A field method for sampling toluene in end-exhaled air, as a biomarker of occupational exposure: correlation with other exposure indices.

A sensitive and rapid method for the determination of toluene in exhaled air is described. We have developed a device for direct breath sampling consisting of a sampler inserted into an empty 58 mL glass vial closed by a Teflon rubber septum. The sorbent cartridge functions as a diffusive sampler and employs a Tenax resin (300 mg, 35/50 mesh) to trap volatile organic compounds from the exhaled air. End-exhaled air is collected "in field" by removing the septum from the vial, by forcibly exhaling into the device through a suitable Teflon tube, and then by sealing the bottle quickly. Environmental toluene levels ranged from 13 to 191 mg/m3, while the concentrations of the solvent in alveolar air, in blood and urine ranged from 159 to 3354 ng/L, from 3.6 to 53.5 microg/L, and from 8.7 to 142.4 microg/L respectively. The correlation coefficients (r) of biological measurements towards environmental toluene levels were 0.822, 0.850 and 0.846 for alveolar air, blood and urine samples, respectively. The breath sampler allowed the rapid and non-invasive collection of data on elimination of toluene.