Indoor secondary pollutants from household product emissions in the presence of ozone: A bench-scale chamber study.
Ozone-driven chemistry is a source of indoor secondary pollutants of potential health concern. This study investigates secondary air pollutants formed from reactions between constituents of household products and ozone. Gas-phase product emissions were introduced along with ozone at constant rates into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenoids and oxidation products were measured. Formaldehyde was a predominant oxidation byproduct for the three studied products, with yields for most conditions of 20-30% with respect to ozone consumed. Acetaldehyde, acetone, glycolaldehyde, formic acid, and acetic acid were each also detected for two or three of the products. Immediately upon mixing of reactants, a scanning mobility particle sizer detected particle nucleation events that were followed by a significant degree of secondary particle growth. The production of secondary gaseous pollutants and particles depended primarily on the ozone level and was influenced by other parameters such as the air-exchange rate. Hydroxyl radical concentrations in the range 0.04-200 x 10(5) molecules cm(-3) were determined by an indirect method. OH concentrations were observed to vary strongly with residual ozone level in the chamber, which was in the range 1-25 ppb, as is consistent with expectations from a simplified kinetic model. In a separate chamber study, we exposed the dry residue of two products to ozone and observed the formation of gas-phase and particle-phase secondary oxidation products.
Destaillats
Hugo
H
Indoor Environment Department, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. HDestaillats@lbl.gov
Lunden
Melissa M
MM
Singer
Brett C
BC
Coleman
Beverly K
BK
Hodgson
Alfred T
AT
Weschler
Charles J
CJ
Nazaroff
William W
WW
D000393:Air Pollutants / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006795:Household Products; D010084:Oxidation-Reduction; D010126:Ozone / Q000032:analysis*; D010316:Particle Size; D014835:Volatilization
D000393:Air Pollutants; D010126:Ozone