Do you wonder if you have high levels of heavy metals in your system – like mercury, lead, or cadmium? Or maybe you’ve already been tested, and you know you do have a higher than normal level of one or more of these toxic metals. If that is the case, then you should be conferring with your health-care professional to determine your best course of action.

But how can exposure to heavy metals be avoided? Let’s look at the common ways you can be exposed – and thus, avoid exposure.

Mercury: seven types of fish to avoid

The most common source of mercury exposure is from eating fish. If you have been tested and know you have a high level of mercury, then it is best to avoid eating fish. If you are trying to prevent mercury exposure, check out the FDA's guidelines on eating fish.

The fish species that contain the highest levels of mercury are:

  1. Swordfish
  2. Shark
  3. Tilefish
  4. King mackerel
  5. Orange roughy
  6. Tuna
  7. Marlin

However, the FDA still advises limiting fish consumption in general, and particularly advises being aware of local advisories about eating fish from specific bodies of water that have mercury contamination.

Specific guidelines for women of childbearing age

Here are three important FDA guidelines on managing fish consumption if you are a woman of childbearing age (ages 18-49). First, when eating fish, eat a variety whenever possible. Second, if you eat fish caught by family or friends, check online for fish advisories. And if there is no advisory, only eat one serving and no other fish that week. 

Third, if you consume fish weekly, the FDA recommends that you eat 2-3 servings weekly from the “Best Choices” list OR one serving weekly from the “Good Choices” list – AND avoid the seven types of fish commonly contaminated with high levels of mercury that are listed above.

Download the lists of best choices and good choices for fish consumption from fda.gov.

Fish are not the only source

Common personal care products that can contain mercury include tattoo inks, hair dye, cosmetics, and skin-lightening formulas. It is always good to read the product label, especially on the products you use regularly. It is important to remember that everything you put on your skin or hair can end up in your body.

In addition, mercury has been used as a preservative in plastics and cleaning solutions.

There are simple steps you should take now to ensure that your personal care regimen is safe. First, check the product labels of the personal care products you use. Second, stop using the product immediately if you see the words “mercurous chloride,” “calomel,” “mercuric,” “mercurio,” or “mercury.” Third, do not use a foreign product unless the label describes the ingredients in English.

What about the fillings in your mouth?

Mercury is commonly found in dental amalgam – “silver fillings” – that dentists have used for over a century to repair cavities. This form of dental amalgam is usually one-half mercury, with the remainder consisting of silver, copper, and tin. The problem is, dental amalgam can break down, and when you chew or drink hot beverages, a small amount of mercury vapor from a filling can be released, which you can then inhale and absorb.

The World Health Organization recommends that a “phase down should be pursued by promoting disease prevention and alternatives to amalgam.” If you have silver fillings, it is recommended that you consult with your dentist. 

What about lead?

Lead-containing paint used in homes built before 1978 and drinking water contaminated from corroded lead pipes are two of the most common sources of lead exposure. If you have a high level of lead in your blood, then a licensed lead inspector can identify whether your house is a source of lead exposure.

If you plan to remodel a home built before the lead paint ban in 1978, then have it inspected first, because sanding or scraping paint can create dangerous lead dust. Children are at particular risk for ingesting lead dust. Wear gloves and a face mask, use wet paper towels to clean up lead dust, and wash toys with soap and water. Use duct tape as a temporary measure to cover peeling paint.

Water pipes – a source of lead

Lead can enter drinking water when lead-containing service pipes corrode. The most common problem, according to the EPA, is with brass or chrome-plated brass faucets and fixtures put together using lead solder, from which lead can enter the water, especially hot water. Individuals can also be exposed to lead from old lead water pipes or the lead solder used to weld copper water pipes. In fact, about 15-20% of total lead exposure is attributed to lead released from old pipes used to deliver drinking water.

Excessive levels of lead have been found in nearly 2,000 municipal water systems across all 50 states. But even in cities where the municipal system complies with lead guidelines, the lead level in an individual house can still be high. Do not rely on the municipal water system’s lead report. The level of lead in a home’s drinking water is best determined by sending a tap water sample to a testing company.

What about occupational exposure?

The soil and water in areas where mining activities have occurred can be very contaminated with lead. Other workplaces where the risk of lead exposure is higher include automotive manufacturing or repair, industrial construction, welding, battery manufacturing, ceramic or pottery production, and plastic and rubber manufacturing. If you work in one of these environments, then it is important to talk to your health-care professional about your working conditions.

Cadmium in tobacco smoke

In addition to the well-known health hazards of smoking, smoking increases the exposure risk to heavy metals – cadmium in particular. Research shows cadmium levels are twice as high in smokers than in non-smokers. Cadmium in the soil is efficiently absorbed by tobacco plants and distributed throughout the whole plant. In fact, tobacco plants accumulate high levels of cadmium.

The amount of cadmium in a cigarette and its impact on the smoker depends on numerous factors, including tobacco blend types and cigarette design. For example, the transfer of cadmium from the cigarette to its smoke is lower in cigarettes with carbon filters. One study found that cadmium was present in 26 different brands of cigarettes purchased in eight different countries in 16 different samples.

Cadmium in soil

While cadmium occurs naturally in the soil, it also occurs as an industrial byproduct. In fact, the accumulation of cadmium in the soil mainly occurs from the use of fertilizers, waste water, sewage sludge, and manures.

You can be exposed to cadmium in your diet, because cadmium can be absorbed into plants, such as rice, that are grown in high-cadmium soil. Soil from areas that formerly grew tobacco, such as in the southeastern United States, tend to be particularly high in cadmium. Water that contains cadmium can contaminate shellfish like oysters, scallops, and mussels.

Organ meats like liver and kidney also tend to concentrate cadmium.

Although leafy vegetables, root vegetables, and cereal grains like rice can be high in cadmium, depending on the soil they are grown in, other ingredients in these plant-based sources of cadmium, like fiber, tend to partially inhibit the absorption of cadmium. Furthermore, antioxidants and other beneficial nutrients in plant-based foods can partially offset the toxic effects of cadmium.