Objectives-Among other constituents, fuel oil ash contains vanadium pentoxide, a known respiratory irritant.

Exposure to ambient vanadium pentoxide dust has been shown to produce irritation of the eyes, nose, and throat.

The usefulness of nasal lavage in detecting an inflammatory response to exposure to fuel oil ash among 37 boilermakers and utility workers was investigated.

Methods-A baseline lavage was performed on the morning of the first day back to work after an average of 114 days away from work (range 36 hours to 1737 days).

A lavage was performed after exposure on the morning three days after the baseline lavage.

Exposure to respirable particulate matter of diameter ¾10 mum (PM10) and respirable vanadium dust were estimated with daily work diaries and a personal sampling device for respirable particulates.

These estimates were made for each subject on each workday during the three days between lavages.

For each subject, the adjusted change in polymorphonuclear cells was calculated by dividing the change in polymorphonuclear cell counts by the average of the counts before and after exposure.

Conclusion-A significant increase in polymorphonuclear cells in non-smokers but not smokers was found.

This suggests that in non-smokers, exposure to fuel oil ash is associated with upper airway inflammation manifested as increased polymorphonuclear cell counts.