People exposed to the metal cadmium in the environment have an increased cancer risk, according to Belgian researchers.
The study, authored by Dr Jan A Staessen Iuniversity of Leuven, Belgium, was reported online in The Lancet Oncology.
Cadmium, a ubiquitous pollutant in industrial nations, has toxic effects. Due to its slow half-life, it accumulates in the body over a person's lifetime. The amount of cadmium that is excreted in a person's urine can be used as a biomarker of exposure. Exposure occurs through contaminated food or water or inhalation of tobacco smoke or polluted air.
Using a random population sample of 994 participants from north-east Belgium, Staessen and colleagues prospectively investigated whether environmental exposure to cadmium is associated with an increased risk of cancer, in particular lung cancer.
The researchers studied participants from an area close to 3 zinc smelters (high exposure) and compared them with a reference population that lived in a low exposure area. Cadmium in urine was measured from 1985-89 (baseline) and incidence of cancer in these individuals was measured until June 30, 2004.
At baseline, the average concentration of cadmium was 12.3 nmol/day for those from the high exposure area compared with 7.7 nmol/day for those from the low exposure area. During a median follow up of 17.2 years, 50 fatal cancers (including 18 lung cancers) and 20 non-fatal cancers (including 1 lung cancer case) were identified. Overall cancer risk was significantly associated with a doubling of the excretion concentration of cadmium. This association remained after accounting for exposure to inorganic arsenic.