Controlled short‐time terpene exposure induces an increase of the macrophages and the mast cells in bronchoalveolar lavage fluid

Eight healthy nonsmoking volunteers underwent terpene exposure (450 mg/m3 air) on 4 different occasions within a 2 week period. Total exposure time was 12 hours. Before and after the sequences of exposure, bronchoalveolar lavage was performed. Twenty hours after the exposure there was a significant (p < 0.05) increase of the alveolar cell concentration (median pre-exposure value 76 x 10(6) cells/L, post-exposure value 126 x 10(6) cells/L), predominantly due to an increment of the macrophages (from 72 x 10(6) cells/L to 121 x 10(6) cells/L). The mast cells also increased from 1/10 to 5/10 visual fields. No elevated concentrations of albumin, fibronectin, hyaluronan (hyaluronic acid), and tryptase were observed. We conclude that terpene exposure, in a concentration regarded as moderate, induces an acute alveolar cellular reaction in healthy subjects.