We're all exposed to different amounts of essential and toxic elements depending on where we live, our nutrition, environment and our lifestyle choices.
The levels of both essential and toxic elements that we consume, or that we are exposed to from the environment, are determined by where we live, the water we drink, the supplements we take, and the levels in soil/irrigation water used to grow the foods we eat. We are also exposed to toxic elements through environmental pollution of the air we breathe, as well as exposure through our skin.
How do different levels of essential and toxic elements aspect health? Essential elements are only conducive to optimal health when they are within optimal ranges. Levels that are too low or too high can have detrimental effects on health. Therefore, it is important to know if essential or toxic elements are outside their optimal ranges.
Both iodine and selenium are good examples of essential elements that can be both beneficial and toxic, depending on their levels. Severe iodine deficiency and extreme excesses cause thyroid deficiency and goiter. The same is true for selenium. A severe deficiency impairs the enzymes necessary for anti-oxidant actions and thyroid deiodinases that convert inert T4 to bioactive T3. In contrast, an excess of selenium can cause death.
Bromine is in the same chemical family as iodine and excessive amounts will compete with iodine in the thyroid. This becomes particularly problematic when iodine levels are borderline low, or lower, and bromine is high.
Copper and zinc are essential micronutrients that are needed in very small quantities in the diet but are toxic at concentrations greater than is necessary for their biological functions. Magnesium is an essential element with a significant role in cellular metabolism and protein synthesis, and its deficiency causes problems from muscle weakness to cardiac arrhythmias.
Arsenic, mercury, cadmium, and lead are toxic heavy metals with no known nutritional bene ts in the human body. High levels of them lead to an increase in Reactive Oxygen Species (ROS) that damage proteins, lipids, and DNA. They also form tight bonds with essential elements such as selenium, reducing its bioavailability for enzymes such as glutathione peroxidase and thyroid deiodinase, both essential for thyroid hormone synthesis and activation. Arsenic, mercury, lead, and cadmium are extremely hazardous to human health. They represent the top four most toxic heavy metals according to the CDC’s priority list of hazardous substances1. Lead, mercury, and cadmium accumulate and are retained in the body, and so their toxic effects are cumulative and more pronounced with ageing.
Very little lead is excreted in urine, but it is readily taken up by red blood cells where it forms a tight complex with haemoglobin. For this reason, whole blood, and not serum or urine, is used to monitor exposure to lead. Arsenic is only measured in urine and is not included in the blood spot proem because it is rapidly cleared from the bloodstream after exposure, and would therefore only be detected in blood if testing was done immediately after exposure.
In summary, testing for these elements provides an excellent assessment of overall body burden of toxic elements and is an indicator of excessive or inadequate supplementation with nutritionally essential elements.