Indoor fungal infestations and mycotoxicity: guidance for public health professionals and industrial hygienists

Introduction and scope. “Mold spores are omnipresent, and a constantly elevated humidity in given building containing organic components will inevitably lead to [fungal] growth and subsequent damage to the materials” (Gravensen, 1999). In recent years indoor fungal growth and airborne particles have gained the reputation of a serious health threat. The extent to which this perception is justified is controversial. We know that mold dust and spores can be allergenic, and that excessive exposure to fungal materials can cause infectious respiratory ailments. We also know that some mold species may produce toxic secondary metabolites. Less clear is the extent to which the presence of fungal material represents an imminent threat to human heath. Health experts agree that visible mold growth should be discouraged in the indoor environment, and that management of the indoor environment should take the form of controlling indoor humidity, disinfecting surfaces with visible mold growth, and discarding moldy articles. These are recommendations for general indoor sanitation and do not necessarily recognize indoor mold as an acute health threat. However, in recent years it has become common to confront visible indoor mold with professional assessments and drastic, costly remedies. Such measures may not be beneficial, and may cause unneeded economic stress and disruption. The purpose of this review is to provide guidance on indoor mold and mycotoxicity to the public health community. This review, while focusing on mycotoxicity, will argue that the health effects claimed to follow from inhalational exposure to fungal particles in residential, school, and office settings are poorly documented and probably multifactorial. A better understanding of the routes and effects of exposure to mold is needed in order to make proper public health decisions.