Abstract: ObjectiveTo study the chronic non-cancer health risk and cancer risk from formaldehyde in indoor air of public places.MethodsFrom 2014 to 2015, formaldehyde in indoor air was monitored in public places (hotels, malls, dance halls, beauty salons, cinemas, hospital and station waiting rooms) in Longgang District, Shenzhen City and its health risks to employees were assessed using approaches to chronic non-cancer risk and cancer risk assessments of EPA.ResultsA total of 185 public places were monitored, including 53 rooms of the hotels, 46 shopping malls, 43 dance halls, 15 beauty salons, 10 cinemas, 13 hospital waiting rooms, and 5 station waiting rooms. The average concentrations of formaldehyde in air of cinemas, hospital waiting rooms, hotels, dance halls, shopping malls, beauty salons, and station waiting rooms were 0.08, 0.03, 0.06, 0.07, 0.06, 0.05, and 0.05 mg/m3, respectively. Risk assessment results showed that the chronic non-cancer risk of formaldehyde to the employees existed in air of all public places (HQ>1), except the hospital waiting rooms; the cancer risk of formaldehyde to the employees existed in all public place (>1×10-6), where the highest one was in the cinemas (1.02×10-4).ConclusionThe chronic non-cancer risk and cancer risk of formaldehyde in the indoor air of public places to the employees were high in Longgang district, Shenzhen City.