Investigation Of The Physiological Acclimation Mechanisms And The Humidity Environment Parameter Requirements In The People Entering Tibet

In the Tibetan plateau,the air is dry and thin.Long-term exposure to high aridity for travelers to Tibet can cause skin and respiratory problems as well as constitute a serious threat to their comfort and health.The majority of research on indoor thermal and humid environments in China concentrates on the Yangtze River valley,southern thermal and humid areas,and other low-altitude areas at the moment.Evaluation of humidity environments also mostly uses the humidity subjective evaluation scale based on the thermal comfort assessment scale.The human body in a dry environment is primarily non-dominant sweating,with features of multiple sites and diverse symptoms,in contrast to the dominating characteristic of the human body in a humid environment,which is primarily sweat secretion.Yet,because different body parts perceive and tolerate dry environments to varying degrees,it is not adequate to accurately capture the precise dryness experience of the human body from the standpoint of subjective sensation.Simple evaluation that relies just on the thermal sensation evaluation scale can easily result in issues like inaccurate assessments of human dryness and inconsistent comfort predictions.For the issue of humidity comfort and humidity environment creation for shortterm personnel entering Tibet,it is necessary to clarify the mechanism by which an extremely dry environment influences human physiology in this paper.It is also necessary to obtain the acclimatization characteristics of people entering Tibet in a dry environment and to propose an evaluation method for humidity comfort that is appropriate for a highland dry environment as well as appropriate humidity environment design parameters.This paper combines literature research with experimental testing,field investigation,and modeling analysis.First,subjective and objective evaluation indices of the potential impact of high-altitude dry environments on humidity sensation were chosen.Next,through experimental research,the subjective and objective dry response characteristics of people entering Tibet under different dry environments were compared,and the acclimatized dry response properties of the human body in various plateau dry environments were understood.Then,we eliminated the variables best suited for identifying the humidity comfort level of the travelers,combined the indicators of subjective and objective physiological symptoms,built the Travelers’ humidity comfort evaluation technique,and checked the proposed model’s accuracy using the information gathered from the field research.Lastly,using the research data,we determined the ideal interior temperature and humidity parameters for the plateau dry environment and compared the new model with the current model to define the model’s applicability and utility.The results showed the following:(1)The Travelers will progressively acclimate to the dry conditions of the plateau,and the time of residence on the plateau affects how the Travelers will respond to the dry conditions.People entering Tibet are initially adapted to the plateau dry environment after the seventh day.Once they are adapted to the plateau dry environment,the human physiological reaction and indoor humidity changes are enhanced,and the human body’s perception of indoor humidity is improved.As the time in Tibet was extended,the relative humidity of the skin’s surface rose by roughly 3%every day throughout the first week.(2)The lips are the body part most sensitive to variations in humidity,followed by the nasal cavity,the throat,the skin,and the eyes,while different body parts exhibit different sensitivity to the dry climate of the plateau.The level of dryness in various body parts was highest on the sixth and seventh day in Tibet,and the dryness of the lips and nasal cavity grew by around 0.5 standard degrees every day.In the second week of Tibet,ocular dryness was the most consistent,fluctuating on average by less than 0.1standard degrees and essentially remaining constant regardless of changes in interior humidity.(3)Environment temperature and humidity together had an impact on the humidity of the Travelers.The winter-comfortable indoor relative humidity was 47.6%,41.5%,and 33.7% for subjects who entered Tibet for one week,one month,and one year,respectively,while the inside temperature into the Travelers’ was 19.2°C thermoneutral.Corrected indoor relative humidity values were 42.6%,36.1%,and 32.5%,respectively.This is lower than the original statistics by 10.5%,12.0%,and 3.6%.The internal humidity of the plateau building should be kept above 42% to assure the comfort of the people entering Tibet at each stage.(4)The humidity comfort evaluation method suggested in this study for the population entering Tibet can correct for some of the measured humidity comfort levels with significant differences,reducing the phenomenon that some subjects’ low tolerance for the dry environment causes the chosen humidity comfort level to be excessively high in comparison to the predicted comfort level corresponding to their actual symptoms of dryness.Within a week of entering Tibet,the relative humidity difference before and after correction is the largest,and the error is typically above 20%.The difference between the error before and after adjustment in the case of "uncomfortable but tolerable" humidity comfort is above 50%,within a year of entering Tibet.We gained knowledge of the features of the Travelers’ dry responses in various dry environments through this study.In contrast to the way of evaluating human comfort solely from a subjective standpoint,the evaluation results are more accurate,and subjective evaluation mistakes caused by individual differences in subjects’ sensitivity to and acceptance of the dry environment are eliminated.The study’s findings can serve as a guide for producing a humid environment indoors in high-altitude buildings.