Measurements of SHS concentrations indicated by PM_2.5 in restaurants and bars in some Chinese cities, µg/m³.

Note: SD standard deviation. a indoor PM2.5 concentrations were reported, not adjusted by outdoor PM2.5 concentrations; b 18 restaurants with interventions on training venue staff how to implement smoke-free policies, and the other 16 venues without any interventions. c 5 restaurants and 15 entertainment venues.