RESEARCH ARTICLE


Approaches to Calculation of Average Exposure in Analysis of Epidemiologic Cohorts Using Large Arylonitrile Cohort As An Example



Leonid Kopylev*
National Center for Environmental Assessment, Office of Research and Development, United States Environmental Protection Agency, Washington, DC, USA

Article Information


Identifiers and Pagination:

Year: 2014
Volume: 7
First Page: 1
Last Page: 5
Publisher Id: TOEPIJ-7-1
DOI: 10.2174/1874297120140515001

Article History:

Received Date: 23/01/2014
Revision Received Date: 07/05/2014
Acceptance Date: 09/05/2014
Electronic publication date: 30/5/2014
Collection year: 2014

© 2014Kopylev et al..

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Environmental Protection Agency, Washington, DC, USA; Tel: 703 347 8599;Fax: +1 703 347 8692; E-mail: kopylev.leonid@epa.gov


Abstract

Objectives:

To explore two different approaches to calculate average exposure in occupational cohorts using a large occupational cohort as an example. The data for occupational cohort exposed to acrylonitrile was collected and analyzed previously by NCI; outcome was lung cancer.

Methods:

Both approaches use cumulative exposure as the numerator. As the denominator, one uses the duration of exposure, while the other uses the length of employment. The former approach is used when detailed exposure history is available, and the latter is usedwhen exposure history is less detailed. The differences are investigated for a large occupational cohort.

Results:

Both approaches use cumulative exposure as the numerator. As the denominator, one uses the duration of exposure, while the other uses the length of employment. The former approach is used when detailed exposure history is available, and the latter is usedwhen exposure history is less detailed. The differences are investigated for a large occupational cohort.

Conclusions:

Both approaches should be considered when calculating an average exposure metric.

Keywords: Cumulative exposure, average intensity, acrylonitrile, JEM.