What Is a Heavy Metal?
Even experts disagree on the definition of a heavy metal. Chemists have used density, atomic weight, atomic number and periodic table position to define heavy metals. Part of the problem is that not all heavy metals are toxic. Some, like iron, are essential for human life. Although a definition is elusive, experts do agree on the heavy metals that are highly toxic. Among them are: lead, mercury, cadmium, aluminum, and arsenic. These metals build up in the body over time, so the initial symptoms are often subtle. At high levels, the metals cause irreversible damage or death.
Lead is a ubiquitous and widely-known toxic metal. The dangers of lead poisoning were recognized in the days of Julius Caesar, yet the World Heath Organization estimated that 143,000 people died of lead poisoning in 2013. Why is lead still a problem when it was eliminated from paint and gasoline decades ago? The reality is that lead is still around in surprising places: solder joints in plumbing, glass (re-think Grandma’s crystal) and batteries. Because lead interferes with the development of the nervous system, it is particularly dangerous to children where it can cause permanent mental and physical impairment. If you have children and suspect lead in your home environment, lead test kits are widely available and reasonably accurate.
Although mercury is present in thermometers, thermostats, fluorescent and mercury vapor lights as well as some cosmetics, the primary sources of mercury poisoning are dental amalgams, vaccines, and contaminated fish. To reduce the risk of food ingestion, limit fish consumption (especially tuna), find a source that is tested, or use fish oil supplements. Limiting exposure from dental fillings and vaccines is trickier. There are substitutes, so it is worth discussing with your healthcare provider.
Aluminum is the most abundant metal in the earth’s crust. Because it occurs naturally in food and water, daily exposure is inevitable. Elevated levels of aluminum in the brains of some Alzheimer’s patients have led researchers to question if it plays any role in the development of the disease. Besides water, researchers have pointed to antiperspirants containing aluminum as a possible source of contamination. If you are concerned about exposure, try looking for a brand without aluminum. You may also want to avoid aluminum cookware and foil as well.
Like aluminum, cadmium occurs naturally in food and water. It is a particularly nasty carcinogen because it directly disturbs DNA as well as DNA repair and is not easily released from the body. Therefore, it continues to accumulate in the body. Because of its toxicity, cadmium levels are strictly limited in workplace environments. The biggest risk for exposure outside the workplace is tobacco smoke. If you haven’t already quit smoking, this is a good reason to stop.
Arsenic is used primarily in pesticides and as a wood preservative in treated lumber (your old deck is not firewood). Once released arsenic cannot be destroyed, so it often finds its way into the good water. Since arsenic is a potent carcinogen, it is a good idea to test wells frequently to assure levels are below the EPA standard.
How To Protect Yourself
The best protection against heavy metal toxins is to limit contact with sources of contamination. However, several dietary nutrients have been found to mitigate heavy metal damage by inhibiting absorption, reducing free-radical damage or binding with metals so they can be naturally excreted. Among the beneficial nutrients are vitamin C, vitamin E, folate, garlic, cilantro, probiotic bacteria and chlorella (green algae used to detoxify wastewater). Mother was right. . .drink your orange juice!