A field study to assess the long-term sampling feasibility of evacuated canisters and the development of a mathematical model to analyze potential sampling bias.
Small, evacuated canisters (300 mL) equipped with a unique capillary flow controller were used to evaluate airborne concentrations of Stoddard solvent. The physical characteristics of the flow controller permitted the collection of air samples for a time period of 40 hours (5 consecutive work days). Long-term sampling (greater than 8 hours) is rarely performed in industrial hygiene due to limitations in current air sampling technology but may provide valuable information in characterizing worker cumulative exposures for some processes. A field study was performed to evaluate the feasibility of collecting a 40-hour area sample using the small canisters. Six canister samplers were used as area monitors to evaluate a cleaning operation for an entire workweek. For comparison, 30 diffusive badges (6 per day) were simultaneously used to monitor the same process. No statistical difference was found between the time-weighted average for the two sampling methods (p > 0.05). In addition, the canister samples integrate airborne concentrations for an entire workweek and therefore peak concentrations are not explicitly observed. Thus, an examination of peak exposures using simulated concentrations was conducted. A mathematical model was developed to determine whether a significant sampling bias was associated with long-term canister sampling when peak concentrations are present. The maximum possible bias was determined to be less than 9% for peak amplitudes having 10 times the background concentration and well below that for smaller amplitudes. Long-term sampling with the small, evacuated canisters was found to provide results comparable to sorbent sampling methods but with the added benefit of a significantly increased sampling time.
Rossner
Alan
A
Center for the Environment and Biology Department, Clarkson University, Potsdam, NY 13699, USA. rossner@clarkson.edu
Wick
David P
DP
D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis*; D000535:Aluminum; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D005240:Feasibility Studies; D005373:Film Dosimetry; D006801:Humans; D006838:Hydrocarbons / Q000032:analysis*; D019570:Inhalation Exposure / Q000032:analysis*; D008669:Metallurgy; D008875:Middle Aged; D008962:Models, Theoretical; D016273:Occupational Exposure / Q000032:analysis*; D012494:Sampling Studies; D015983:Selection Bias; D020711:Threshold Limit Values; D013995:Time
D000395:Air Pollutants, Occupational; D006838:Hydrocarbons; C012559:Stoddard solvent; D000535:Aluminum