Dynamic behavior of semivolatile organic compounds in indoor air. 2. Nicotine and phenanthrene with carpet and wallboard

The surface interactions of nicotine and phenanthrene with carpet, painted wallboard, and stainless steel were investigated in a room-sized environmen tal test chamber. Adsorption kinetics were tested by flash evaporating a kn own mass of each compound into a sealed 20 m(3) chamber containing one or m ore of the tested sorbents. In each experiment, one or more emissions were performed after the gas-phase concentration had reached an apparent plateau . At the end of each experiment, the chamber was ventilated and resealed to monitor reemission of the compound from the sorbents. Kinetic sorption par ameters were determined by fitting a mass-balance model to the experimental results. The sorption capacity of stainless steel was of similar magnitude for nicotine and phenanthrene. Sorption of nicotine on carpet and wallboar d was much stronger, with equilibrium partitioning values 2-3 orders of mag nitude higher. The sorption capacities of phenanthrene on carpet and wallbo ard were smaller, approximately 10-20% of the stainless steel values. The r ates of uptake are of similar magnitude for all sorbate-sorbent pairs and a re consistent with the limit imposed by gas-phase boundary/layer mass trans port. The rates of desorption are much faster for phenanthrene than for nic otine. Model simulations predict average nicotine levels in a typical smoki ng residence that are consistent with published data.