Wood smoke: measurement of the mutagenic activities of its gas- and

Environ. Sci. Technol. 1986, 20, 493-501

Wood Smoke: Measurement of the Mutagenic Activities of Its Gas- and Particulat e-P hase Photooxidation Products Tadeusz E. Kleindienst,” Paul B. Shepson, and Edward 0. Edney

Northrop Services, 1nc.-Environmental

Sciences, Research Triangle Park, North Carolina 27709

Larry D. Claxton

Health Effects Research Laboratory, US. Environmental Protection Agency, Research Triangle Park, North Carolina 27711 Larry T. Cupitt

Atmospheric Sciences Research Laboratory, U S . Environmental Protection Agency, Research Triangle Park, North Carolina 277 1 1 Dilute mixtures of wood combustion emissions (with and without additional NO,) were irradiated in a 22.7-m3 Teflon smog chamber. The effluent was tested for mutagenic activity by exposing Salmonella typhimurium, strains TAlOO and TA98, to the filtered gas-phase components. The particulate matter was tested by using the plate incorporation procedure. Without added NO,, irradiated dilute wood smoke showed a measurable increase in mutagenic activity for gas-phase products only. Additional NO, was added in other irradiations to enhance the formation of gas- and particulate-phase products. Although only lower and upper limits were obtainable, the gas-phase products showed considerably more activity (1.1-8.2 revertants/pg) in TAlOO exposures than did the particulate product extracts. With TA98 the activities of both phases were comparable on a mass basis. Since the total quantity of gas-phase components was greater than the particulate-phase components, the mutagenic activity on a volume basis was greater for the gas phase.

Introduction Recently, there has been increased concern that human exposure to wood stove and fireplace emissions may provide a public health concern. In a study of the Denver “brown cloud”, Wolff et al. (1)determined that approximately one-third of the organic fine particulate matter (