The Health Effects of Metals
Think about the last glass of water you drank. It likely contained various minerals, natural or added, that supplement the adequate nutrition of your body. While some metals are essential for nutrition and regular bodily function, too much exposure to certain metals can have serious health effects.
Metals and metalloids make up the majority of the Periodic Table of Elements. Some human activities such as mining, gas extraction, and emissions from combustion engines can introduce or further activate elements that naturally occur in the Earth’s crust. Metal toxicity can affect human health in a variety of ways, including the development of cancers and damage to vital organs like the liver, kidneys, and lungs. Toxic metals also target the body’s regulatory systems, leading to disruption of the endocrine system, immune system, and neurological pathways, all of which can harm development and normal bodily function.
Agencies like the Food and Drug Administration (FDA) implement policies that attempt to keep the United States’ food supply as free from metal exposure as possible, while the Occupational Safety and Health Administration (OSHA) works to keep workplaces safe and ensure workers’ health. They are authorized to take action if metal levels are deemed unsafe, yet these standards are likely out of date due to the slow-moving nature of updating government regulations. As a result, the food supply may be more contaminated than we think.
For example, the amount of lead still allowed in bottled water by the FDA is 5 parts per billion, when it is known that there is no safe level of lead whatsoever. Environmental advocacy groups like the Environmental Defense Fund urge updates to outdated laws that regulate the safe amount of metals allowed in various parts of the food supply.
The most common metal exposures include:
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Primary exposures:
Lead-lined water supply pipes
Occupational exposures
Certain fuel byproducts
Health effects:
Neurological effects, especially in young and developing children, including slowed growth, behavioral issues, and poor educational outcomes
Potential prevention:
Lead testing of water, paints, and soil in homes
Removal or replacement of lead-contaminated pipes and water supplies
Limiting children playing in soil and ensuring children’s toys are not lead-contaminate
Blood-lead testing and follow-up care if already exhibiting signs of lead poisoning
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Primary exposures:
Naturally occurring in some groundwater supplies and foods, including rice
Industrial processing
Smoking
Health effects:
Acute poisoning (vomiting, diarrhea, pain, and, in extreme cases, death)
Carcinogen precursor to skin, bladder, and lung cancers
Potential prevention:
Water testing in suspected contamination areas and provision of a safe alternative water supply if contaminate
Monitoring of population in contaminated areas
Community education on high sources of arsenic in the area, including crops (rice) and specific water supplies
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Primary exposures:
Occupational exposures in factories that produce products containing utilize mercury
Dentists and dental assistants are exposed to mercury released from amalgam fillings
Consumption of fish that have bioaccumulated large amounts of mercury
Health effects:
Decreased motor function and neuromuscular effects
Nerve response damage
Reduced cognition
Kidney failure,
Respiratory effects
Potential prevention: l
Limit consumption of large fish, especially if pregnant
Utilize mercury-free products and personal protective equipment if occupationally exposed
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Primary exposures:
Food (via plants and animals that have absorbed it),
Cigarette smoke
Welding, and/or soldering
Health effects:
Cadmium is a known carcinogen.
Acute effects include vomiting and diarrhea
Long term exposure damages the lungs and can lead to death
Potential prevention:
Those in high-risk jobs in rechargeable battery manufacturing, textiles, mining, and smelting should use proper PPE to avoid inhalation.
Consumers should avoid cigarette smoke, either by smoking or secondhand smoke, as it is high in cadmium content.
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Primary exposure:
Commonly used in the production of aviation parts as well as military equipment
Workers producing these materials are at the highest risk of exposure
Health effects:
Lung cancer
Becoming more sensitive to beryllium exposures
Fever, coughing, and weight loss
Chronic obstructive lung disorder
Pneumonia
Potential prevention:
Industry professionals such as machinists, welders, foundry workers, and even dental technicians should utilize adequate protection against the inhalation of beryllium.
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Primary exposure:
Occupational exposures for those working in industries that require welding with alloys containing chromium
Paints and dyes can also contain chromium
Health effects:
Toxic effects of chromium largely affect the lungs and skin.
All chromium compounds are known carcinogens implicated in the development of lung and nasal cancers.
Potential prevention:
The dangers of chromium is mainly inhalation through occupational exposures, especially those who work in industries that produce paint, dyes, printing and copy machines, cement, and rubber.
Adequate protection measures should be provided by employers in these industries.
This list is not exhaustive, but it constitutes some of the more commonly found cases of toxicity due to exposure to metals. The majority of exposures occur in industrial occupational settings, although the food supply is a common source of metal toxicity.
To learn more about these metals and other chemicals toxic to human health, visit the Agency for Toxic Substances and Disease Registry.
