Objective To analyze the annual dynamic change characteristics of the mass concentrations of formaldehyde, benzene, toluene, and xylene in the air of hotel guest rooms in Liaocheng, China, and assess their potential health risks to hotel room employees, so as to provide a scientific basis for strengthening health management for hotels.

Methods From 2016 to 2021, 18 hotels were randomly selected in Liaocheng in every year to measure the mass concentrations of gaseous formaldehyde, benzene, toluene, and xylene in hotel guest rooms, and a questionnaire survey was conducted for the working patterns and other information of hotel guest room employees. Air samples in the guest rooms were collected for laboratory testing according to the Examination Method for Public Places-Part 2: Chemical Pollutants (GB/T 18204.2-2014). Using the health risk assessment model recommended by the United States Environmental Protection Agency (USEPA) and the method from the Technical Guide for Environmental Health Risk Assessment of Chemical Exposure (WS/T 777-2021), the carcinogenic and chronic non-carcinogenic risks of the four gaseous pollutants in guest rooms through inhalation were evaluated based on the actual exposure time of guest room employees.

Results The overall unqualified rates of formaldehyde, benzene, toluene, and xylene in Liaocheng hotels from 2016 to 2021 were 15.4%, 0.3%, 1.1%, and 1.2%, respectively. Their median mass concentrations were all lower than those of the national standard limits. The concentrations of the four pollutants showed generally downward trends from 2016 to 2021, with statistical significance (all P < 0.001). Formaldehyde showed the greatest carcinogenic risk (CR) and non-carcinogenic risk (hazard quotient, HQ), with 2.5% (17/663) and 60.0% (398/663) above the potential risk levels of 10^-4 and 1, respectively, and the maximum values reached 9.16×10^-4 and 16.72, respectively. Benzene had certain carcinogenic and non-carcinogenic risks, with the maximum values of 5.49×10^-4 and 3.29, respectively. The HQ of toluene was less than 1. The maximum HQ of xylene was 2.30, indicating a certain non-carcinogenic risk.

Conclusion The mass concentrations of formaldehyde and benzene series chemicals in the air of the guest rooms in Liaocheng hotel exist unqualified samples, both with certain degrees of potential health risks to guest room employees in some monitoring points.