Personal reflections on occupational health in the twentieth century: spiraling to the future.

The history of occupational health in the United States during the twentieth century demonstrates pendular swings, with periods of rapid progress followed by periods of reversal. Happily, the last three decades have witnessed the most impressive gains, with establishment of a near-universal system for regulating conditions in the workplace, legitimization and growth of the occupational health professions, a marked increase in scientific research, most notably epidemiology, and the transfer of knowledge about occupational health to affected workers and the larger US population. Not surprisingly, rates of injury and illness have fallen. However, analysis of these cyclical historic changes suggests that extrinsic factors--broad social currents, changes in health care financing, and societal perceptions of health and disease--have dominated over enhanced scientific knowledge, technologic changes or professional achievements, usually the determinants of medical or public health advances. Practitioners of occupational health are not, and have never been, in a particularly advantageous position to fashion future events in their own field, and the current situation, however encouraging, is likely no exception.