Chemical changes in thirdhand smoke associated with remediation using an ozone generator

Ozonation is a common remediation approach to eliminate odors from mold, tobacco and fire damage in
buildings. Little information exists to: 1) assess its effectiveness; 2) provide guidance on operation conditions;
and 3) identify potential risks associated with the presence of indoor ozone and ozonation byproducts. The goal
of this study is to evaluate chemical changes in thirdhand smoke (THS) aerosols induced by high levels of ozone,
in comparison with THS aerosols aged under similar conditions in the absence of ozone. Samples representing
different stages of smoke aging in the absence of ozone, including freshly emitted secondhand smoke (SHS) and
THS, were collected inside an 18-m3 room-sized chamber over a period of 42 h after six cigarettes were
consumed. The experiments involved collection and analysis of gas phase species including volatile organic
compounds (VOCs), volatile carbonyls, semivolatile organic compounds (SVOCs), and particulate matter.