Fig. 4. Measurements and model predictions.

(A) OH, (B) RO₂, (C) HO₂ radical, and (D) possible oxidation product (limonaldehyde, C₁₀H₁₆O₂) concentrations, and (E) size-integrated particle mass concentrations (1.2 to 500 nm) based on monoterpene, O₃, and NO_x concentrations and NO₂ photolysis frequencies. Gray shading corresponds to active periods of mopping and wiping during the cleaning events. OH, HO₂, and RO₂ are compared to measured radical concentrations; OH values are close to the limit of detection and are shown here as 1-hour averages. Error bars shown are 1σ for OH and 2σ for HO₂ and RO₂. In (D), a pseudo first-order rate constant of k = 0.052 s⁻¹ was taken to be representative of the loss to room walls and surfaces. In (E), a constant source rate of 18 μg m⁻³ hour⁻¹ was considered. For the low-O₃ model, O₃ concentrations were divided 16-fold to reach a maximum concentration of 0.6 ppb. For the higher-AER model, the AER was increased to 24 hour⁻¹.