Cleaning activities can affect indoor air composition long after the cleaning is completed. Utilizing data from detailed observational monitoring campaigns, conducted over 21 weeks, we explore the influence of cleaning activities in two normally occupied, single-family houses. To study emissions and chemistry, we quantified more than 200 volatile organic compounds (VOCs) using a proton-transfer reaction time-of-flight mass spectrometer and 52 semivolatile organic compounds (SVOCs) using a semivolatile thermal-desorption gas chromatograph. During regular professional home cleaning, we observed postcleaning concentration enhancements in ∼60% of measured VOCs and ∼80% of measured SVOCs. Most of these concentration enhancements were not clearly linked to either primary emission from cleaning products or secondary formation through reactive chemistry. Instead, we infer that shifts in the sorptive properties of indoor surfaces account for most of these observations. Cleaning-associated enhancements mostly ebbed within a few hours, with some VOCs and lower-volatility SVOCs persisting more than 5 h, longer than would be expected for removal of inert species by ventilation. The use of carpet cleaner was associated with direct emission of 2-butoxyethanol, which persisted at elevated concentrations for days after the initial event. Home cleaning is potentially relevant for the health of professional cleaners and residents.
Keywords: air pollution; exposure; particles; sorption; source characterization.