The association of occupational asbestos dust exposure and laryngeal carcinoma.

Controversy exists as to whether occupational asbestos dust exposure is responsible, or at least partially responsible, for the development of laryngeal carcinoma. The aim of this study is to present the current scientific knowledge on this subject based on a comprehensive literature research and to critically review the epidemiological investigations published. The results of 31 cohort studies and 24 case-control studies, and the conclusions in 11 more recent reviews are contradictory. In most studies there was no statistically significant indication of a casual relationship. It is noteworthy that an increased risk of laryngeal carcinoma among persons exposed to asbestos dust was observed mostly in older studies in which smoking habits and/or alcohol consumption as the most important nonoccupational risk factors were usually not taken into account. In addition, since most of the calculated positive associations are very weak, no reliable conclusion can be reached. While there may be a causal relationship between occupational exposure to asbestos dust and the occurrence of laryngeal carcinoma, this cannot be regarded as certain on the basis of the evidence reviewed.