呼吸系统疾病的周期性变化在冬季最高，夏季最低，其原因一直是许多论文和调查的主题。最常见的假设是，这种循环是由室内相对湿度的变化引起的，室内相对湿度冬季最低，夏季最高。文献中报告的八项研究比较了两栋楼或两个房间的居住者缺勤或呼吸系统疾病的数量和持续时间，其中一个房间的相对湿度高于另一个房间。在八项研究中，有六项研究表明，在潮湿的空间中，缺勤或呼吸系统疾病的发生率显著降低。 本文报告了在医院进行的最新研究，并讨论了评估调查结果的困难。该研究得出的结论是，冬季室内相对湿度的增加很可能会降低呼吸系统疾病的发病率，鉴于旷工的成本，有必要进行进一步的实验。引文:研讨会，ASHRAE交易，1985年，第91卷，pt。1B芝加哥

The cause of the cyclical variation of respiratory illnesses that are highest in winter and lowest in summer has been the subject of many papers and investigations. The most common hypothesis is that the cycle is caused by the variation of indoor relative humidity, which is lowest in winter and highest in summer. Eight studies reported in the literature compare absence from work or number and duration of respiratory illnesses of the occupants of two building or two rooms, one of which is maintained at a higher relative humidity than the other. In six of the eight studies, the absence from work or the occurrence of respiratory illnesses are significantly lower in the humidified space. This paper reports the latest study that was conducted in hospitals and discusses the difficulties in assessing the results of the investigations. It concludes there is a high probability that increased indoor relative humidity in winter decreases the number of respiratory illnesses and that further experiments are warranted in view of the cost of absenteeism from work.