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

Background Exposure to microbial agents in the composting industry may caus e work related airway inflammation. Nasal lavage (NAL) has been proposed as a noninvasive method to assess such effects in population studies. Methods 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 partici pated in both surveys. Total cells, cytokines and other inflammation marker s were measured in NAL fluid, and pre-shift levels and post/pre concentrati on ratios were compared with NAL results obtained in the same periods in 10 and 9 controls, respectively, and with levels of airborne exposure to micr obial agents endotoxin and beta(1,3)-glucan as measured in personal air sam ples. Results 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 mu g/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 mu g/m(3) respectively. In the first survey pre-shift NAL concen trations 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 v arious 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 anal urea in the first survey. Conclusion Occupational exposure of compost workers may cause acute and pos sibly (sub-)chronic inflammatory reactions in the upper airways, presumably induced by non-allergenic pro-inflammatory agents like endotoxins and beta (1,3)-glucans. Am. J. Ind. Med. 37:459-468, 2000. (C) 2000 Wiley-Liss, Inc.