AbstractThe release of TCDD in Seveso and the exposure of the people living in the contaminated territory has confronted the medical community responsible for the health surveillance of this population with a choice of techniques to be used for the task. Several methods of medical survey have been adopted: demographic and epidemiologic studies, prevalence surveys, retrospective and prospective cohort studies, cross‐sectional and case‐control studies, and short term tests of human monitoring. The techniques had to conform to the morbidity patterns to be examined; to the confounding variables to be considered; to the underlying disease conditions of the population; to the baseline data which were not always available or were insufficient; to the problem of non‐compliance; to the provision of appropriate control groups. Each technique contributed a different level of information in respect to the causal relationship with the suspected agent. None of the techniques could escape the limitations of the clinical toxicology studies where the number of exposed people entering the study is imposed by circumstances beyond the control of the investigators, and exposure is often poorly defined. At present, five years after the accident, chloracne has been the only clinical sign which can be causally related to a TCDD exposure in S
展开▼
