Some reflections on the limits of exposure to dangerous airborne substances

The author reviews the diverse methods used to establish safe limits of exposure to industrial substances that risk overtaxing man's natural defenses and impairing his health. These are a compromise between scientific rigour and administrative practicability, and he proposes a statistical method that would obviate the arbitrariness they often entail. He then reviews the special case of carcinogens, discusses the technical and economic feasibility of keeping exposure within safe limits and explains why environmental standards for air pollutants must be stricter than exposure limits at work. He concludes by outlining a system for screening new chemicals for harmful effects before their introduction into industry