Sources of Heavy Metals
There are many sources of heavy metals in the environment, as well as the foods, drinks and pharmaceuticals that we intake. Below are some of these sources, even though there are many more that could be added. Heavy metals are now ubiquitous in today’s world, and everyone on the planet has some degree of heavy metal toxicity, including our infants that get their toxic load while living in mother’s womb.
Mercury
- Metal amalgams (dental fillings): Metal amalgams are composed of 50% mercury by elemental weight. These fillings should be removed and replaced with composite (white) fillings. The removal process can often lead to more exposure to the element. Ensure that your dentist is properly trained in safely removing amalgam fillings. Some resources that can aid in finding a dentist in your area are:
- https://iaomt.org/
- https://iabdm.org/
- http://amalgam.org/
- http://www.toxicteeth.org/
- Seafood: Larger fish have a higher concentration of mercury. Smaller fish like shrimp, light tuna, and salmon are lower risk, and can be consumed twice a week safely. Sushi can be high in mercury, with just one portion of tuna sashimi exceeding the PTWI mercury intake allowance [3]. Pregnant women are advised to avoid fish.
- Gold mining: Mercury is sometimes used to separate gold from other materials. Residual mercury in areas where this technique was used can also expose miners.
- Pharmaceutical products: Mercury is used in small amounts in some drugs. A list of such products is found here.
- Fever thermometers: These can break in the patient’s mouth, leading to the ingestion of mercury.
- Jewellery: Some jewellery, usually coming from Mexico, can contain mercury.
- Automotive Parts: Cars built before 2003 may contain mercury relays and switches.
- Electronics & Batteries: LCD screens and some batteries contain mercury, and must be disposed of at hazardous waste collection centers. Avoid breaking these products.
- Light bulbs: Breaking a fluorescent bulb, high intensity discharge lamp, ultraviolet lamp, or neon lights can lead to exposure to mercury.
Lead
- Drinking water: Lead enters drinking water primarily due to lead pipes in old houses. The water source itself can also be contaminated. Have your water tested for lead, in many places the city will do this free of cost.
- Paint: Lead paint was used before 1978, so older homes are usually a source of lead. This becomes a concern when chips turn to dust.
- Air: Air can become contaminated due to combustion of leaded gasoline, soldering with lead-based solder, lead-acid batteries, and waste incinerators.
- Cosmetics: Some make-up contains lead; this becomes especially problematic for lipsticks that are easily consumed inadvertently [5].
- Supplements: Supplements can be contaminated with heavy metals, as seen in Labdoor’s evaluation of products. It’s important to only consume third-party tested supplements that have a good reputation for quality.
- The Workplace: “Some jobs that expose people to lead include home improvement; painting and refinishing; car or radiator repair; plumbing; construction; welding and cutting; electronics; municipal waste incineration; lead compound manufacturing; manufacturing of rubber products, batteries, and plastics; lead smelting and refining; working in brass or bronze foundries; demolition; and working with scrap metal.” [6]
- Ceramic glaze: Plates, ceramic pans, and China can be glazed in ceramics that contain lead and cadmium.
- Children’s toys and jewellery: Some of the toys that come from vending machines contain lead.
- Juice: Arsenic, lead and/or cadmium have been detected in different juices. In thisreport 45 juices were tested, 21 of which contained an unsafe amount of metals.
- Vegetables grown in contaminated soil: This is usually not a concern in North American. However, in some areas (like parts of Japan) soils can be contaminated, leading to vegetables with higher-than-normal levels of heavy metals.
- Other Sources: Imported candies and foods (usually form Mexico), imported cans that are sealed with a lead solder, lead bullets, radiators, some ink, and batteries.
Arsenic
- Seafood: Arsenic is a naturally occurring element in seawater. Smaller fish like shrimp, light tuna, and salmon are lower risk, and can be consumed twice a week (two meals) safely.
- Drinking Water: Arsenic is naturally present at high concentrations in Argentina, Bangladesh, Chile, China, India, Mexico, and the USA [7]. Drinking water from shallow groundwater sources that are not sufficiently treated can expose people to arsenic.
- Rice: Rice has a high affinity for arsenic, causing it to absorb large amounts of the metal. Rice grown in California is slightly less contaminated than rice from other regions. Soaking rice overnight can reduce concentrations
- Supplements: Supplements can be contaminated with heavy metals, as seen in Labdoor’s evaluationof products. It’s important to only consume third-party tested supplements that have a good reputation for quality.
- Beer & Wine: These drinks are often filtered to strain out sediment that may leave the drink looking cloudy. However, the diatomaceous earth filter often used is a source of arsenic. Some beer was determined to have >25ppb of arsenic, while the limit for drinking water is 10ppb.
- Brussels Sprouts: Much like rice, brussels sprouts simply have a high affinity for arsenic in soil. People who regularly consumed brussels sprouts had a 10.4% higher level of arsenic than people who never ate them.
- Juice: Arsenic, lead and/or cadmium have been detected in different juices. In thisreport 45 juices were tested, 21 of which contained an unsafe amount of metals.
- Vegetables grown in contaminated soil: This is usually not a concern in North American. However, in some areas (like parts of Japan) soils can be contaminated, leading to vegetables with higher-than-normal levels of heavy metals.
Cadmium
- Cigarettes: Smokers usually have double the blood and body cadmium levels of non-smokers [8].
- Supplements: Supplements can be contaminated with heavy metals, as seen in Labdoor’s evaluation of products.It’s important to only consume third-party tested supplements that have a good reputation for quality.
- Metal processing (like smelting): Limits for cadmium fumes in the workplace is 1 mg/m3, cadmium in air usually only reaches 4 x 10-5mg/m3 [9]. In most workplaces, even metal processing plants, this shouldn’t be a dangerous level of cadmium exposure.
- Vegetables grown in contaminated soil: This is usually not a concern in North American. However, in some areas (like parts of Japan) soils can be contaminated, leading to vegetables with higher-than-normal levels of heavy metals.
- Ceramic glaze: Plates, ceramic pans, and china can be glazed in substances that contain lead and cadmium.
- Dark chocolate: Cacao trees readily absorb cadmium from their surrounding environment. This is particularly an issue in South American countries due to the volcanic soil found there.
- Juice: Arsenic, lead and/or cadmium have been detected in different juices. In thisreport 45 juices were tested, 21 of which contained an unsafe amount of metals.
References
[1] https://www.fda.gov/medical-devices/dental-amalgam/about-dental-amalgam-fillings
[2] https://www.epa.gov/mercury/how-people-are-exposed-mercury
[3] https://www.ncbi.nlm.nih.gov/pubmed/28272991
[5] https://www.ncbi.nlm.nih.gov/pubmed/19250956
[6] https://www.health.ny.gov/environmental/lead/sources.htm
[7] https://www.who.int/news-room/fact-sheets/detail/arsenic
[8] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5664655/
[9] https://www.atsdr.cdc.gov/csem/csem.asp?csem=1&po=5
[10] https://www.ncbi.nlm.nih.gov/pubmed/29310543
[11] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3229679/
[12] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5502079/
[13] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5305985/
[14] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5977413/
[15] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3907042/