MERI

DEVELOPMENT AND APPLICATION OF A SENSITIVE PASSIVE SAMPLING METHODOLOGY FOR THE MEASUREMENT AND ASSESSMENT OF PERSONAL EXPOSURE TO GASEOUS PAH'S

Abstract: Personal monitoring is the most direct approach to determine personal contact with carcinogenic agents. However, due to the trace levels of polycyclic aromatic hydrocarbons (PAHs) in air and the limited sampling rate of passive samplers, there are few applications of passive samplers for measuring airborne PAHs. A sensitive, simple, and cost-effective passive sampling methodology was developed to quantify personal exposure to gaseous polycyclic aromatic hydrocarbons (PAHs) in community settings. A passive PAH sampler (PPS) was constructed from 320 sections of 1 cm long SPB-5 GC columns (0.75-mm ID and 7-┬Ám film thickness), like a mini-honeycomb denuder. Given the unique feature of the GC column stationary phase, gaseous PAHs were collected on the inner surfaces of the columns by molecular diffusion and thermally desorbed to GC/MS for analysis, which avoided the necessity for time-consuming sample preparation and allows for low detection limits, since entire samples can be used for gas chromatography analysis. Thermal desorption method was optimized for analysis of the semi volatile organic compounds (SVOCs) since general thermal desorption system was designed for analysis of the volatile organic compounds (VOCs). The PPS performance was evaluated in the laboratory using a test atmosphere containing seven PAHs for a range of face velocity, temperature, relative humidity, PAH concentration, and sampling duration. The results showed that there was no significant impact of simulated air concentration, face velocity, and temperature on the sampling rate of the sampler for an 8-hour sampling period. It was also evaluated in the field by side-by-side comparison with a conventional active PAH sampling method. The evaluation results showed that the PPS was a valid passive sampler for the measurement of gaseous PAHs, except naphthalene, in personal air for a sampling duration of 8 to 48 hours, but 24-hour sampling time was required for detection of most PAHs in community settings. The joint use of time/activity diaries with the direct measurement of personal PAHs by the PPS enhanced the accuracy of the assessment of personal exposure to PAHs.