A field comparison of inhalable and thoracic size selective sampling techniques

We measured inhalable, thoracic, and so-called "total" wood dust exposure i n British Columbia lumber mill workers, Particle-size selective sampling wa s conducted using the GSP and Seven hole inhalable samplers, the PERI thora cic sampler and the 37-mm closed-face cassette "total" sampler. All measure ments were full-shift personal samples? obtained from randomly selected wor kers, We obtained intersampler comparison data for the following: pairs of instruments: GSP and 37-mm sampler; GSP and seven-hole sampler (SHS); and P ERI and 37-mm sampler. The intersampler measurement ratios were estimated a s: GSP/37-mm sampler=4.2; GSP/SHS= 1.7; and PEM/37-mm sampler = 1.6, The GS P/37-mm sampler ratio is consistent with previously reported findings, whil e PEM/37-mm sampler and GSP/SHS ratios were both larger than expected, We f ound that in all comparisons, the measurement ratio hail significant variab ility that was greatest at low ambient dust concentrations, Although it was not possible to attribute the source of the variability to specific sample r types, we concluded that the GSP sampler might be susceptible to "project ile" particles not normally aspirated, and may be vulnerable to direct aspi ration of dust from accidentally contacted surfaces, The PERI was designed for environmental monitoring, and it is possible that it is unsuited to the higher particulate concentrations found in some occupational settings. Dis parities among inhalable sampling techniques such as that between GSP and S HS should be investigated further in light of the proposed adoption of the inhalable method as an industrial standard, (C) 1999 British Occupational H ygiene Society. Published by Elsevier Science Ltd. AU rights reserved.