Cadmium poisoning can be lethal

Cadmium damages kidneys and weakens bones.

The cadmium in Leadville's mine water may poison the liver and kidneys, and weaken bones to the point where body weight alone causes a fracture.

The following is from the Agency for Toxic Substances & Disease Registry, U.S. Department of Health and Human Services

ToxFAQs for Cadmium

Cadmium damages the lungs, can cause kidney disease, and may irritate the digestive tract. This substance has been found in at least 776 of the 1,467 National Priorities List sites identified by the Environmental Protection Agency (EPA).

What is cadmium?

Cadmium is a natural element in the earth's crust. It is usually found as a mineral combined with other elements such as oxygen (cadmium oxide), chlorine (cadmium chloride), or sulfur (cadmium sulfate, cadmium sulfide).

All soils and rocks, including coal and mineral fertilizers, contain some cadmium. Most cadmium used in the United States is extracted during the production of other metals like zinc, lead, and copper. Cadmium does not corrode easily and has many uses, including batteries, pigments, metal coatings, and plastics.

What happens to cadmium when it enters the environment?

Cadmium enters air from mining, industry, and burning coal and household wastes.

Cadmium particles in air can travel long distances before falling to the ground or water.

It enters water and soil from waste disposal and spills or leaks at hazardous waste sites.

It binds strongly to soil particles. 

Some cadmium dissolves in water.

It doesn't break down in the environment, but can change forms.

Fish, plants, and animals take up cadmium from the environment.

Cadmium stays in the body a very long time and can build up from many years of exposure to low levels.

How might I be exposed to cadmium?

Breathing contaminated workplace air (battery manufacturing, metal soldering or welding).

Eating foods containing it; low levels in all foods (highest in shellfish, liver, and kidney meats).

Breathing cadmium in cigarette smoke (doubles the average daily intake).

Drinking contaminated water.

Breathing contaminated air near the burning of fossil fuels or municipal waste.

How can cadmium affect my health?

Breathing high levels of cadmium severely damages the lungs and can cause death. Eating food or drinking water with very high levels severely irritates the stomach, leading to vomiting and diarrhea. Long-term exposure to lower levels of cadmium in air, food, or water leads to a buildup of cadmium in the kidneys and possible kidney disease. Other long-term effects are lung damage and fragile bones.

Animals given cadmium in food or water had high blood pressure, iron-poor blood, liver disease, and nerve or brain damage.

We don't know if humans get any of these diseases from eating or drinking cadmium. Skin contact with cadmium is not known to cause health effects in humans or animals.

How likely is cadmium to cause cancer?

The Department of Health and Human Services (DHHS) has determined that cadmium and cadmium compounds may reasonably be anticipated to be carcinogens.

Is there a medical test to show whether I've been exposed to cadmium?

Tests are available in some medical laboratories that measure cadmium in blood, urine, hair, or nails. Blood levels show recent exposure to cadmium, and urine levels show both recent and earlier exposure. The reliability of tests for cadmium levels in hair or nails is unknown.

CASE STUDY

Cadmium toxicity threatening wildlife in Rocky Mountains 

By Mark Floyd
Oregon State University
July 12, 2000

CORVALLIS, Ore. - An alarming number of white-tailed ptarmigan in a large region of the southern Rocky Mountains are suffering from acute cadmium poisoning - an exposure to high concentrations of the extremely toxic trace metal. 

Scientists report Thursday in the journal Nature that 46 percent of the adult birds surveyed in a 10,000-square kilometer area in south-central Colorado were found with cadmium accumulations in their kidneys well above the toxic threshold of 100 parts per million. 

Cadmium toxicity causes kidney and liver dysfunction, brittle bones, and adversely affects reproduction and survival. 

Lead author James R. Larison, an Oregon State University professor and alpine ecologist, said the findings are not unlike those that linked the pesticide DDT to a problem of thin-eggshells in the peregrine falcon three decades ago. The implications of the toxicity go beyond a single species. 

"What we found in our study was that a particular genus of plants - willows - were 'biomagnifying' or concentrating cadmium," Larison said. "They act as biological pumps, increasing the concentrations of cadmium by two orders of magnitude. Birds eat a lot of willow, especially in the winter when other foods are scarce. 

"They aren't the only creatures to eat willow, though," he added. "The possibility exists that deer, elk, moose, snowshoe rabbits, beaver and other animals may face similar problems, just as it is possible that other plants - including some vegetables - may have the same abilities to biomagnify cadmium that willow does." 

Larison said the human health risk from eating ptarmigan likely is small, unless the internal organs are consumed. But, he added, many people eat vegetables grown in the area and these could pose a risk to human health. The former director of Sea Grant Communications at Oregon State University, Larison has spent the past four years at Cornell University pursuing his doctorate in ecology and evolutionary biology. His doctoral study was funded primarily by the National Geographic Society. Other authors in the Nature article include Gene Likens, director of the Institute for Ecosystem Studies in Millbrook, N.Y., John Fitzpatrick, director of the Cornell University Laboratory of Ornithology, and J.G. Crock, a chemist with the U.S. Geological Survey. 

The study focused on an expansive section of Colorado stretching from Denver and Fort Collins to Durango known as an "ore belt." Larison, who has returned to the OSU faculty, said abandoned mines throughout this area have "exacerbated the problem." 

Though cadmium is natural to the area, he pointed out, mining tends to mobilize potentially toxic metals. "Cadmium poisoning originally was discovered in Japan, with rice acting as a biomagnifier," Larison said. "Elderly women in particular were affected with severe osteomalacia - a condition not unlike osteoporosis. Trace amounts of cadmium can be found in almost all soils, surface waters and plants, but human activities tend to concentrate it. Mining is one obvious factor, but cadmium also is mobilized by certain industrial and agricultural practices." 

Once ingested, cadmium cannot easily be excreted from the body and accumulates, usually in the kidneys and liver. The kidneys are responsible for calcium levels in the blood, Larison said, and when cadmium levels rise and kidneys tubules fail, calcium levels drop. To compensate, the body "borrows" calcium from bones. In Japan, elderly women eating a diet heavy in cadmium-contaminated rice suffered from severe bone decalcification. 

In Larison's study, 57 percent of the adult ptarmigan had damaged kidneys and their bones contained 8 to 10 percent less calcium. 

"We also found a number of birds with bone fractures," he said. "For every one we found, there may have been others that did not survive long enough for us to discover them." 

Cadmium toxicity in predators eating ptarmigan is a concern, Larison pointed out, because they likely would eat the internal organs and the cadmium would then accumulate in their bodies as well. Ptarmigan predators include eagles and hawks, as well as foxes and coyotes. 

Though the Nature article focuses on one area in the Rocky Mountains, cadmium poisoning potentially could occur elsewhere, Larison said. 

"We happened to look at the effects just on white-tailed ptarmigan eating willows in Colorado," Larison said. "But there are some indications that the conditions for cadmium poisoning are widespread."