Spatiotemporal distributions for prevalences of indoor damp indicators in residences from 1980 to 2020 in China

Few studies assessed the long-term changes in the prevalence of indoor damp indicators in residences. In this paper, we tried to clarify nationwide spatial-temporal distributions of the prevalences of damp indicators in residences in the past four decades in China and compared the prevalences in other countries. A systematic review was conducted in three Chinese-language databases and two English-language databases from January 1980 to December 2020 according to the guidelines of PRISMA (preferred reporting items for systematic review and meta-analysis). After reviewing 5580 documents, 86 articles that provided specific data were retained for the review of prevalences of damp indicators in residences. Windowpane condensation was the most common damp indicator in residences (averaged: 34.1%, 95% CI: 28.1–40.1), followed by damp clothing and/or bedding (26.5%, 95% CI: 22.0–31.0), mouldy odour (13.3%, 95% CI: 10.4–16.2), water damage (12.5%, 95% CI: 8.6–16.5), visible mould spots (12.2%, 95% CI: 8.7–15.7) and visible damp stains (11.8%, 7.1%–16.5%) in dwellings in China. In the past four decades, increasing trends of window pane condensation prevalences and mouldy odour were noted and trend was then declined after 2010, whereas prevalences of water damage and visible damp stains were generally shown to produce decreasing trends in the surveys. Our findings provide comprehensive data for the evaluation of indoor damp indicators in residences in China.