A new study published in the journal Nature Medicine suggests that cadmium, a heavy metal used in rechargeable batteries, might cause early puberty and possibly breast cancer. The metal is known to cause kidney damage and bone disease.
Researchers at Georgetown University in Washington, D.C., found that the equivalent of the highest amount of exposure under World Health Organization (WHO) rules caused estrogen-like effects in rats.
The researchers looked at two animal models. In the first, they removed female animals’ ovaries, depriving their bodies of the ability to produce estrogen. When exposed to cadmium, the rats experienced changes normally induced by estrogen, such as enlarged uterus, thickening of the endometrial lining and thickening of the mammary gland lining. Genes normally activated by the presence of estrogen were activated in the rats without ovaries.
In a second model, the rats were given low doses of cadmium. The researchers examined the offspring of the animals exposed to cadmium and they had an earlier onset of puberty.
Studies are underway to determine whether early onset of puberty might be the cause of some breast or uterine cancers, and whether the same effects would be seen in humans.
Humans may be exposed to cadmium by eating food grown in contaminated soil or fish from tainted water, or through smoking. Industrial exposures occur in such areas a shipbuilding, welding and smelting.