Response letter to the Editor RE: Formaldehyde and leukemia: missing evidence!

Abstract

We appreciate Dr. Morfeld's [1] interest in our recent review of the epidemiologic evidence for associations of formaldehyde with the lymphohematopoietic malignancies [2]. He notes the omission of a letter exchange [3] concerning evidence for hematotoxicity and chromosome damage among Chinese workers exposed to formaldehyde [4]. Although this exchange raised some provocative questions, it does not alter our conclusion that the proposed leukemogenesis mechanisms for formaldehyde remain unsubstantiated. As Morfeld mentions, we did neglect to cite the meta-analysis by Schwilk et al.[5], although we have critically reviewed all of the primary literature that formed the basis of this meta-analysis. We maintain that, owing to the heterogeneity of the literature in terms of health outcome definition and exposure assessment, metaanalyses of formaldehyde and risks for leukemia and lymphoma are not readily interpretable. This was a main motivation for our systematic, critical review of the evidence presented in the published epidemiologic literature. Conflict of interestThe authors declare that they have no conflicts of interest.