2.2. Analytical methods The methods used for collecting and assaying biological specimens from workers with and without masks were as described (Michitsji et al., 1995). Workers wore masks only during periods of high exposure to toluene.
2.2. Analytical methods The methods used for collecting and assaying biological specimens from workers with and without masks were as described (Michitsji et al., 1995). Workers wore masks only during periods of high exposure to toluene.