Objective: Previous studies have shown that waiters have a high risk of developing cancers of the buccal cavity and pharynx, but nasopharyngeal cancer (NPC) has not been specifically studied. This study was carried out to investigate whether waiters/waitresses in Chinese restaurants have an increased risk of dying from NPC.
Methods: A mortality odds ratio study was used to estimate the relative risk of dying from NPC for waiters/waitresses working in Chinese restaurants in Hong Kong during the period 1986-1995, using the general population as the external comparison group and deceased kitchen workers as an internal comparison group. Cases were deaths from NPC and the controls were deaths from the selected sets of reference causes.
Results: Seventeen deaths from NPC were identified among 415 deceased waiters and four NPC deaths occurred among 140 deceased waitresses. The adjusted mortality odds ratio (aMOR) for NPC was increased among waiters, being 3.02 (95% CI 1.82-5.00) and 2.61 (95% CI 1.02-6.69) in the external and internal comparisons, respectively. For waitresses, the aMOR was 4.58 (95% CI 1.63-12.86) in the external comparison. Analysis by duration of union membership suggested a dose-response relationship.
Conclusions: An increased risk of dying from NPC was observed among waiters/waitresses and could not be fully explained by bias or confounding factors. Possible risk factors related to poor indoor air quality in the service areas of Chinese restaurants in Hong Kong should be further investigated.