Longkankerrisico en blootstelling aan cadmium via het milieu: antwoord op de kritiek met toetsing van de causaliteit

Abstract

AbstractLung cancer and environmental exposure tocadmium: a reply to the critique andevaluation of causalityWe investigated whether the risk of lung cancer isrelated to environmental exposure to cadmium. From1985-1989 we randomly recruited 994 subjects fromareas with low and high exposure to cadmium. Wemeasured their 24-hour urinary cadmium excre-tion, an index of lifelong exposure, as well as thecadmium concentration in the soil of their kitchengardens.The cadmium concentration in the soil ranged from0.8 to 17.0 mg/kg. The 24-hour urinary cadmiumexcretion averaged 12.3 nmol in residents of the pol-luted area, compared to 7.7 nmol in the referencearea (p < 0.0001). During 17.2 years (median) offollow-up, 53 fatal and 20 non-fatal cancers occurred,of which 18 and 1 were lung cancers (outcomeupdated until 31 October 2004). The hazard ratiosfor lung cancer adjusted for sex, age and smoking,were 1.70 (1.13-2.57; p = 0.011) for a doubling ofthe urinary cadmium excretion, 4.17 (1.21-14.4;p=0.024) for residing in the high versus low expo-sure area, and 1.57 (1.11-2.24; p = 0.012) for a dou-bling of the cadmium concentration in the soil.In the first part of the present overview, we sum-marized our findings which were previously pub-lished in English. Next, we report the results of addi-tional analyses, which we executed in response tothe critical comments on our primary study. We alsoverified our primary and additional study resultsaccording to the Bradford-Hill criteria to detect acausal association.Finally, we reviewed possible mechanisms under-lying the association between lung cancer andexposure to cadmium as well as the preventivemeasures which can be implemented in areasenvironmentally polluted by cadmium.