To understand and assess the health risks of five common chemical pollutants, formaldehyde, ammonia, benzene, toluene and xylene, in indoor air of public places in Xining City, and to provide technical support for environmental health management of public places in Xining City.

From 2020 to 2022, monitoring sites were set up in the western and central districts of Xining City to monitor the data of common chemical pollutants in hotels and barbershops, and conduct health risk assessment of chemical pollutants according to the Technical Guide for Environmental Health Risk Assessment of Chemical Substances (WS/T 777-2021).

From 2020 to 2022, there were 238 monitoring points in the hotel, only 2 formaldehyde monitoring points exceeded the standard. The total qualified rate of formaldehyde in the hotel was 99.16%, and the total qualified rate of benzene, toluene and xylene in the hotel was 100%. There are 47 monitoring points in barbershop, and the total pass rate of formaldehyde, benzene, toluene, xylene and ammonia at each monitoring point is 100%. The concentration of benzene in indoor air in barbershop (0.001 mg/m³) was lower than that in hotel (0.002 mg/m³), and the difference was statistically significant (Z=-2.708, P<0.05). Among 47 monitoring points in barbershop, 23 monitoring points had a risk between 10^-4 and 10^-6, accounting for 48.9%, and the rest had a risk value higher than 10^-4; Among 238 monitoring points in hotel, 154 monitoring points had a risk between 10^-4 and 10^-6, accounting for 64.7%, and the rest had a risk value higher than 10^-4; There were 34 monitoring sites in barbershop with risk less than 10^-6, accounting for 72.3%, and 138 monitoring sites in hotel with risk less than 10^-6, accounting for 58%. The risk values of P₇₅ and maximum concentration of both sites were greater than 10^-6. Hotel formaldehyde has 150 monitoring points HQ>1, accounting for 63%, the maximum risk value is 3.6; There were two monitoring points for benzene with HQ>1, accounting for 0.8%, and the maximum risk was 1.08. All HQ of toluene and xylene are less than 1. There were 31 monitoring points for formaldehyde in barbershop, HQ>1, accounting for 66%, and the highest risk value was 3.72. HQ of other pollutants is less than 1.

The concentration of five chemical pollutants in the air of public places in Xining City from 2020 to 2022 basically meets the requirements of the national standard, but the carcinogenic risk and non-carcinogenic risk caused by formaldehyde and benzene should be paid attention to.