Region II in northern Chile (population 442 570) experienced a sudden major increase in arsenic water concentrations in 1958 in the main city of Antofagasta, followed by a major reduction in exposure when an arsenic removal plant was installed in 1970. It provides a unique opportunity to study latency effects of exposure to arsenic, and this is the first study with mortality data up to 40 years after exposure reduction.

中文翻译：

---

减少砷暴露40年后的肺癌，膀胱癌和肾脏癌死亡率

智利北部的II区（人口442570）在1958年主要城市安托法加斯塔的砷水浓度突然大幅增加，随后在1970年安装了除砷装置后砷的浓度大大降低。这提供了独特的机会研究砷暴露的潜伏期影响，这是第一项关于减少砷暴露后长达40年的死亡率数据的研究。