Mortality by cancer in groups of the Belgian population with a moderately increased intake of arsenic

Object: The dose-response relationship for lung carcinoma and other cancers at low doses of As is highly uncertain because it is based on modeling data collected in populations with a high daily intake of the element. The finding of a slightly increased exposure to arsenic in certain groups of the Belgian general population prompted us to examine whether this had repercussions on the causes of mortality. Method: Statistics of mortality by causes with a possible link to exposure to the element (standardized mortality ratio) were analyzed in groups of the Belgian population previously shown to have been exposed to As from natural (drinking water) and/or industrial (nonferrous metal smelter emissions) sources. Results: A moderately increased absorption of As, leading to a 3- to 4-fold higher urinary excretion (35 mu g/day as compared with 6-10 mu g As/day in nonexposed subjects) did not enhance the mortality by diseases of the nervous system, liver and heart, and cancers. An increase in mortality by lung cancer, however, was observed in men but not women living around zinc smelters and might be related to past occupational exposure and/or smoking habits. Conclusion: A low to moderate level of environmental exposure to inorganic arsenic (0.3 mu g As/m(3) of air; 20-50 mu g As/1 of drinking water) does not seem to affect the causes of mortality, suggesting in particular nonlinearity of the dose-response relationship for arsenic and cancer.