Evaluation of three types of passive samplers for measuring 1,3-butadiene and benzene at workplaces.

1,3-Butadiene and benzene are common pollutants in both workplace and ambient air and have received attention for their adverse effects on human health. In exposure studies, simple and sensitive personal monitoring methods are preferable. Thermal desorption passive samplers seem optimal for this purpose, although in occupational studies chemical desorption samplers have been used more often. This may be because their utility for monitoring occupational atmospheres has not been thoroughly validated. Therefore, we evaluated thermal desorption passive samplers containing Carbopack X adsorbent from three manufacturers: Perkin Elmer, SKC-Ultra and Radiello. The uptake rates of benzene and 1,3-butadiene by these samplers were determined over 4 h or 8 h in exposure chamber studies at three concentrations likely to be found in occupational air. The samplers were also tested in a field study, at a petroleum refinery. The results were analyzed using multiple linear regression, and intra-class correlation coefficients (ICCs) were calculated to compare uptake rates of the three passive samplers to those of an active sampler. The three samplers had similar and acceptable accuracy (ICC≥0.9) for measuring benzene concentrations in the field environments, but only the Perkin Elmer sampler gave acceptable ICC values (∼0.85) for 1,3-butadiene over a full 8 h working shift in the field test. The results indicate that passive thermal desorption monitors can provide considerably lower limits of detection than chemical desorption monitors after 4-8 h sampling time, even down to environmental background concentrations, enabling comparison with measurements in ambient air.