Study On Health Effects And Environmental Influencing Factors Of Perceived Dryness

Perception of“dry air”is a major and abundant indoor air quality complaint,and it is considered to have an important impact on human health and comfort.It is necessary to find out the effective measures to control the perceived dryness.This study focuses on the health effects of air dryness perception and the influencing factors of perceived dryness.This study was carried out university dormitories in Tianjin from November 2019 to January 2021.The study consisted of two phases.In the phase I,we discovered the associations of perceived dryness with sick building syndrome symptoms among 2154 students.In the phase II,a pilot test and a case-control study were carried out.The pilot test was carried out in 13 dormitory rooms and the case-control study in 515 dormitory rooms,during which the environmental parameters including indoor air temperature,humidity,CO₂ concentrations（to calculate ventilation rate）and VOCs concentrations were measured..It shows that perceived dryness was significantly associated with all symptoms of sick building syndrome（p<0.05）.Therefore,it is reasonable to speculate that perceived dryness is an indicator for health and comfort problems such as sick building syndrome.Decreases in temperature,and humidity increased perceived dryness.In the case-control test,relative humidity had a significant impact on students’perceived dryness.Multilevel logistic regression analysis showed that Decanal was significantly positively correlated with students’perceived dryness.There was a significant negative correlation between terpenes such as Carene and perceived dryness.We speculated that the secondary pollutants produced by the reaction of terpenes with ozone were the“bad actors”causing perceived dryness.After adjustment of relative humidity,the association between VOCs and perceived air dryness were still significant.Through this study,we obtained information on health effects and influencing factors for perceived air dryness.It will provide important scientific basis for improving dormitory environment and preventing health problems among students.