CANCER IN BANANA PLANTATION WORKERS IN COSTA-RICA

Background. Costa Rica has population and disease registries with pote ntial value for epidemiological research. Pesticides have been intensi vely used on banana plantations, for example dibromochloropropane (DBC P). This study was planned to examine the quality of the cancer and ci vil registries and the feasibility of record linkages, and to explore cancer patterns among a highly exposed group. Methods. A retrospective cohort study was carried out. Workers on the payrolls of banana compa nies, as reported to the Social Security System at any time between 19 72 and 1979, were followed up in the cancer registry between 1981 and 1992: 29 565 men and 4892 women for 407 468 person-years. The observed cases of cancer were compared to the expected values, derived from th e national incidence rates. Results. We identified 368 cancer cases, 2 92 among men (standardized incidence ratio [SIR] = 76, 95% confidence interval [CI] 67-84) and 76 among women (SIR = 116, 95% CI :90-142). A mong men increased SIR were observed for melanoma (SIR = 197, 95% CI: 94-362) and penile cancer (SIR = 149, 95% CI:55-324); among women for cervix cancer (SIR = 182, 95% CI : 122-241) and leukaemia (SIR = 274, 95% CI:86-639). Risk estimates for lung cancer were elevated among mal e workers with the longest time of employment. Conclusions. Follow-up was difficult due to deficient identification variables in the cancer registry and to easier identification of the living compared to the de ceased in the civil registry at the end of the observation period. The various systematic errors in this study are likely to produce an unde restimation of the relative risk estimates. This study contributes to improvements of the registries and increases the potential for cancer epidemiology in Costa Rica and other developing countries.