过去，流行病学家对一些较常见疾病及其主要危险因素如肺癌与吸烟的关系进行了大量的研究，对一些罕见病及其不寻常的暴露因素，例如石棉与肺间皮瘤的关系也进行了研究。虽然已经查明了一些比较明显的相关性，但对一些不常见的疾病或肿瘤的罕见的暴露方式并不清楚。当前，一个 In the past, epidemiologists have conducted extensive studies on the relationship between some of the more common diseases and their major risk factors, such as lung cancer and smoking. For some rare diseases and their unusual exposure factors such as asbestosis and mesothelioma Were studied. Although some obvious correlations have been identified, the rare pattern of exposure to some unusual disease or tumor is not clear. Currently, one