
entially accumulates in astrocytes, which make daily or even occasionally compromise their immune system and systemic
up about 50 percent of the CNS volume and health through ingestion of heavy metals. Consuming carbonated sodas
perform many important duties. They prevent and other beverages and foods containing HFCS adds further to the body
leaky blood-brain barrier, which limits the mercury burden. Children’s lunches and school events often feature food
transport of toxins into the brain and allows nu- items that contain rice, HFCS or high sugar content, artificial color and
trients to pass. Astrocyte dysfunction is a main flavorings, additives, maltodextrin and other sources of toxins.
cause of neurotoxicity. Methylmercury inhibits Pediatricians, nurses, dentists and other health care providers must
glutamate uptake in astrocytes. It promotes learn and understand the scope of mercury exposures and health problems
and enhances free radical formation, which is among children and be prepared to handle mercury exposures in medi-
known to play an important role in Alzheimer’s cal practice. Children, in contrast to adults, are the recipients of major
disease, Parkinson’s disease and amyotrophic sources of mercury through vaccines and dental amalgams. No “safe”
lateral sclerosis (ALS). It activates specific level can protect the most vulnerable from mercury’s toxic effects.

SPRING 2018 Wise Traditions 47