GAS PARTICLE PARTITIONING OF ORGANIC-COMPOUNDS TO ENVIRONMENTAL TOBACCO-SMOKE - PARTITION-COEFFICIENT MEASUREMENTS BY DESORPTION AND COMPARISON TO URBAN PARTICULATE MATERIAL/

Certain organic compounds in environmental tobacco smoke (ETS) can cau se respiratory diseases and lung cancers. The behavior and health effe cts of EIS will depend upon how each of these compounds is distributed between the gas and the particulate phases. ETS particles were collec ted on a filter. Semivolatile organic compounds were desorbed from the filter at 20 degrees C using a Row of clean nitrogen at 60% relative humidity. The desorption was followed with time. Volatile, lower molec ular weight compounds were released quickly; less volatile compounds w ere desorbed slowly. A diffusion model was used to estimate gas/partic le partition coefficient (K-p) values. The n-alkane and polycyclic aro matic hydrocarbon (PAH) data agreed with prior measurements for ETS by another method. New data for four nitrogen-containing compounds were obtained. At a given pure compound vapor pressure, PAHs were sorbed mo re strongly than the n-alkanes. The K-p value for nicotine was unusual ly large, probably due to a significant degree of protonation of the n icotine in the EIS phase. For carbazole, however, which cannot be prot onated, K-p was very similar to what would be predicted for a PAH of t he same vapor pressure. After normalization for the fraction of organi c matter in the particulate phase, the ETS data for PAHs agreed well w ith data for PAHs sorbing to urban particulate material (UPM). This is consistent with the interpretation that partitioning to both ETS acid UPM is absorptive in nature.