A. Sampling Design and Passive Samplers
Sampling Design
Half of the households deployed indoor and outdoor passive samplers for volatile organic compounds (VOCs) and nitrogen Dioxide (NO2) for 7 days (Figure A.1). Remaining homes deployed indoor and outdoor passive NO2 for 2 days and (co-located) samplers for polycyclic aromatic hydrocarbons (PAH) for 1 and 2 days.
Figure A.1 Main Sampling Groups: 7 Day VOC and NO2 versus 1 and 2 Day PAH and 2 Day NO2 Households
There were 12 slightly different versions of equipment and instructions in this study based on the two major sampling groups and deployment of indoor and outdoor duplicates (Figure A.2).
Figure A.2 Detailed Depiction of Sampling Groups Including Duplicate and Non-Duplicate Homes
Passive sampling devices and chemical analyses
Volatile Organic Compounds were passively collected for 7 days prior to the clinical visit using Supelco Carbopack B adsorbent (unwashed 40/60 mesh) packed in Perkin-Elmer stainless steel tubes (Supelco, Bellefonte, PA). VOC tubes were analyzed using thermal desorption/ gas chromatography/ mass spectrometry (desorption/ GC/ MS) techniques. The measurements reflect a 7 day average concentration for 22 VOC species. VOC tubes and analyses were provided by Harvard School of Public Health. The VOC analysis methodologies have been described in McClenny et al., 2006.
Nitrogen Dioxide was sampled using Ogawa passive sampling devices (Ogawa & Co., Pompano Beach, FL). Integrated NO2 sampling was conducted for 7 days in 7 day VOC/NO2 homes and for 2 days in 1,2 day PAH/NO2 homes to facilitate inter-comparison between the 2 sampling groups. NO2 badges and analyses were provided by the Harvard School of Public Health. Evaluation of NO2 monitoring using Ogawa passive samplers has been described elsewhere (Mukerjee et al., 2004; Sather et al., 2006; Sather et al., 2007).
Polycyclic Aromatic Hydrocarbons were passively collected using Fan-Lioy Passive PAH Samplers (FL-PPS) (Fan et al., 2006). A total of 4 samples were collected for each home (excluding duplicates). Both indoor and outdoor samples were collected for 1 and 2 day sampling periods prior to the clinical visit; 1 and 2 day samplers were co-located. The samples reflect 1 and 2 day average concentrations for 8 PAH species. PAH samplers and analyses were provided by the Environmental and Occupational Health Sciences Institute (EOHSI).
With the exception of the FL-PPS monitors, all of the passive samplers used in this study were previously evaluated through other EPA-sponsored field studies in the Detroit area (Williams et al., 2005; Mukerjee et al., 2007; Smith et al., 2006; Williams and Wheeler, 2007).
References:
Fan Z, Jung KH, Lioy PJ. Development of a Passive Sampler to Measure Personal Exposure to Gaseous PAHs in Community Settings. Environmental Science and Technology 2006;40(19):6051-6057.
McClennyWA, Jacumin HH Jr, Oliver KD, Daughtrey EH Jr, Whitaker DA. Comparison of 24 h averaged VOC monitoring results for residential indoor and outdoor air using Carbopack X-filled diffusive samplers and active sampling—a pilot study. Journal of Environmental Monitoring 2006; 8(2):263-269.
Mukerjee S, Smith LA, Norris GA, Morandi MT, Gonzales M, Noble CA, Neas LM, Özkaynak AH. Field method comparison between passive air samplers and continuous monitors for VOCs and NO2 in El Paso, Texas. Journal of the Air & Waste Management Association 2004; 54(3):307-319.
Sather ME, Slonecker ET, Kronmiller KG, Williams DD, Daughtrey H, Mathew J. Evaluation of short-term Ogawa passive, photolytic, and federal reference method sampling devices for nitrogen oxides in El Paso and Houston, Texas. The Journal of Environmental Monitoring 2006; 8(5):558-563.
Sather ME, Slonecker ET, Mathew J, Daughtrey H, Williams DD. Evaluation of ogawa passive sampling devices as an alternative measurement method for the nitrogen dioxide annual standard in El Paso, Texas. Environmental Monitoring and Assessment 2007; 124(1-3):211-221.