Upper airway inflammation assessed by nasal lavage in compost workers: A relation with bio-aerosol exposure

Exposure to microbial agents in the composting industry may cause work related airway inflammation. Nasal lavage (NAL) has been proposed as a noninvasive method to assess such effects in population studies.

Pre- and post-shift NAL were performed in the workers of a compost plant visited in 1995 (n = 14) and 1996 (n=15), of whom only four participated in both surveys. Total cells, cytokines and other inflammation markers were measured in NAL fluid, and pre-shift levels and post/pre concentration ratios were compared with NAL results obtained in the same periods in 10 and 9 controls, respectively, and with levels of airborne exposure to microbial agents endotoxin and beta(1,3)-glucan as measured in personal air samples.

Job-title specific exposure levels in the first survey ranged from 75 to 527 EU/m(3) for endotoxin and from 0.54 to 4.85 microg/m(3) for beta(1,3)-glucan. In the second survey these values were lower, 29-285 EU/m(3) and 0.36-4.44 microg/m(3), respectively. In the first survey pre-shift NAL concentrations of total cells, MPO, IL-8, NO and albumin were significantly (1.1-4.8 fold) higher in compost workers than in controls. Post/pre ratios for various markers were significantly (1.2-3.2 fold) higher in compost workers in both surveys. NAL cells were mainly neutrophils, while eosinophils were only incidentally observed. A weak relation with exposure was found for pre-shift levels of MPO, uric acid and urea in the first survey.

Occupational exposure of compost workers may cause acute and possibly (sub-)chronic inflammatory reactions in the upper airways, presumably induced by non-allergenic pro-inflammatory agents like endotoxins and beta(1, 3)-glucans.