Dose-response relations for occupational exposure to arsenic and cadmium

摘要

The dose-response relationship between arsenic exposure and lung cancer in occupationally exposed workers and between occupational cadmium exposure and various kidney effects was studied. A cohort of 3916 Swedish smelter workers showed an increased over-all mortality as well as excess relative risks of deaths due to cancer of the lung and stomach, cardiovascular and cerebrovascular disease, compared with the Swedish general population, When a regional reference population was used, only lung cancer mortality remained significantly elevated. A positive dose-response relation was found between cumulative arsenic exposure and lung cancer risk, the relative risk among the highest exposed workers being more than ten-fold (SMR=1137) (95% confidence interval=588-1986). The dose-response relation was further strengthened when smoking data was added in a nested case-referent study within the smelter cohort. The interaction between arsenic and smoking appeared to be more than additive, but less than multiplicative. Cadmium in the blood has been considered to reflect recent exposure. It was shown in a group of cadmium copper alloy workers that the decay of cadmium in blood followed a two-exponential model. Blood cadmium can thus also be regarded as an estimate of the body burden after cessation of exposure. The use of blood cadmium as a dose estimate was further explored in a group of 440 cadmium exposed battery workers. A clear dose-response relation was found between cumulative blood cadmium and tubular proteinuria. It is recognised that highly exposed workers may develop a glomerula dysfunction in addition to their tubular damage. A questionnaire including questions of the history of kidney stones was sent to the living individuals and the next of kin to the deceased workers in a cohort of 902 cadmium exposed battery workers. There was in increased incidence of renal stones among the medium and highly exposed workers.