title: Formaldehyde exposure and leukemia: critical review and reevaluation of the results from a study that is the focus for evidence of biological plausibility.
abstract: A recent study (Zhang et al., 2010) has provided results attributed to aneuploidy in circulating stem cells that has been characterized as providing potential support for proposed mechanisms for formaldehyde to impact bone marrow. A critical review of the study, as well as a reanalysis of the underlying data, was performed and the results of this reanalysis suggested factors other than formaldehyde exposure may have contributed to the effects reported. In addition, although the authors stated in their paper that "all scorable metaphase spreads on each slide were analyzed, and a minimum of 150 cells per subject was scored," this protocol was not followed. In fact, the protocol to evaluate the presence of monosomy 7 or trisomy 8 was followed for three or less samples in exposed workers and six or less samples in non-exposed workers. In addition, the assays used (CFU-GM) do not actually measure the proposed events in primitive cells involved in the development of acute myeloid leukemia. Evaluation of these data indicates that the aneuploidy measured could not have arisen in vivo, but rather arose during in vitro culture. The results of our critical review and reanalysis of the data, in combination with recent toxicological and mechanistic studies, do not support a mechanism for a causal association between formaldehyde exposure and myeloid or lymphoid malignancies.
authors.affiliation: ENVIRON International Corporation, Monroe, LA 71201, USA. rgentry@environcorp.com
authors.forename: P Robinan
authors.initials: PR
authors.lastname: Gentry
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Rodricks
authors.forename: Duncan
authors.initials: D
authors.lastname: Turnbull
authors.forename: Annette
authors.initials: A
authors.lastname: Bachand
authors.forename: Cynthia
authors.initials: C
authors.lastname: Van Landingham
authors.forename: Annette M
authors.initials: AM
authors.lastname: Shipp
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Albertini
authors.forename: Richard
authors.initials: R
authors.lastname: Irons
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000633:toxicity; D002872:Chromosome Deletion; D002897:Chromosomes, Human, Pair 7 / Q000187:drug effects / Q000235:genetics; D002898:Chromosomes, Human, Pair 8 / Q000187:drug effects / Q000235:genetics; D004249:DNA Damage / Q000187:drug effects; D004195:Disease Models, Animal; D005557:Formaldehyde / Q000633:toxicity*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000209:etiology / Q000235:genetics / Q000473:pathology*; D016273:Occupational Exposure / Q000032:analysis*; D013234:Stem Cells / Q000187:drug effects / Q000473:pathology; D014314:Trisomy / Q000235:genetics
chemical_list: D002273:Carcinogens; D005557:Formaldehyde