The overall objective of the research is to develop a new sensitive passive diffusion sampler and couple its use to a miniaturized personal portable video camera system (MPPVCS) for the measurement and assessment of personal exposure to carcinogenic organics in personal air. The proposed research, will: 1. determine the sampling rate under different sampling conditions (different air concentration, sampling duration, temperature, humidity, and face velocity); 2. evaluate the performance of the sampler in side-by-side comparisons with proven active sampling method; 3. evaluate the ability of subjects to successfully wear and manage battery and tape changes; and 4. evaluate the combined effectiveness of the sampler and MPPVCS to capture information about volunteer personal exposures to carcinogenic organics. The new passive sampler consists of a denuder, which is made from 10 0.5-cm (or longer) sections of a multi-capillary gas chromatography (GC) column (900 of 40-micrometer internal diameter). Due to the high value of diffusive area (inner cylindrical surface) to diffusive path length (the radius of the each column), the sampling rate will be about 1000 times higher than the traditional badge or tube-type diffusive samplers. The denuder-type geometry would allow constant sampling rates in a wide range of sampling conditions. Also, the stationary phase of the capillary column allows directly thermal desorption of analytes to an analytical instrument, which avoids dilution of the sample by solvent and increase the sensitivity by a factor of 100. The sampler can be used repeatedly without any regeneration process. During the exposure session, a lightweight, unobtrusive, MPPVCS will be attached to the subject to obtain real time information about proximity to sources of carcinogenic organics and the individual's activities at a given period of time. MPPVCS is less than 1 pound and can be comfortable for individuals to wear. The use of MPPVCS can reduce the costs and burden associated with having a videographer track the individual, reduce the burden associated with having subject completing questionnaires and time/activity diaries, and avoid information loss due to subjects' completion failure and loss of awareness of their activities and the environment. In summary, we propose to develop and validate a sensitive, simple, and cost-effective technique to directly measure personal exposure to carcinogenic organics. Joint use of the new diffusive sampler and MPPVCS would capture both the levels of exposure and the locations of exposure, and possible sources. The combined approach will improve the accuracy of community or residential assessments of personal exposure to carcinogens for prospective epidemiologieal studies, and provide the improved characterization of exposure for risk assessments.
