The allergenic constituents of non-industrial indoor environments are predominantly found
in the biologic fraction. Several reports have related biological particles such as mites and
their excreta, dander from pets and other furred animals, fungi and bacteria to allergic
manifestations including respiratory hypersensitivity among the occupants of buildings. Also,
bacterial cell-wall components and the spores of toxin-producing moulds may contribute to
the induction of hypersensitivity, but the relevance for human health is not yet determined …