Commentary Table 1.

Performance of the Various Models (R²)

City	Pollutant	LUR Model	CNN Model	Combined Model
Toronto	UFP number concentrations UFP size BC	0.71 0.56 0.60	0.66 0.43 0.53	0.73 0.55 0.61
Montreal	UFP number concentrations UFP size BC	0.59 0.48 0.58	0.49 0.41 0.50	0.60 0.49 0.60

BC = black carbon; CNN = convolutional neural network; LUR = land use regression; UFP = ultrafine particles.