Description

Cadmium is a heavy metal that occurs naturally in some soils and rocks. It is known to cause cancer in humans. Cadmium levels build up in the body over time and remain in the body.

Cadmium is used in various types of compounds. Cadmium sulfide is the most widely used cadmium compound and is used mainly in pigments. Cadmium is also used in batteries, photovoltaic cells, and infrared windows, metal coatings and electroplating, electrical components, paints, plastics (primarily polyvinyl chloride, or vinyl), ceramic glazes, and textile dyes. It is also an additive used in Teflon. Fertilizers used to grow food may contain cadmium. Shellfish, liver, and kidney can accumulate high levels of cadmium.

Cadmium is released into the environment by the burning of coal, diesel fuel, gasoline and other fossil fuels, incineration of municipal waste, and from polluting metal alloy and electroplating facilities. Cadmium is present in vehicle tires and consequently in the particles resulting from tire wear. Cadmium is also emitted in tobacco smoke. In the past, cadmium was used as a fungicide for golf courses and home lawns, but by the late 1980’s the EPA banned all fungicide uses.

Children are most likely to be exposed to cadmium through food and tobacco smoke. Younger individuals absorb and may even proportionally accumulate more cadmium than adults.

Health Effects

Immediate Health Effects

If SWALLOWED, cadmium is Very Highly Toxic
If ABSORBED THROUGH SKIN, cadmium is minimal
If INHALED (SNIFFED OR BREATHED IN), cadmium is Very Highly Toxic

Longterm or Delayed Health Effects

Suspected Endocrine Disruptor = May interfere with, mimic or block hormones
Development Toxicant = Can interfere with normal development of a fetus or child
Reproductive Toxicant = Can harm reproductive system

Other

Inhaling high levels of cadmium (e.g., by industrial workers) can cause severe lung damage and irritation, with shortness of breath, dry throat, heachache, vomiting, extreme restlesness or irritability, chest pain, cough, and a buildup of fluid in the lungs. In severe cases, this may result in death or permanent lung damage and emphysema. Most cadmium levels found in the environment are not high enough to cause lung damage.
If ingested at high levels in foods or water, can cause stomach irritation, nausea, vomiting, salivation, cramps, diarrhea, anemia, convulsions, shock, kidney failure, and sometimes death. Short-term health effects include flu-like symptoms, such as chills, headache, aching and/or fever.
Repeated low-level exposures to cadmium can cause kidney damage, leading to stones and tubular-cell death in the kidneys; liver damage; and weakening of bones, causing bone and joint pain and osteoporosis. Long-term exposure can also cause anemia, loss of sense of smell, fatigue, and/or yellow staining of teeth. Cadmium appears to depress some immune functions, mainly by reducing resistance to bacteria and viruses.
Cadmium causes lung cancer and may also be linked to prostate, kidney and bladder cancers in humans.
Cadmium may affect the human endocrine (hormone) system. In test tube studies it behaves like the female sex hormone estrogen. One study found a link between elevated cadmium levels in blood and a decrease in sperm motility and an increase in abnormal sperm morphology and serum testosterone. It may damage the testes (male reproductive glands) and affect the female reproductive cycle.
The offspring of test animals exposed to cadmium during pregnancy had decreased weight gain, effects on the skeleton, and deficits in behavior and learning ability. Cadmium causes brain damage to newborn animals, whereas adults are resistant to these effects. There may be a potential increase in risk of decreased birth weight or developmental problems for humans, but these effects have not been observed. Cadmium can enter breast milk.

How Exposures Occur

Human Breast Milk

Cadmium levels in human milk can range from 5 to 10% of the levels found in the mother’s blood.

In Drinking Water

Children can ingest cadmium from drinking contaminated water. Cadmium may leach into groundwater from galvanized zinc pipes containing a cadmium impurity, cadmium in solder used on copper pipes, or from hazardous waste sites.

In Food

Children may be exposed to low levels of cadmium in foods. Shellfish (clams, oysters, mussels, lobster, crab, shrimp) and organ meats (liver or kidney) typically contain the highest cadmium levels. Sunflower seed kernels also can contain relatively high levels of cadmium. The largest contributors of cadmium in the diet, after shellfish, are green leafy vegetables, cereal grains, potatoes, and milk. The application of phosphate fertilizers and sewage sludge may increase cadmium levels in soil, which, in turn, elevates cadmium levels in food crops. Food is the principal means of exposure to cadmium for non-smokers.

Prenatal Exposure

Cadmium does not readily transfer from a woman’s body into the developing child, but some can cross the placenta.

Rechargeable Batteries, Electronic Equipment, and Other Products

When rechargeable batteries, electronic equipment, or other products made with cadmium are discarded or burned rather than recycled, they can release cadmium into the environment.

Glazes for ceramics and glass, some fabric dyes used by home hobbyists, and some fertilizers, as well as fungicides purchased before 1997, may also contain cadmium.

Vinyl

Small children may be exposed to traces of cadmium if they chew vinyl toys, rain coats, umbrellas, clothing, backpacks, ponchos, school supplies, purses, and sports equipment. Traces of cadmium dust may form on the surface over time. Children might ingest small amounts if they chew these items or put their fingers in their mouths after touching cadmium-contaminated dust. Dermal exposure (through the skin) is not a problem, however.

In Polluted Air or Dust

Children can inhale cadmium when they are exposed to secondhand cigarette smoke. Most smokers have about twice as much cadmium in their bodies as nonsmokers.

Children can breathe in low levels of cadmium from air in industrial areas near zinc, lead or copper smelters, fossil fuel-burning utility plants, and municipal waste incinerators.

Children may also breathe or ingest dust or soil particles contaminated with cadmium.

Significant Statistics

Cadmium has been found in at least 1,014 of the 1,669 National Priorities List sites identified by the Environmental Protection Agency.

Cadmium. Agency for Toxic Substances and Disease Registery. September 2008. http://www.atsdr.cdc.gov/tfacts5.pdf.

In 2008, estimated cadmium metal production in the United States was 777 metric tons, 6% higher than 2007. Apparent consumption of cadmium was 550 tons, a 6% decrease from the previous year.

Tolcin, Amy C. 2008 Minerals Yearbook: Cadium (Advance Release). US Geological Survey. October 2009. http://minerals.usgs.gov/minerals/pubs/commodity/cadmium/myb1-2008-cadmi.pdf.

US cadmium production has declined recently because of environmental and toxicity concerns. US production of cadmium compounds was 670 metric tons in 1999 and decreased to 33 metric tons in 2002.

Report on Carcinogens, Eleventh Edition; U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s028cadm.pdf.

Cadmium’s use in all industries has declined in recent decades except for battery use. Battery use grew from 8% in 1970 to 75% in 2000.

Report on Carcinogens, Eleventh Edition; U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s028cadm.pdf.

Solutions

How to detect cadmium

If you live near a source of cadmium pollution, you may want to also test your garden soil for cadmium before eating foods grown in it.
Community water systems are required to produce annual consumer confidence reports and mail them to every water customer. The Safe Drinking Water Act requires that community water systems monitor cadmium levels, and make public when levels exceed the set Maximum Contamination Level (MCL). The MCL for cadmium has also been set at 5 parts per billion.
If your water source is a well, your water is not monitored for contaminants as is required for public water supplies by the Safe Drinking Water Act. Private testing of the water is necessary. If you live near a hazardous waste site, landfill, or metal smelter and draw your drinking water from a well, you may want to have your water tested for cadmium contamination.

Even if your water comes from a community water system, contaminant levels can vary from house to house. You can have your water tested by sending samples to a certified laboratory.

You can search for water quality reports from your water provider, obtain information on well water testing and find a list of state-certified drinking water laboratories at the U.S. Environmental Protection Agency’s Office of Water’s website or call the EPA’s Safe Drinking Water Hotline, 800-426-4791.
Most rechargeable batteries are nickel-cadmium, often abbreviated as Ni-Cad. Small children may mistake ni-cad batteries for toys and may accidentally swallow them. If the
battery case is damaged, then some cadmium could escape and come in contact with the stomach or intestines. Keep Ni-Cad batteries out of the reach of small children, and teach your older children that the contents in Ni-Cad batteries can be harmful to their health if swallowed or burned.
Read labels on solders, glazes, dyes, fertilizers before purchase or use. Try to avoid those that list cadmium or a cadmium compound as an ingredient.

How to minimize exposure to cadmium

If you use products that may contain cadmium, make sure you are using them in a well-ventilated area and are instructed in the proper use of a respirator.
Keep all nickel-cadmium (Ni-Cad) rechargeable batteries out of reach of children. Recycle them when they’ve lost their final charge to keep them out of the waste stream. To find a recycling drop-off site, contact the Rechargeable Battery Recycling Corporation, which has set up collection sites at numerous home stores across the country. See the RBRC website, or call 800-8-BATTERY, to find your nearest drop-off site.
Reduce your children’s exposure to secondhand cigarette smoke by making your home a smoke-free zone.
If tests on your well water supply have shown higher than permissible levels of cadmium, install a water filtration system to reduce cadmium in your drinking water. The following water filtration/treatment methods have been approved by EPA for removing cadmium: Coagulation/Filtration, Ion Exchange, Lime Softening, and Reverse Osmosis.
Recycle old computers and electrical equipment whenever possible. Visit NextWorth to get rid of some old electronics or media. You can also trade unwanted media (as well as books) for media you want at Swaptree. Check with your computer’s manufacturer to see if it has a take-back program.

Alternatives

Eating a nutritious diet that is high in zinc, iron and calcium, and has plenty of protein and other nutrients, and low in fat, will minimize your body’s absorption of cadmium.
Natural fiber clothing and wooden or cloth toys do not contain cadmium stabilizers, as vinyl does.

For More information

Books, articles, factsheets and reports

Cadmium. Agency for Toxic Substances and Disease Registery. September 2008. http://www.atsdr.cdc.gov/tfacts5.pdf.

Tolcin, Amy C. 2008 Minerals Yearbook: Cadium (Advance Release). US Geological Survey. October 2009. http://minerals.usgs.gov/minerals/pubs/commodity/cadmium/myb1-2008-cadmi.pdf

Other government agencies

Agency of Toxic Substances and Disease Registry

Division of Toxicology
1600 Clifton Road E-29
Atlanta, GA 30333
800-447-1544

http://www.atsdr.cdc.gov

U.S. Environmental Protection Agency

Office of Ground Water and Drinking Water
Ariel Rios Building
1200 Pennsylvania Avenue, NW
Washington, DC 20460-0003
Safe Drinking Water Hotline:
800-426-4791

http://www.epa.gov/safewater/

U.S. Food and Drug Administration

Center for Food Safety and Applied Nutrition
5600 Fishers Lane
Rockville, MD 20857-0001
888-INFO-FDA (1-888-463-6332)

http://www.cfsan.fda.gov