“…Because of its widespread use a relatively large number of workers are exposed to FA. Increased incidences of nasopharyngeal cancer were found in populations occupationally exposed to FA Partanen, 1993;Armstrong et al, 2000;Vaughan et al, 2000;Hildesheim et al, 2001;Coggon et al, 2003;Hauptmann et al, 2004). Animal studies demonstrate that high concentrations of FA can cause irreversible damage to the nasal epithelium of rats and that in some cases rats exposed to these concentrations developed neoplasia (Merk and Speit, 1998).…”