Specifically, lead poisoning is often due to lead-based plumbing, lead-based paint (especially in older homes) and foods grown in lead-rich soil. Lead is also found in canned food, cigarette smoke (first- or second-hand), some ceramic dishes, refined chocolate and vehicle emissions. Lead has been linked to dementia, Alzheimer’s, learning disabilities, hyperactivity, seizures and aggression.
Mercury poisoning can occur from eating fish or shellfish contaminated with methylmercury. This includes king mackerel, bass, walleye, pickerel, shark and swordfish. The release of mercury vapor from dental amalgam fillings is another cause. Known for its speedy ability to cross the blood-brain barrier to affect the brain, mercury is linked to neurological, psychological, and immunological disorders in people, including diseases like Alzheimer’s. It has also been linked to heart arrhythmias, headaches, blurred vision, and weakness.
Cadmium poisoning has serious repercussions for the brain and inhibits the body’s ability to use nutrients like iron, zinc and calcium, leaving people more vulnerable to bone and immune system disorders. Cadmium is found in everyday household products such as electric batteries and floor coverings. It is can also be found in auto seat covers, black rubbers, ceramics, cigarettes, evaporated milk, fertilizers, fungicides, furniture, refined wheat flour, silver polish and soft drinks from vending machines with cadmium in the pipes.
Arsenic, now banned from production in the US since 1985, is still environmentally present naturally in ground water, mineral ore, geothermal processes and is released into the air by volcanos. Some seafood such as clams, oysters, crabs and lobsters, bottom-feeding finfish and seaweed/kelp may also contain arsenic. It is also present as an industrial byproduct related to burning fuel oils and coal, glass manufacturing and similar industries. Forms of arsenic are widely used in the electronics industry as components in semi-conductor devices. Arsenic poisoning is linked to kidney failure, vertigo, lung and skin cancers.
Aluminum, although technically not a heavy metal, can pose a health threat particularly with excessive exposure. Linked to Alzheimer’s and Parkinson’s diseases, aluminum is found in baby formula, baked goods and processed foods, deodorants, shampoos and skin creams, aluminum pots and pans, antacids and in many pharmaceutical drugs as a binding agent.
There are several common features among toxic heavy metals. Studies indicate that they cause oxidative damage due to direct generation of free radicals and depletion of antioxidant reserves. This proliferation of free radicals and oxidative stress leads to tissue acidification and inflammation, compromising the immune system. Many toxic metals can act as molecular “mimics” of nutritionally essential metals, competing with essential cofactors for entry into cells and enzymes. For example, cadmium can compete with and displace the essential nutrient zinc from proteins and enzymes.