Respiratory effects of bioaerosols: Exposure–response study among salmon-processing workers
Objectives The aim of the study was to determine exposure–response relationships in salmon-processing workers.
Methods Cross-shift FEV1, acute respiratory symptoms, and exposure to total protein, parvalbumin and endotoxin were main variables measured during one workweek. Exposure–response relationships were analyzed by Generalized Estimation Equations of cross-week data and by multiple regressions of day-to-day data.
Results Exposure levels were higher in those workers who reported use of water hose. GEE showed negative coefficients for interaction between TP exposure and time (days) on cross-week change of FEV1. Multiple regressions showed significant associations between TP levels and cross-shift change of FEV1 and symptoms (cough, chest tightness) only for Monday shifts.
Conclusions A tolerance effect during the course of a workweek is suggested. Use of water hose is a risk process with regard to the liberation of measured components of bioaerosols.