INTRODUCTION
The Periodic Table of Elements lists all known elements. Elements are substances that cannot be decomposed to simpler substances nor formed by chemical union.
Carbon, hydrogen, oxygen, and nitrogen are the basic elements of life.
Nutritionally essential elements are those required to support adequate growth, reproduction and health throughout the life cycle when all other nutrients are optimal.
The macro essential mineral elements are those required in the range of grams per kilogram of diet. These are calcium, chloride, magnesium, phosphorus, potassium, and sodium.
The micro or trace essential elements are those required in the range of milligrams or micrograms per kilogram of diet. These are boron, chromium, cobalt, copper, fluorine, germanium, iodine, iron, lithium, manganese, molybdenum, selenium, strontium, sulfur, tin, vanadium, and zinc.
Toxic elements are those that have no role in human physiology, and may be harmful to human health when sufficiently present. These are toxic metals such as aluminum, cadmium, lead, mercury, and others. Some toxic non metals are thallium and uranium.
Essential elements can impact human health when they are either deficient or in excess.
Our general and personal environment can be responsible for introducing toxic elements to our body. The air we breathe, water we drink, and food we eat can contain toxic elements. Fossil fuel combustion, especially coal, contributes numerous toxic elements to air and water. Cadmium enters the environment from vehicular tire wear. Lead is still often present in highway paint. Mercury can enter our bodies from dental amalgams and fish, especially tuna. Cadmium and antimony can be present in cigarette paper to make it burn slowly.
The harmful effects of excessive essential and toxic elements is mostly due to free radical pathology. A free radical is any elemental species capable of independent existence that contains one or more unpaired electrons. Free radicals can be formed by the loss or gain of an electron by a non-radical. The oxygen molecule has two unpaired electrons and is a free radical. The transition metals (except zinc) contain unpaired electrons and can act as free radicals. These are chromium, cobalt, copper, iron, manganese, nickel, and vanadium. All toxic elements have free radical activity.
Free radical activity such as oxidation is part of normal human physiology which is controlled by antioxidants. Metal binding proteins can bind toxic metals and either excrete or store them in tissues. Excessive physiological stress, ionizing radiation (including sunlight), alcohol, excessive essential metals, and toxic metals can overwhelm our body’s natural defenses and allow free radicals to create uncontrolled damage. This damage can occur at the cellular, tissue, organ and system levels. Free radical damage can result in numerous diseases including cataracts, neuropathology, arthritis, atherosclerosis, and cancer. It plays a major role in the aging process.
Testing for essential element deficiency or excess can be done using blood or urine specimens. Iron is probably the most common essential metal in deficiency and/or excess. Iron deficiency causes anemia with decreased energy, fatigue, and pallor. Iron excess can cause fatigue, joint pain, heart failure, and cancer. In recent years, the upper level of ferriten (iron storage) has been lowered from previous levels due to the harmful effects of iron overload.
Toxic element exposure can be acute, chronic, or acute on chronic. Acute toxicity is best tested from blood. Many toxic elements will leave the blood and enter other tissues within two to three weeks following acute exposure. Increased levels of toxic elements in urine indicates that one’s body has exceeded it’s ability to store that element.
A challenge test is often used to determine the extent of tissue storage of toxic elements. Challenge testing is done by collecting a urine specimen, then EDTA 1.5gm IV over 3hours and /or DMSA 30gm orally is administered. After these chelating agent(s) is/are given, urine is collected for 6-8 hours. The pre challenge urine is compared to the post challenge urine for increases in toxic elements. If the toxic element is 2.5 times higher than the upper reference range of the pre challenge element this indicates excessive body storage of that element. Detoxification should be considered. Metals will be excreted in relation to both their concentration and affinity for the chelating agent.
Some researchers have stated that the most reliable methods of measuring body lead burden are bone x-ray fluorescence studies and EDTA mobilization tests. A person with a urine lead level of more than 2.9 micromoles/litre after intravenous infusion of 1gm EDTA is considered to have lead poisoning.
The toxic effects of even low lead levels in children, has been recently reported. Lead blood levels greater than 3.4 micromoles/litre can prove fatal. Those over 2.2 micromoles /liter may cause abdominal pain, constipation, anemia and encephalopathy. In 1991, the maximum allowable level was decreased from previous levels to 0.5micromoles/litre. More recent research has lead to the argument that the regulatory standard should be less than 0.1micromoles/litre.
Acute metal/element toxicity is more likely to be recognized and treated. We need to have much more recognition and treatment of chronic metal/element toxicity. If a person smokes cigarettes at one package per day, their total body burden of cadmium is exceeded in fifteen years. Cadmium is carcinogenic and causes vascular disease.
An important aspect of toxic metals is that they often have very long half lives. A half life is the time required for half of the amount of a metal to be removed from the body. This is especially important for cadmium and lead. These metals stay in the tissues for many years after exposure. Even after one quits smoking cigarettes, cadmium remains in the body for many years since it has a half life of about thirty years.
Treatment of essential mineral deficiency requires increased intake from food and/or supplements. Excessive essential minerals can be decreased by avoiding intake and/or removal. Blood donating and/or phlebotomy can decrease excessive iron.
Treatment of toxic metal accumulation begins by decreasing intake. Chelation therapy using oral and/or intravenous agents may be required.
Some toxic metals may augment the effects of other toxic metals when both are present together. Toxic metals may also decrease the absorption of essential minerals.
Essential minerals may also be in excess from over supplementation.
Research is required in several areas. The role of lithium in bipolar disease and iodine in thyroid disease is essentially unknown. The synergistic effect of toxic metal on metal activity requires more research. Research is also required in the area of toxic metals being passed through the placenta to a fetus: cadmium from a mother’s cigarette smoking and mercury from amalgams and/or diet may play a role in childhood autism. Finally, research is required as to whether cell phone use can lead to excitation and further damage from toxic metals in brain tissue.