Influence of Climate Variation on Indoor Air Quality; a 15-year Profile Analysis of Indoor Fungal Pollutants

摘要

Buildings are major and only shelters for human to refrain from direct impacts of climate change and rising frequency of disasters. The importance of indoor environment quality is therefore more critical while the time people spent indoors is ever more increasing. Furthermore, higher ambient temperature and more extreme weather events are suggested to result in worsen indoor air quality, as a consequence from in-outdoor interaction. Yet, the physical and chemical impact of climate change on indoor environment remains relatively unclear. The aim of this study is to evaluate the effects of potential climatic or weather variations on indoor air pollutants (IAP), using a 15-year monitoring data collected from 802 different buildings span throughout the island of Taiwan. The profile of total culturable fungal concentration, reported to be attributable to various adverse health effects, would be taken as an example for preliminary analysis. Since 1998, our team has continuously collected IAP data from 322 home, 162 school, 106 offices and 212 public places of diverse functions, following the standard procedure of indoor investigation. A total of 1757 indoor and 1749 outdoor total culturable fungal levels are included in the analysis, with averages (sd) of 4543.1 (9518.6) CFU/m3 and 5502.4 (11013.3) CFU/m3, respectively. Highest average levels of fungi and its in-outdoor (I/O) ratio are found in the building type of school, or during the winter season (December to February). Higher temperature of 8-hour daytime average, no matter indoors (crude OR=1.17, 95%CI 1.13-1.21), outdoors (cOR=1.08, 95%CI 1.05-1.10) or atmospheric (cOR=1.06, 95%CI 1.04-1.09), is one of the major determinant for the increasing fungal I/O ratio. Moreover, fungal I/O ratio also increased with the year of investigation (adjusted OR=1.11, 95%CI 1.07-1.15) after adjusting for ambient temperature, geographical location, sampling season and type of building. This study is the first to evidence the impact of climate variation on IAPs by using a 15-years dataset.