Occupational exposures to asbestos, polycyclic aromatic hydrocarbons and solvents, and cancers of the oral cavity and pharynx: a quantitative literature review

Int Arch Occup Environ Health. 2012 May;85(4):341-51. doi: 10.1007/s00420-011-0683-y. Epub 2011 Jul 22.


Purpose: The role of occupational risk factors in oral and pharyngeal cancer is not well known and is possibly underestimated. This quantitative review summarizes epidemiological findings on exposure to asbestos, polycyclic aromatic hydrocarbons and solvents, and cancers of the oral cavity and pharynx.

Methods: A systematic literature search was performed. We analyzed 63 publications: 8 from case-control studies and 55 from cohort studies. For agents with at least five available studies with homogenous exposure, a series of meta-analyses was conducted to provide quantitative pooled estimates of risks, using random effect models.

Results: Exposure to asbestos (meta-RR 1.25; 95% CI 1.10-1.42) and to polycyclic aromatic hydrocarbons (meta-RR 1.14; 95% CI 1.02-1.28) was found to be associated with oral and pharyngeal cancer risk. On the other hand, no association was found with exposure to solvents in general (meta-RR 0.98; 95% CI 0.77-1.23) but the strong heterogeneity between studies suggested differences in exposures. The small number of studies with homogeneous exposure did not allow meta-analyses for specific solvents.

Conclusions: Future investigations should overcome common weaknesses of past studies, in terms of sample size, characterization of exposure, and classification of cancer sites.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Asbestos / adverse effects*
  • Humans
  • Mouth Neoplasms / chemically induced*
  • Occupational Diseases / chemically induced*
  • Occupational Exposure / adverse effects*
  • Pharyngeal Neoplasms / chemically induced*
  • Polycyclic Aromatic Hydrocarbons / adverse effects*
  • Solvents / adverse effects*


  • Polycyclic Aromatic Hydrocarbons
  • Solvents
  • Asbestos