This year’s Society for Risk Analysis (SRA) Annual Meeting (Dec. 8-11 in Baltimore) includes a symposium on integrating the science on formaldehyde, in hopes of better understanding the potential for formaldehyde carcinogenicity, as well as providing high quality information to help inform public health (including regulatory) decisions for compounds like formaldehyde that present complex challenges.
An internationally recognized expert in toxicology and risk analysis, Joseph V. Rodricks, PhD, DABT, and founding Principal of ENVIRON, answers the following questions about the upcoming SRA symposium on formaldehyde.
Q. What do you plan to cover in this symposium?
The SRA Symposium will examine of all of the significant scientific information bearing on the question of formaldehyde’s carcinogenicity. Included are occupational epidemiology studies, studies of formaldehyde’s pharmacokinetic behavior that bear on its potential to reach critical precursor cells, and mode-of-action studies. New information on biological processes involved in leukemia production, and their relationship to what is known about formaldehyde’s mode-of-action, will be presented. The relative roles of endogenous and exogenous production of formaldehyde also will be discussed.
Q. Why do you believe that it is important for SRA’s annual meeting to cover formaldehyde as a topic this year?
Human exposures to formaldehyde are ubiquitous. The compound is used in and emitted from a large array of products and is emitted during the combustion of fossil fuels and other organic matter, including tobacco. It is naturally present in foods, and occurs in the human body as a normal product of metabolism. This phenomenon is not unique to formaldehyde—–other industrial compounds have similar endogenous production— and what is being learned about formaldehyde likely will have broad application in the evaluation of other compounds.
The health effects of formaldehyde have been the subject of a vast amount of epidemiological and experimental research. Of greatest importance is the question of the compound’s carcinogenicity, particularly its possible role in the causation of leukemia and other lymphohematopoetic cancers. Whether such a causal relationship exists has great importance for regulatory and other public health communities, and for the medical community, given the widespread human exposure to this substance, as well as its endogenous presence. In addition, how risk assessments are conducted for this compound are of significance for the risk assessment community. This SRA symposium is timely, important at both scientific and policy levels, and deals with scientific challenges of the highest order.
Q. What do the epidemiological data tell us about formaldehyde and lymphohematopoetic cancer?
The epidemiological evidence is inconsistent and varies considerably by specific types of leukemia or lymphoma. It is unlikely that all of these different cancers share the same causes or risk factors, so it is important to look at the evidence for each specific type of cancer. Myeloid leukemias (especially acute myeloid leukemias, or AMLs) have been of particular interest. Furthermore, few studies have reasonably quantified levels of formaldehyde exposure for each member of a study. This highlights the need for close examination of all of the epidemiological data from stronger studies, and consideration of the toxicological and mode of action data as well.
Q. Why is it important to integrate the epidemiological and mode-of-action data to address whether there is in fact an association with formaldehyde and lymphohematopoetic cancer?
The SRA Symposium will conclude with a thorough, state-of -the art, WOE evaluation of the entire data base for formaldehyde. The integration of the available data for formaldehyde is relevant to the current and highly public discussion of the proper role for and conduct of WOE evaluations. And as mentioned, the difficult scientific challenges related to endogenous production of formaldehyde in the human body are sure to be important for assessing other industrial chemicals.
Q. How is this symposium relevant to the ongoing EPA IRIS Assessment and the National Academy of Sciences review of the formaldehyde listing in the 12th Report on Carcinogens?
The Symposium is highly relevant to ongoing and extensive activities on formaldehyde in federal and state governments, and to the National Academy of Sciences review of the listing of formaldehyde as a cause of human cancer in the National Toxicology Program’s 12th Report on Carcinogens.
Q. Will the proceedings of this symposium be made available to the public?
The slide presentations will be made available to the public upon request. The majority of the material presented either is currently available in the published literature or will be part of publications that are in preparation.