title: Comment on "designing EMF experiments: what is required to characterize 'exposure'?".
abstract: Dr. Peter Valberg has written an excellent and clear paper describing our current understanding of the many facets of characterizing exposure to extremely-low-frequency (ELF) electric and magnetic fields. Dr. Valberg has directed his paper to the characterization of exposures used in laboratory experimentation. In this context, it seems to me that Valberg's program of exposure characterization can be accomplished with currently available instrumentation and with relatively modest effort. Thus, I have no fundamental problems with his recommendations and, really, have only a few minor comments to make. However, if one argues that Valberg's recommendations should be extended to the characterization of exposure in epidemiological research, I have serious reservations, which I will mention briefly at the end of this commentary.
authors.affiliation: EM Factors, Richland, Washington, USA.
authors.forename: W T
authors.initials: WT
authors.lastname: Kaune
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004812:Epidemiologic Methods; D006801:Humans; D012107:Research Design