title: Formation and emission of chloroanisoles as indoor pollutants.
abstract: OBJECTIVE
  Complaints by residents of frame-houses about musty odour in the houses has become an increasing problem within the last years. An additional problem is that the odour is transferred to clothes and skin. The persons themselves do not recognize the smell after a while because of adaptation. Serious social problems are the result. For a long time, the smell was explained to be from mould due to construction-based humidity problems. However, in an increasing number of houses, no indications were found for elevated levels of mould growth.
  
  
  METHODS
  Air and material samples were taken from 5 houses, which show typical musty odours, and analysed with respect to chlorophenols and chloroanisoles. Additionally, some samples were analysed for lindane and its metabolites, because lindane was commonly used together with pentachlorophenol (PCP) for wood protection.
  
  
  CONCLUSIONS
  Meticulous analysis resulted in the identification of chloroanisoles, mainly 2,3,4,6-tetrachloroanisole. These substances are known from corky wines and from contamination of food from pentachlorophenol (PCP) treated pallets and result from microbiological metabolic processes. Pentachlorophenol was commonly used to protect wood from fungi in Germany mainly in the later 60s and 70s. Details of these processes, as well as effective methods to identify chloroanisoles in the problem houses, are described.
  
  
  CONCLUSIONS
  Chloroanisoles formed by metabolism of PCP have been well known to contaminate food or wine. Here, they were identified and are probably responsible for the musty odours in the frame houses. Since it is quite clear that these substances were not components of building materials used in the houses, an explanation for chloroanisole formation is proposed. Localized dampness probably favours microbial growth associated with metabolic conversion of chlorophenols to the corresponding chloroanisoles, primarily 2,3,4,6-tetrachloroanisol, which spread throughout the buildings, resulting in the observed odours.
  
  
  CONCLUSIONS
  The group of chloroanisoles has been recognized as important indoor pollutants as they possess musty odours at extremely low concentrations, e.g. for 2,4,6-trichloroanisole in a range of 5-10 ppt in air (Staples 2000). On the basis of currently available toxicological data, exposure of the occupants to the concentrations of chloroanisoles measured is not associated with a health risk. No correlation could be observed between concentrations of chloroanisoles and PCP in house dust and indoor air. However, chloroanisoles are good indicators for possible PCP-treatment of wood in frame houses and their detection should initiate investigations on PCP contamination. Research is continuing to identify the microorganisms involved and to devise a remediation procedure for affected houses.
authors.affiliation: Fraunhofer-Institut für Holzforschung, Wilhelm-Klauditz-Institut, Bienroder Weg 54E, D-38 108 Braunschweig, Germany. jan.gunschera@wki.fhg.de
authors.forename: Jan
authors.initials: J
authors.lastname: Gunschera
authors.forename: Frank
authors.initials: F
authors.lastname: Fuhrmann
authors.forename: Tunga
authors.initials: T
authors.lastname: Salthammer
authors.forename: Andrea
authors.initials: A
authors.lastname: Schulze
authors.forename: Erik
authors.initials: E
authors.lastname: Uhde
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D000840:Anisoles / Q000032:analysis* / Q000378:metabolism; D002733:Chlorophenols / Q000032:analysis* / Q000378:metabolism; D004785:Environmental Pollutants / Q000032:analysis* / Q000378:metabolism; D005506:Food Contamination; D005858:Germany; D001556:Hexachlorocyclohexane / Q000032:analysis; D006798:Housing; D006801:Humans; D009812:Odorants / Q000032:analysis; D010416:Pentachlorophenol / Q000032:analysis / Q000378:metabolism; D014934:Wood
chemical_list: D000840:Anisoles; D002733:Chlorophenols; D004785:Environmental Pollutants; D001556:Hexachlorocyclohexane; C009408:tetrachlorophenol; D010416:Pentachlorophenol