Risk of mortality, cancer incidence, and stroke in a population potentially exposed to cadmium

Objectives-To follow up mortality and cancer incidence in a cohort potentia lly exposed to cadmium and to perform a geographical (ecological) analysis to further assess the health effects of potential exposure to cadmium. Methods-The English village of Shipham has very high concentrations of cadm ium in the soil. A previous cohort study of residents of Shipham in 1939 sh owed overall mortality below that expected, but a 40% excess of mortality f rom stroke. This study extends the follow ups of the cohort for mortality t o 1997, and includes an analysis of cancer incidence from 1971 to 1992, and a geographical study of mortality and cancer incidence. Standardised morta lity and incidence ratios (SMRs and SIRs) were estimated with regional refe rence rates, Comparisons were made with the nearby village of Hutton. Results-All cause cohort mortality was lower than expected in both villages , although there was excess cancer incidence in both Shipham (SIR 167, 95% confidence interval (95% CI) 106 to 250) and Hutton (SIR 167, 95% CI 105 to 253). There was an excess of mortality from hypertension, cerebrovascular disease, and nephritis and nephrosis, of borderline significance, in Shipha m (SMR 128, 95% CI 99 to 162). In the geographical study, all cause mortali ty in Shipham was also lower than expected (SMR 84, 95% CI 71 to 100). Ther e was an excess in genitourinary cancers in both Shipham (SIR 160, 95% CI 1 07 to 239) and Hutton (SIR 153, 95% CI 122 to 192). Conclusion-No clear evidence of health effects from possible exposure to ca dmium in Shipham was found despite the extremely high concentrations of cad mium in the soil.