The Top 5 Most Dangerous Heavy Metals & How You Are Exposed

Heavy Metal

Exposure to dangerous heavy metals or insufficiency of nutritional elements affects health profoundly. Testing elements in the most appropriate sample type is important for proper assessment.

How We Are Exposed To Heavy Metals

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The Top 5 Most Dangerous Heavy Metals In The World

  1. Lithium
  2. Arsenic
  3. Cadmium
  4. Mercury
  5. Lead

heavy metals


Besides being the gold standard as a treatment for bipolar disorder, lithium also plays other important roles in our lives. The most important use of lithium is in rechargeable batteries for mobile phones, laptops, digital cameras, and electric vehicles. Lithium is also used in some non-rechargeable batteries for things like heart pacemakers, toys, and clocks.

How we get exposed to lithium

The general population may also be exposed to lithium through drinking water, including bottled water (4–7), and we recently reported that such exposure was associated with increasing thyrotropin (TSH) and decreasing free thyroxine (fT4) levels.

Exposure To Lithium Can Cause

✓ Loss of appetite,
✓ nausea,
✓ vomiting,
✓ diarrhea and
✓ abdominal pain.

If that wasn’t bad enough, Lithium can also cause the following:

✓ headache

✓ muscle weakness

✓ twitching, blurred vision

✓ loss of coordination

✓ tremors

✓ confusion

✓ seizures and

✓ coma

Lithium Impacts Pregnancy & The Thyroid

An adverse effect of lithium on the thyroid maybe even more critical during pregnancy. The thyroid gland is in charge of producing hormones that are essential for pre-and postnatal growth and cognitive development. The fetal thyroid starts developing around the fourth week of pregnancy and becomes functional near mid-gestation, which is why an appropriate maternal thyroid function is crucial for fetal development.

Hypothyroidism, a condition in which the thyroid gland is incapable of producing enough thyroid hormones, has been associated with increased risk of gestational hypertension, placental abruption, preterm delivery, and fetal loss, as well as lower birth weight, congenital hypothyroidism, and impaired neurological function.

Researchers recently found inverse associations between maternal exposure to lithium during pregnancy and birth size and hypothesize that an impairment of the thyroid hormonal system might be an underlying mechanism.

Therefore, elucidating the potential impact of lithium from drinking water on maternal thyroid function during pregnancy is important for proper development.

Read the MSDS Lithium fact sheet here.


Arsenic occurs naturally in the environment. We normally take in small amounts in the air we breathe, the water we drink, and the food we eat. People can also be exposed to arsenic in some other ways, such as in some man-made products.

How Are We Exposed To Arsenic?

In food

For most people, food is the largest source of arsenic, although much of this is likely to be in the less dangerous, organic form. The highest levels of arsenic (in all forms) in foods can be found in seafood, rice, rice cereal (and other rice products), mushrooms, and poultry, although many other foods, including some fruit juices, can also contain arsenic.


Rice is of particular concern because it is a major part of the diet in many parts of the world. It is also a major component of many of the cereals eaten by infants and young children. (Nearly all rice products have been found to contain at least some arsenic, although the levels can vary widely.)


In drinking water

Drinking water is an important and potentially controllable source of arsenic exposure. In parts of China, Taiwan, Bangladesh, and western South America, high levels of arsenic occur naturally in drinking water, and can be a major source of arsenic exposure.


Water in some areas of the United States, especially in the West, also naturally contains arsenic. Most US areas with higher levels of arsenic in drinking water are rural communities. (As discussed further down, public drinking water systems in the US are required to test for arsenic and to keep it below a certain level.)


Natural arsenic levels tend to be higher in drinking water that comes from ground sources, such as wells, as opposed to water from surface sources, such as lakes or reservoirs.


At work

Arsenic has not been produced in the United States since 1985, although it is still imported from other countries. In the past, workers in smelters and in plants that manufactured, packaged, or distributed products that contained arsenic had high exposures from breathing in arsenic fumes and dust.


Arsenic was a common ingredient in many pesticides and herbicides in the past. People who made, transported, applied, or worked around these products may have been exposed to higher levels of arsenic. Inorganic arsenic compounds have not been used in pesticides in the US since 1993, and organic compounds have been phased out of pesticides (with one exception used on cotton plants) as of 2013.


Today workplace exposure to arsenic can still occur in some occupations that use arsenic, such as copper or lead smelting, and wood treating. Regulations are in place to limit this workplace exposure.


In the community

People who live near current or former industrial or agricultural sources of arsenic can be exposed to higher levels by inhaling fumes or eating contaminated food.


Industrial buildings such as wood preservative and glass factories can contaminate nearby air, soil, and water. Communities near smelters, or near farm fields or orchards where arsenic pesticides were used, may also have contaminated soil.


Burning fossil fuels (such as coal) and tobacco can also release small amounts of arsenic into the air.


In pressure-treated wood

Some arsenic compounds, such as chromated copper arsenate (CCA), have been used as preservatives to help protect wood from rot and insects. CCA was used to pressure-treat lumber that was used in some home foundations, decks, fences, playgrounds (play sets), and other structures for many decades.


The use of CCA in pressure-treated lumber for most residential (home) uses was stopped at the end of 2003, although it is still used for industrial purposes. This was done because of concerns that some of the arsenic might leach out of the wood and enter the soil or be absorbed through the skin when the wood is touched. Wood that is frequently touched by children, such as that found in some playground equipment, is a special concern.


People can also be exposed to arsenic by breathing in sawdust from cut arsenic-preserved wood or by breathing the smoke from burning this wood.


Pressure-treated lumber for residential uses is now made with other compounds that do not contain arsenic. However, any structures built from lumber that was pressure-treated before 2004 may still contain CCA. (For more information, see “How can I limit my exposure to arsenic?”)

Arsenic affects a broad range of organs and systems including:


✓Nervous system

✓Respiratory system

✓Cardiovascular system

✓Liver, kidney, bladder and prostate

✓Immune system

✓Endocrine system

✓Developmental processes

Symptoms Of Arsenic Poisoning May Include:

✓red or swollen skin

✓skin changes, such as new warts or lesions

✓abdominal pain

✓nausea and vomiting


✓abnormal heart rhythm

✓muscle cramps

✓tingling of fingers and toes

✓Long-term exposure to arsenic can cause more severe symptoms.

You should seek emergency help if you experience any of the following after a suspected arsenic exposure:


✓darkening skin

✓constant sore throat

✓persistent digestive issues

According to the World Health OrganizationTrusted Source, long-term symptoms tend to occur in the skin first, and can show up within five years of exposure. Cases of extreme poisoning may lead to death.

Arsenic Causes Cancer

The IARC is part of the World Health Organization (WHO). One of its major goals is to identify causes of cancer.


IARC classifies arsenic and inorganic arsenic compounds as “carcinogenic to humans.” This is based on sufficient evidence in humans that these compounds can cause:


✓Lung cancer

✓Bladder cancer

✓Skin cancer

IARC also notes links in some studies to:


✓Kidney cancer

✓Liver cancer

✓Prostate cancer


Long-term actions are required to reduce exposure to arsenic from mining, metal smelting and

refining, combustion of low-grade coal, pesticide use and timber treatment. In particular,

action is needed to reduce the intake of arsenic from drinking-water and food in areas with

naturally high levels in the groundwater.


Cadmium is a metal that appears soft, malleable, and bluish-white in its elemental form. While it is a relatively widespread element, it is rarely found on its own as a pure metal and more often forms complex compounds in zinc ores. It is mainly produced through the process of smelting, mining, and refining zinc, lead, and copper.


Cadmium has many uses, including the manufacture of rechargeable batteries. Exposure to cadmium can affect the kidneys, lungs and bones. Cigarette smoke contains high levels of cadmium. Blood and urine tests can measure the amount of cadmium present in the body.


While it found initial use as a dye for producing shades of yellow, orange, and red, cadmium today is most widely used in nickel-cadmium rechargeable batteries. It is also found in:


✓Plating on iron and steel products

✓Plastic stabilizers

✓Alloy elements for lead, copper, and tin

✓Cigarette smoke


Along with its status as an industrial byproduct, cadmium is a natural component of the earth’s crust and mantle and can easily enter the atmosphere, water, and soil. This can happen through volcanic activity, weathering of sediment, and the burning of fossil fuels.


This can lead to cadmium’s presence in sources of drinking water and food, including




How Do We Get Exposed To Cadmium

Worker exposure to cadmium can occur in all industry sectors but mostly in manufacturing and construction. Workers may be exposed during smelting and refining of metals, and manufacturing batteries, plastics, coatings, and solar panels. The expanding Ni-Cd battery recycling industry is a concern for cadmium exposure.

Electroplating, metal machining, welding, and painting are operations associated with cadmium exposure. Workers involved in landfill operations, the recycling of electronic parts, or the recycling of plastics may be exposed to cadmium. Compost workers and waste collectors are also potentially exposed to dust which may contain cadmium. The incineration of municipal waste is another source of cadmium exposure.

However, food sources can be contaminated as well. Cadmium exposure occurs from ingestion of contaminated food (crustaceans, organ meats, leafy vegetables, rice from certain areas of Japan and China) or water (either from old Zn/Cd sealed water pipes or industrial pollution) and can produce long-term health effects.

Other jobs that are associated with the occupational exposure of cadmium include:



✓Metal machining

✓Landfill operations

✓Recycling of electronic parts or plastics

✓Composting and general waste collection (from dust or incinerating municipal waste)

Add Your Heading Symptoms Of Cadmium Exposure
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Breathing in cadmium can result in:

✓Flu-like symptoms, such as body aches, chills, and weakness.

Eating food or drinking water contaminated with high levels of cadmium can result in:

✓Nausea and vomiting.

✓Stomach cramps.


✓Kidney damage.

✓Fragile bones.



Mercury exists in various forms: elemental (or metallic) and inorganic (to which people may be exposed through their occupation); and organic (e.g., methylmercury, to which people may be exposed through their diet).


These forms of mercury differ in their degree of toxicity and in their effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes.


Mercury occurs naturally in the earth's crust. As a result of volcanic activity, weathering of rocks and human activity it is released into the environment.

Human activity is the main cause of mercury releases, particularly coal-fired power stations, residential coal burning for heating and cooking, industrial processes, waste incinerators and as a result of mining for mercury, gold and other metals.

Mercury can be transformed by bacteria into methylmercury in the environment.

Methylmercury then bioaccumulates (bioaccumulation occurs when an organism contains higher concentrations of the substance than do the surroundings) in fish and shellfish. Methylmercury also biomagnifies. For example, large predatory fish are more likely to have high levels of mercury as a result of eating many smaller fish that have acquired mercury through ingestion of plankton.

Mercury is contained in many products, including:


✓measuring devices, such as thermometers and barometers

✓electric switches and relays in equipment

✓lamps (including some types of light bulbs)

✓dental amalgam (for dental fillings)

✓skin-lightening products and other cosmetics


How Mercury Exposure Happens

People may be exposed to mercury in any of its forms under different circumstances. However, exposure mainly occurs through the consumption of fish and shellfish contaminated with methylmercury and through worker inhalation of elemental mercury vapors during industrial processes.


Important Note!: Cooking does not eliminate mercury.


Metallic mercury mainly causes health effects when inhaled as a vapor where it can be absorbed through the lungs. Symptoms of prolonged and/or acute exposures include: Tremors; Emotional changes (such as mood swings, irritability, nervousness, excessive shyness)


Nearly all methylmercury exposures in the United States occur through eating fish and shellfish that contain higher levels of methylmercury.

Sources of common potential exposure to metallic mercury are described below.


Fever thermometers

It is not uncommon for children to break fever thermometers in their mouths. When a thermometer containing mercury breaks in a child's mouth and the child might have swallowed some mercury, be aware that the mercury poses a low risk in comparison to breathing mercury vapor.

Learn what to do if a mercury thermometer breaks in your home or school (outside of someone's mouth).


Novelty jewelry

Some necklaces imported from Mexico contain a glass pendant that contains mercury. The mercury-containing pendants can come in various shapes such as hearts, bottles, balls, saber teeth, and chili peppers. If broken, they can release metallic mercury to the environment.

Other consumer products: Metallic mercury is often found in school laboratories. It is also in some thermometers, barometers, switches, thermostats, and electrical switches. View a list of products that contain mercury.


Dental fillings

Mercury is used in dentistry in dental amalgam, also known as "silver filling." Dental amalgam is a direct filling material used in restoring teeth. It is made up of approximately 40-50% mercury, 25% silver, and 25-35% blend of copper, zinc and tin. Amalgam use is declining because the incidence of dental decay is decreasing, and because well-performing substitute materials are available for restoring teeth. Learn more about mercury in dental fillings.


Gold mining

Metallic mercury is sometimes used in artisanal and small-scale gold mining at locations outside of the United States. Mercury is mixed with gold-containing materials, forming a mercury-gold amalgam. The amalgam is then heated, vaporizing the mercury and leaving the gold. This process is very dangerous and can lead to significant mercury exposure. Miners working tailings in areas where mercury was previously used can also be inadvertently exposed to the residual mercury in these deposits. Learn more about mercury pollution from artisanal and small-scale gold mining.


Being exposed to mercury can lead to hallmark signs of toxicity as described below.


See the WHO fact sheet on mercury.

Early Symptoms Of Mercury Poisoning

Mercury may affect the nervous system, leading to neurological symptoms such as:


✓nervousness or anxiety

✓irritability or mood changes


✓memory problems


✓physical tremors

As the levels of mercury in the body rise, more symptoms will appear. These symptoms may vary depending on a person’s age and exposure levels. Adults with mercury poisoning may experience symptoms such as:


✓muscle weakness

✓metallic taste in the mouth

✓nausea and vomiting

✓lack of motor skills or feeling uncoordinated

✓inability to feel in the hands, face, or other areas

✓changes in vision, hearing, or speech

✓difficulty breathing

✓difficulty walking or standing straight

Mercury can also affect a child’s early development. Children with mercury poisoning may show symptoms such as:


✓impaired motor skills

✓problems thinking or problem-solving

✓difficulties learning to speak or understanding language

✓issues with hand-eye coordination

✓being physically unaware of their surroundings

Long Term Symptoms Of Mercury Poisoning

Mercury poisoning tends to develop slowly over time if a person comes into frequent contact with mercury. However, in some cases, mercury poisoning comes on quickly and is associated with a specific incident.


High levels of mercury in the blood may put a person at risk for long-term neurological damage. These effects may be more pronounced in children who are still developing.


A study in the Journal of Preventive Medicine and Public HealthTrusted Source noted that many incidents of mercury poisoning have led to long-term nerve damage, which can cause:


✓intelligence disorders and low IQ

✓slow reflexes

✓damaged motor skills



✓problems with memory and concentration

✓symptoms of ADHD


Reproductive effects


Mercury poisoning also poses a risk to the reproductive system. It may cause reduced sperm count or decreased fertility and may also cause problems with the fetus.


Possible effects of mercury poisoning include deformity and a decreased survival rate of the fetus, and reduced growth and size of the newborn at birth.


Cardiovascular risks


Mercury helps promote the accumulation of free radicals in the body, which puts the cells at risk for damage. This may lead to an increased risk of heart problems, including heart attack and coronary heart disease.


Lead is found everywhere like many other heavy metals. It is naturally occurring in the crust of the earth but most human exposure is human made. Lead has the ability to travel via air from industrial sources and then land in the soil you use to garden or your farmer uses to grow those yummy vegetables. Thanks to federal, state, and local regulations, lead exposure isn’t nearly that of what it used to be. Most at-risk populations include children (no chewing on the window sills kiddos) and pregnant women as the lead may be transferred to the developing fetus.

Lead has the potential to affect nearly every organ in the body. This is why children are often screened for lead levels early on in development.

Symptoms of lead toxicity range from but are not limited to:

✓Delayed growth


✓Lower IQ


✓Reproductive problems

✓Decreased Kidney function

✓Auditory concerns

✓Cardiovascular symptoms such as hypertension

How to lower your risk of exposure?

✓Wash hands before eating after spending time outside in the soil.

✓Remove shoes before or upon entering your home (remember children are most at risk, crawlers!)
✓Increase nutrients calcium, vitamin C, and iron. The nutrients help decrease the absorption of lead.

✓If your house was built before 1978 test your home for lead.There are licensed lead inspectors that do exactly this.

✓Vacuum and dust regularly

✓Purchase a high quality HEPA air purifier and change HVAC air filters routinely.

What we have to do is ask “why?”

Nearly all patients I see ask about heavy metal toxicity. My most common answer is that heavy metals are simply unavoidable, however toxicity in most cases can be prevented by making some diet and lifestyle modifications.


  1. Why, if diagnosed or symptomatic, are we experiencing that toxicity?
  2. What in our environment is triggering this?
  3. When considering any toxicity we first have to consider the function of our bodies' detox pathways; lungs, kidneys, skin, colon, and liver. Are these organs working properly?
  4. What can we do to optimize function?
  5. How often is the patient having a bowel movement, urinating, do they sweat, are we seeing skin concerns such as acne, do they struggle with frequent respiratory illnesses?
  6. All of this clinical insight can give us a general idea of how well the individual is able to detox any type of pathogen.

Suggestions For Detox

If the patient has done a functional heavy metal test we can pinpoint the specific toxicity and develop a targeted protocol to aid in elimination. Most often these treatments start in the gut by introducing foods and supplements known to help eliminate the most common toxic heavy metals.


My personal favorite and something that is safe to take daily as a preventative supplement is Spirulina and Chlorella. I love the tablets you can just give a gentle chew and swish them down with water. Just make sure you buy from a practitioner dispensary or reputable source for quality.


Some other detoxifying foods include: lemon, cilantro, garlic, blueberries, curry, barley grass juice, and of course probiotics! (you can literally throw all of that into a blender and be well on your way to detoxification!)


I also advise avoiding non-organic foods and all alcohol until confirmed toxicity is gone .


The main idea here is to get pooping. To think of your food as a giant broom scraping out your digestive tract and getting rid of anything larger than what is meant to be there in the first place. We also want to consider the other pathways, so get sweating, increase exercise and drink plenty of fluid to support skin and kidneys. Hydration will also protect the mucosal lining of the lungs which will make it inhospitable for heavy metals.

Key takeaways.

  1. Don’t give heavy metals a “seat at the table”. Be sure to eat a healthy, well-balanced diet. Increase your intake of nutrients and minerals. This leaves less space for toxic build-up! Our bodies contain receptor cells that pick up nutrients and pathogens so if those receptors are full of nutrients, I'll let you do the math!


  1. Lemon water every morning upon waking will give your liver a nice little jump start and prep it for a day of hard work.


  1. Rest and reset to properly digest. Eating your last foods around 7 pm and not eating again until breakfast can allow your digestive system the time to “do the work”. This work is incredibly important especially in terms of detoxification.


  1. Give your cells the best chance possible by increasing antioxidants. Vitamin C, think lots of fruits and veggies high in fiber such as beats, Kale, spinach, raspberries, blueberries, strawberries, artichokes, pecans, and the list goes on.


  1. Test your blood, I can’t say this enough. Know your own risk. Find out your specific environmental exposures and take steps to eliminate or adapt to them. Such as vacuuming more often. Wearing a mask if you work in a high-risk environment. Avoiding certain foods or supplements until your body is detoxed and restored.

The most important thing is to not fear them. Heavy metal exposure is impossible to avoid. Control what you can and that is setting a healthy foundation for your body systems.

However, you can be aware if you are building up amounts in your body that are going to cause trouble for you in the future by testing here.

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