title: Geographic distribution of Environmental Relative Moldiness Index molds in USA homes.
abstract: OBJECTIVE
  The objective of this study was to quantify and describe the distribution of the 36 molds that make up the Environmental Relative Moldiness Index (ERMI).
  
  
  METHODS
  As part of the 2006 American Healthy Homes Survey, settled dust samples were analyzed by mold-specific quantitative PCR (MSQPCR) for the 36 ERMI molds. Each species' geographical distribution pattern was examined individually, followed by partitioning analysis in order to identify spatially meaningful patterns. For mapping, the 36 mold populations were divided into disjoint clusters on the basis of their standardized concentrations, and First Principal Component (FPC) scores were computed.
  
  
  CONCLUSIONS
  The partitioning analyses failed to uncover a valid partitioning that yielded compact, well-separated partitions with systematic spatial distributions, either on global or local criteria. Disjoint variable clustering resulted in seven mold clusters. The 36 molds and ERMI values themselves were found to be heterogeneously distributed across the United States of America (USA).
authors.affiliation: National Exposure Research Laboratory, United States Environmental Protection Agency, Cincinnati, OH 45268, USA. vesper.stephen@epa.gov
authors.forename: Stephen
authors.initials: S
authors.lastname: Vesper
authors.forename: Jennie
authors.initials: J
authors.lastname: Wakefield
authors.forename: Peter
authors.initials: P
authors.lastname: Ashley
authors.forename: David
authors.initials: D
authors.lastname: Cox
authors.forename: Gary
authors.initials: G
authors.lastname: Dewalt
authors.forename: Warren
authors.initials: W
authors.lastname: Friedman
mesh_terms: D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D005658:Fungi / Q000145:classification* / Q000302:isolation & purification*; D005843:Geography; D006306:Health Surveys / Q000379:methods; D006798:Housing; D016133:Polymerase Chain Reaction / Q000379:methods; D025341:Principal Component Analysis; D012044:Regression Analysis; D014481:United States
chemical_list: D004391:Dust