Johns Hopkins medical researchers report that people with higher levels of cadmium in their urine appear to be nearly 3.5 times more likely to die of liver disease than people with lower levels.
Cadmium in the urine is evidence of chronic exposure to the heavy metal in industrial emissions and tobacco smoke, the researchers explain. The metal has a long chemical half-life and accumulates in the body over time, according to the Hub. The researchers say long-term exposure is known to cause kidney disease and has been linked to lung cancer. Studies have shown that long-term exposure to low levels of cadmium increases cancer mortality.
The scientists caution that their findings do not show that cadmium directly causes liver disease, but they say the association needs further investigation, according to the Hub, a Johns Hopkins news website. “We already know about the health hazards of heavy metals like lead and mercury, but we don’t know much about what cadmium does to the body,” says Omar Hyder, the study’s leader. Hyder is a postdoctoral fellow in the Department of Surgery at the Johns Hopkins University School of Medicine. He and his colleagues reviewed information from a large population-based survey; their findings were published online in the Journal of Gastrointestinal Surgery.
Tobacco smoke is the single most important source of cadmium exposure. Fossil fuel combustion and municipal waste incineration also expose people to cadmium. For many years, the Hub reports, most batteries in the United States were made with cadmium, and cadmium can be found in pigments and plastics.
The researchers discovered that the cadmium-liver disease link disproportionately affects men, according to the Hub. They say that menopause chemistry may protect women by redistributing stored cadmium from their liver and kidneys, where it can do more damage, and into bones, where it remains more stable.