Peak Exposures in Epidemiologic Studies and Cancer Risks: Considerations for Regulatory Risk Assessment

Harvey Checkoway, Peter Sj Lees, Linda D. Dell, P. Robinan Gentry, Kenneth A. Mundt

Research output: Contribution to journalArticle

Abstract

We review approaches for characterizing “peak” exposures in epidemiologic studies and methods for incorporating peak exposure metrics in dose–response assessments that contribute to risk assessment. The focus was on potential etiologic relations between environmental chemical exposures and cancer risks. We searched the epidemiologic literature on environmental chemicals classified as carcinogens in which cancer risks were described in relation to “peak” exposures. These articles were evaluated to identify some of the challenges associated with defining and describing cancer risks in relation to peak exposures. We found that definitions of peak exposure varied considerably across studies. Of nine chemical agents included in our review of peak exposure, six had epidemiologic data used by the U.S. Environmental Protection Agency (US EPA) in dose–response assessments to derive inhalation unit risk values. These were benzene, formaldehyde, styrene, trichloroethylene, acrylonitrile, and ethylene oxide. All derived unit risks relied on cumulative exposure for dose–response estimation and none, to our knowledge, considered peak exposure metrics. This is not surprising, given the historical linear no-threshold default model (generally based on cumulative exposure) used in regulatory risk assessments. With newly proposed US EPA rule language, fuller consideration of alternative exposure and dose–response metrics will be supported. “Peak” exposure has not been consistently defined and rarely has been evaluated in epidemiologic studies of cancer risks. We recommend developing uniform definitions of “peak” exposure to facilitate fuller evaluation of dose response for environmental chemicals and cancer risks, especially where mechanistic understanding indicates that the dose response is unlikely linear and that short-term high-intensity exposures increase risk.

Original languageEnglish (US)
JournalRisk Analysis
DOIs
StatePublished - Jan 1 2019

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Risk assessment
Epidemiologic Studies
Neoplasms
United States Environmental Protection Agency
Environmental Protection Agency
Acrylonitrile
Epidemiologic Methods
Ethylene Oxide
Carcinogens
Trichloroethylene
Styrene
Environmental Exposure
Benzene
Formaldehyde
Inhalation
Ethylene
Language
Oxides

Keywords

  • Cancer epidemiology
  • peak exposure
  • risk assessment

ASJC Scopus subject areas

  • Safety, Risk, Reliability and Quality
  • Physiology (medical)

Cite this

Peak Exposures in Epidemiologic Studies and Cancer Risks : Considerations for Regulatory Risk Assessment. / Checkoway, Harvey; Lees, Peter Sj; Dell, Linda D.; Gentry, P. Robinan; Mundt, Kenneth A.

In: Risk Analysis, 01.01.2019.

Research output: Contribution to journalArticle

Checkoway, Harvey ; Lees, Peter Sj ; Dell, Linda D. ; Gentry, P. Robinan ; Mundt, Kenneth A. / Peak Exposures in Epidemiologic Studies and Cancer Risks : Considerations for Regulatory Risk Assessment. In: Risk Analysis. 2019.
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