Short term inhalation exposure to turpentine : toxicokinetics and acute effects in men Agneta

Objectives-This study describes the toxicokinetics, pulmonary function, and subjective ratings of discomfort in volunteers experimentally exposed to turpentine vapour (a mixture of monoterpenes). The results were compared with similar exposure to single monoterpenes to look in the toxicokinetics and acute effects for signs of interactions between the monoterpenes. Methods-Eight male volunteers were exposed to 450 mg/ml turpentine by inhalation (2 h, 50 W) in an exposure chamber. Results-The mean relative uptakes of apinene, /3-pinene, and 3-carene were 62%, 66%, and 68% respectively, of the amount supplied. Between 2% and 5 % of the net uptake was excreted unchanged in the expired air after the end of exposure. The mean blood clearance 21 hours after exposure (CL2lh) of a-pinene, f3-pinene and 3carene, were 0f8, 0 5, and 0 4 l.kg-'.h-1, respectively. The mean half lives (t1,2) of the last phase of a-pinene, f-pinene, and 3-carene averaged 32, 25, and 42 hours, respectively. The t1,2s agreed with previously calculated half lives from single exposures. The total blood clearance CL2lh of 3-carene found in this turpentine study was lower, and CL4h of 3-carene was significantly lower than the values obtained from similar exposure to pure 3-carene. The subjects attending both exposure to turpentine and to pure a-pinene at 450 mg/ml had lower CL4h during the exposure to turpentine, when they experienced more discomfort of the throat or the airways (F = 5-7, P = 0.048) than during exposure to control concentrations. After experimental exposure to turpentine an increase in airway resistance was found that differed significantly from results of exposure to 3-carene at 10 mglm' (P = 0-021) or 450 mg/ml (P = 0.047). Conclusions-Toxicokinetics and acute effects show small, if any, interactions between a-pinene, f3-pinene, and 3carene. The subjects experienced discomDepartment of fort in the throat and airways during Toxicology, National exposure to turpentine and airway resisInstitute of tance was increased after the end of expoS171 84 Solna, Sweden sure. A Falk Filipsson Accepted 26 September 1995 (Occup Environ Med 1996;53:100-105)