Funding for this research was provided by:
National Cancer Institute (Z01-CP010119)
National Institute of Environmental Health Sciences (Z01-ES049030, P30 ES005022)
Received: 20 March 2017
Accepted: 14 August 2017
First Online: 6 September 2017
Ethics approval and consent to participate
: Study procedures and documents were approved in 1993 by the National Cancer Institute Special Studies Institutional Review Board, Westat Institutional Review Board, and the University of Iowa Institutional Review Board-01.
: Not applicable.
: The authors declare that they have no competing interests.
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