Indoor mould exposure: Characteristics, influences and corresponding associations with built environment—A review

Abstract

While household mould growth has been increasingly highlighted in response to its adverse health outcomes and building management burden, studies are reviewed respectively from perspective of epidemiological survey, or building technology. This paper thus presents a literature review to address the building environment and mould exposure in homes, including the mould growth and exposure characteristics, interaction with building features, design requirements from current standards. The review indicates that mould growth favors damp indoor environments in homes and is positively facilitated by warm temperature and high humidity, releasing spores such as Cladosporium, Aspergillus, and Penicillium into air and resulting in sensitization and activation of allergic responses in airways like asthma. The building energy efficient designs, such as increased insulation and airtightness improve the thermal environment but possibly accumulate indoor moisture and increase mould growth risks, due to lack of sufficient ventilation. While current indoor humidity and/or mould related standards do not fully emphasize refined requirements, as a result of the diversity of mould species, temporal and spatial variations; due to variation in individual susceptibility, the critical thresholds for mould exposure safety have not been linked to health risk and clearly established. Therefore, this review suggests a multidisciplinary cooperation of epidemiology, building technology, as well as biological and molecular research in future, to facilitate understandings of the causal mechanism, quantitative assessment, and acceptable thresholds for mould exposure and management in buildings.