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Objective To analyze the basic hygiene status and main health hazard factors of public places in Hainan Province, so as to provide technical support for promoting health management of public places. Methods The health hazard factors of 200 public places in Hainan Province were monitored in 2022, and the results were statistically analyzed. Results A total of 2 339 samples from public places in Hainan Province were monitored, and the overall qualified rate was 83.9%. There were significant differences in the qualified rates of samples from different types of places (χ#178;=120.63, P < 0.05). Among them, the qualified rates of swimming pools (halls) and hotels (hotels) were relatively low, which were 65.8% and 76.3%, respectively, while the overall qualified rates of the other five types of places were between 85.7% and 96.5%. The main unqualified indexes of indoor air in hotels were formaldehyde, the total number of bacteria, PM10, and PM25. The main unqualified indexes of indoor air in barber shops and beauty shops were ammonia and PM10. The main unqualified index of indoor air in shopping malls (supermarkets) was the total number of bacteria. The total number of bacteria detected in all kinds of public goods and appliances in 6 types of public places exceeded the limit. The unqualified rate of pH value of towels in hotels, beauty shops, and barber shops was 43.2%, 13.6% and 11.4%, respectively. The main unqualified indexes of swimming pool were the pH value of swimming pool water, urea and oxidation-reduction potential, and the unqualified rate of oxidation-reduction potential was 29.6%. Conclusion The hygienic condition of public places in Hainan Province still needs to be improved in 2022. It is suggested that the relevant departments further strengthen the supervision and monitoring of the total number of bacteria, ammonia, PM10, PM25 and formaldehyde in indoor air, the total number of bacteria, coliform group and pH value of towels for public goods, and the redox potential, urea and pH value of swimming pool water. [ABSTRACT FROM AUTHOR]

The aromatic odor of Plectranthus hadiensis var. tomentosus has been found to have the potential to improve physical and mental health of people in indoor environment, but its effectivess is reduced for that the release of volatile organic compounds from plants is susceptible to indoor environmental changes. The purpose of this study was to investigate the response of volatile organic compounds released by P. hadiensis var. tomentosus to common indoor environmental changes, and to provide a scientific basis for its efficient and sustainable application in building a comfortable pro-biotic environment to improve the physical and mental health of indoor personnel. Thus, the effects of four typical indoor environmental factors, such as air temperature, air relative humidity, CO2 concentration and light variation, on the release of volatile organic compounds from P. hadiensis var. tomentosus were investigated in this study. And the dynamic headspace and gas chromatography-mass spectrometry techniques were used to analyze the volatile organic compounds in different indoor environments with an environmental control device based on mixed-level orthogonal array design. The results were as follows:(1)Among the four typical indoor environmental factors of air temperature, air relative humidity, CO2 concentration and light condition, CO2 concentration and air temperature had greater effects on the release of volatile organic compounds from P. hadiensis var. tomentosus, while the effects of air relative humidity and light were weak.(2)For P. hadiensis var. tomentosus cultivated under normal photoperiod, an environmental condition with CO2 concentration of 500 μmol·mol-1, air temperature of 25 ℃ and air relative humidity of 60% was the most suitable for releasing volatile organic compounds from P. hadiensis var. tomentosus in the absence of light. Under this environmental condition, the total amount of volatile organic compounds released by P. hadiensis var. tomentosus was 86.23 μg·L-1·kg-1, and the content of biological active components with potentials for the positive intervention of physical and mental health was 78.03 μg·L-1·kg-1. In summary, the results suggest that when the aroma plant P. hadiensis var. tomentosus is used to build an indoor pro-biotic environment to maintain or improve the physical and mental health of people in indoor, the environmental conditions should be controlled properly, especially CO2 concentration and air temperature, so as to fully and efficiently produce the positive health benefits from P. hadiensis var. tomentosus. [ABSTRACT FROM AUTHOR]

The emission characteristics of VOCs (volatile organic compounds) from laminate flooring were investigated and their impacts on indoor environment evaluated in order to provide basic data for the study of harmful gas release from laminate flooring, and to provide reference for producers and consumers to evaluate their effects on indoor air quality. In this study, Shuang Xiang laminate flooring was selected and sampled with 1 m 3 climate chamber method. The sampled VOCs were analyzed by GC-MS (gas chromatography-mass spectrometry) and according to the forestry industry standards LY/ T 3230-2020 “Classification of volatile organic compound emissions contents from wood-made panels and their finishing products” and LY/ T 3229 - 2020 “ Specification for indoor carrying capacity of wood-based panels and finishing products based on volatile organic compounds emission”, the laminate flooring on indoor air quality was evaluated. Results showed that the TVOC release of this laminate flooring gradually decreased with time and reached the release equilibrium at day 28. The VOCs released were mainly olefins, aromatic hydrocarbons and alkanes, with small amounts of aldehydes, ketones, lipids and alcohols. In one cycle, the release level of naphthalene on the 3rd day of the laminate flooring did not meet the Class I standard, and the release levels of several major pollutants were Class I at the rest of the time. VOCs composite index of laminate flooring decreased with the increase of time after the 3rd day, and according to the composite index grading standard, the VOCs release class of laminate flooring on the 3rd day was Class Ⅱ, and the indoor air quality was qualified, and the VOCs release class of the rest of the time was Class I, and the indoor air quality was excellent. The TVOC release rate of this laminate flooring gradually decreased with time, in line with the mass transfer principle. After the VOCs were released in equilibrium, the release class is in line with Class I. The calculated composite index was in line with Class I. The indoor air quality was excellent and consumers can use it with confidence [ABSTRACT FROM AUTHOR]

In order to solve the problem of poor indoor air quality in teaching buildings of natural ventilation colleges and universities in cold areas, the temperature and humidity, CO2 concentration, wind speed and other parameters of 13 natural ventilation classrooms in a university in Xi’an were monitored. At the same time, 698 students′ subjective evaluation of indoor temperature, humidity and air quality were recorded. The results show that the average clothing thermal resistance in winter is 1.29 clo, and the indoor thermal neutral temperature is 20.7℃. Except for the humidity, the temperature and CO2 concentration in the tested classroom do not meet the requirements of national indoor air quality standards. Combined with the students′ evaluation of indoor air quality, it is concluded that the unreasonable use of doors and windows for ventilation has led to poor indoor air circulation, the overall environment comfort degree and satisfaction level the students percieved during class is low, such as by drowsiness, dry skin, decreased concentration, and emotional depression. [ABSTRACT FROM AUTHOR]