Effects on respiratory morbidity of occupational exposure to carbon black: a review.

Carbon black is a substance of world importance, both in terms of tonnage production and its special ability to strengthen rubber. Its carbonaceous nature and respirable size give rise to concern regarding its effect on respiratory morbidity for those involved in its manufacture and use. A number of studies have used chest radiographs, spirometry and respiratory symptoms as means of assessing the various populations, but almost all of the studies have either methodological shortcomings or fail to report the necessary detail. However, exposure-related effects are evident in those populations studied in terms of small opacities, reduction in forced expiratory volume in 1 s and forced mid-expiratory flow, and symptoms of chronic bronchitis.