UC Irvine UC Irvine Electronic Theses and Dissertations Title Cancer Risks in Shipyard Workers Exposed to Asbestos and Welding Fumes Permalink https://escholarship.org/uc/item/2bc115d9 Author Cabasag, Citadel Jungco Publication Date 2016 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, IRVINE Cancer Risks in Shipyard Workers Exposed to Asbestos and Welding Fumes DISSERTATION submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY in Epidemiology by Citadel Jungco Cabasag Dissertation Committee: Professor Hoda-Anton Culver, Chair Associate Adjunct Professor Argyrios Ziogas Professor Ralph Delfino 2016 Chapter 3 © 2016 Wolters Kluwer Health, Inc. All other materials © 2016 Citadel Jungco Cabasag DEDICATION To All the women of color in science who came before me and paved the path for women like myself and the next generation of women. ii TABLE OF CONTENTS Page LIST OF FIGURES v LIST OF TABLES vi ACKNOWLEDGMENTS viii CURRICULUM VITAE ix ABSTRACT OF THE DISSERTATION xii CHAPTER 1: Introduction 1 CHAPTER 2: Methods 12 CHAPTER 3: A validation method to determine missing years of birth in a cohort study of shipyard workers using Social Security Number 28 CHAPTER 4: Causes of deaths, and incidence of cancers in the Long Beach Naval shipyard study cohort 41 CHAPTER 5: The risk of colorectal cancer between Long Beach Naval shipyard workers exposed to low, intermediate, and high asbestos exposure levels 73 CHAPTER 6: The risk of lung cancer between Long Beach Naval shipyard workers exposed to welding fumes and unexposed workers 87 CHAPTER 7: Summary and Conclusions 109 REFERENCES 115 APPENDIX A 135 APPENDIX B: Distribution of workers by asbestos exposure levels based on their shop numbers and job titles 143 APPENDIX C: Examples of the record of addresses obtained from the AlumniFinder 144 APPENDIX D: Distribution of sexual orientation by main occupational group in Long Beach Naval shipyard study cohort 145 iii APPENDIX E: Deaths classified by cause-of-death categories in the Long Beach Naval shipyard 146 APPENDIX F: Specific cause-of-deaths for diseases of the circulatory, respiratory, and digestive systems as well as accidents, suicides, and homicides categories 147 APPENDIX G: Deaths classified by cause-of-deaths categories in the Long Beach Naval shipyard study cohort by asbestos exposure groups 150 APPENDIX H: Cancer-specific deaths in the LBNS study cohort 152 APPENDIX I: Cancer-specific deaths in the LBNS study cohort by asbestos exposure groups 153 APPENDIX J: Primary cancers in the LBNS study cohort including Office workers and Administrative personnel 155 APPENDIX K: Site-specific primary cancers in the LBNS study cohort 156 APPENDIX L: Primary cancers in the main occupational group, Office workers and Administrative personnel 157 APPENDIX M: Primary cancers in the LBNS study cohort by asbestos exposure groups 158 APPENDIX N: Cancer-specific age-standardized incidence ratio in the male Long Beach Naval shipyard workers compared to the general population of California by main occupational group 161 APPENDIX O: Modified grouping of the main occupations in the Long Beach Naval shipyard study cohort 166 APPENDIX P: Graphs of log of the negative log of the estimated survivor functions to check proportional hazard assumptions for the outcomes colorectal cancer and lung cancer 167 APPENDIX Q: Lung cancer stratified by asbestos exposure groups 170 APPENDIX R: Kaplan-Meier curve for lung cancer in the Long Beach Naval shipyard cohort by asbestos exposure and duration of employment 171 iv LIST OF FIGURES Page Figure 2.1 Flow chart of the study population 12 Figure 2.2 Method in defining occupational categories in the Long Beach Naval shipyard study cohort 17 Figure 2.2 Scatter plots of employee ID numbers and year-of-hire of Long Beach Naval shipyard workers between 1978 and 1985 24 Figure 1 Outline of the Long Beach Naval shipyard cohort (1978-1985) validation study of Block’s method to predict years of birth using Social Security Numbers 37 Figure 2 Relationships between predicted and observed years of birth in LBNS-VC workers 38 Figure 5.1 Distribution of age-at-diagnosis for colorectal cancer in the Long Beach Naval shipyard 77 Figure 5.2 Kaplan-Meier curve for colorectal cancer in the Long Beach Naval shipyard study cohort by asbestos exposure groups 79 Figure 5.3 Kaplan-Meier curve for colorectal cancer in the Long Beach Naval shipyard study cohort by asbestos exposure groups adjusted for duration of employment in the shipyard 80 Figure 6.1 Kaplan-Meier curve for lung cancer in the Long Beach Naval shipyard study cohort by welding fumes exposure clusters 105 Figure 6.2 Kaplan-Meier curve for colorectal cancer in the Long Beach Naval shipyard study cohort by welding fumes exposure clusters adjusted for duration of employment in the shipyard 106 v LIST OF TABLES Page Table 2.1 The distribution of Long Beach Naval shipyard study cohort workers with known job titles occupational categories and shop numbers 18 Table 2.2 List of occupational agents in the 1983 & 1985 Long Beach Naval shipyard questionnaire survey 19 Table 2.3 Occupational categories in each asbestos exposure level in the Long Beach Naval shipyard study cohort 21 Table 1 Distribution of the Social Security Number Median Age of Issue 32 Table 2 Comparison of Modifications of Block’s Prediction Method Using the Long Beach Naval shipyard cohort (1978-1985) 33 Table 3 U. Territories- and states-issued Social Security Number in the Long Beach Naval shipyard cohorts, 1978-1985 35 Table 4.1 Overall age-specific standardized mortality ratio in the Long Beach Naval shipyard study cohort 45 Table 4.2 Age-specific standardized mortality ratio in the Long Beach Naval shipyard study cohort by asbestos exposure groups 47 Table 4.3 Cancer-specific age-specific standardized mortality ratio in the Long Beach Naval shipyard study cohort 48 Table 4.4 Cancer-specific age-adjusted standardized mortality ratio in the Long Beach Naval shipyard study cohort by asbestos exposure groups 50 Table 4.5 Primary cancers in the Long Beach Naval shipyard study cohort excluding Office workers and Administrative personnel 53 Table 4.6 Cancer-specific age-specific standardized incidence ratio in male Long Beach Naval shipyard workers compared to the general population of California 54 Table 4.7 Primary cancers in the Long Beach Naval shipyard cohort by asbestos exposure 56 Table 4.8 Primary cancers in the Long Beach Naval shipyard cohort by vi asbestos exposure separated by the duration of employment in Long Beach Naval shipyard 62 Table 5.1 Colorectal cancer stratified by asbestos exposure groups 78 Table 5.2 Cox proportional hazards analysis for incidence of colorectal cancer stratified by the duration of employment in the Long Beach Naval shipyard 78 Table 5.3 Distribution of stage-at-diagnosis for colorectal cancer in the Long Beach Naval shipyard 81 Table 5.4 Distribution of histological types for colorectal tumors in the Long Beach n=Naval shipyard 81 Table 6.1 List of occupational categories in the Long Beach Naval shipyard clustered according to exposure to welding fumes and asbestos 91 Table 6.2 Distribution of lung cancer cases in the Long Beach Naval shipyard by welding fumes clusters and duration of employment 93 Table 6.3 Primary cancers in the Long Beach Naval shipyard cohort by welding fumes clusters 94 Table 6.4 Primary cancers in the Long Beach Naval shipyard cohort by welding fumes clusters and duration of employment 99 vii ACKNOWLEDGMENTS I would like to express the deepest appreciation to my committee chair, Dr.
Hoda Anton-Culver. Without here expert guidance and support, this dissertation would not have been possible. I would also like to thank my committee members, Dr. Argyrios Ziogas for being patient and for all the help and advice in statistics.
I would also like to express my gratitude to Dr. Ralph Delfino giving me his time and expert advice in the topic of my research. I would also like to express my gratitude to my undergraduate interns helped me with data entries. I am also grateful for my friends and colleagues for being a constant source of motivation.
I am thankful to Teofilia Acheampong, for her friendship, the encouragements, and for always have the time to listen to my ideas and providing advice. I would also like to thank my family for the support. I am thoroughly grateful for my partner, Omar Sanchez, for the motivations, the emotional support, patience and the sacrifices throughout my PhD. I thank Wolters Kluwer Health Lippincott Williams & Wilkins for the permission to include Chapter Three of my dissertation, which was originally published in the Journal of Occupational and Environmental Medicine: 16 August 2016 – Volume 58 – Issue 6 – p 631-635.
The co- authors: Hoda Anton-Culver, PhD and Argyrios Ziogas, PhD in this publication directed and supervised research which forms the basis for the dissertation. The co-author, Merna Shehata, has also contributed to this publication. Financial support was provided by the University of California, Irvine, NIOSH Pilot Research Training Grants, and NIH F31 Individual Pre-doctoral Fellowship (1F31CA200344-01). viii CURRICULUM VITAE Citadel Jungco Cabasag ______________________________________________________________________________ EDUCATION B.
in Genetics and Cell Biology, 2005 Minor in Microbiology and Molecular Genetics, University of California, Irvine M. in Natural Science – Interdisciplinary, 2011 University at Buffalo, State University of New York Ph. in Epidemiology, 2016 University of California, Irvine RESEARCH EXPERIENCE University of California, Irvine, Department of Epidemiology, Irvine, CA 2011-2016 Graduate Student Researcher Advisor: Hoda Anton-Culver, Ph. Examined the association between colorectal cancer risk and asbestos exposure, as well as, the association between lung cancer risk and welding fumes exposure using 13,924 Long Beach Naval shipyard employed between 1978 and 1985 Occupational Health Internship Program, Los Angeles, CA 2015 Summer Research Intern Supervisor: Kevin Riley, Ph.
Collected surveys and examined the health effects as a result to interrupted sleep among Filipino domestic caregiver in southern California University at Buffalo, State University of New York, Buffalo, NY 2009-2011 Graduate Student Researcher Advisor: Christine Ambrosone, Ph. Evaluated the relationship between breast cancer risks and single nucleotide polymorphisms in cytokines and chemokines comparing African American women and European American women PUBLICATIONS Referred Journal Articles 1. A Validation Method to Determine ix Missing Years of Birth in a Cohort Study of Shipyard Workers Using Social Security Number. J Occup Environ Med 2016; 58(6):631-635.
Cytokine and Cytokine Receptor Genes of the Adaptive Immune Response Are Differentially Associated with Breast Cancer Risk in American Women of African and European Ancestry. Innate Immunity Pathways and Breast Cancer Risk in African American and European-American Women in the Women's Circle of Health Study (WCHS). Referred Conference Proceedings Cabasag C. Labor and Workplace Conditions of Domestic Live-in Caregivers in Southern California.
Presented at the 2015 American Public Health Association Conference, November 3, 2015, Chicago, Illinois. Study of workers’ health in shipyard cohort: An approach in assessment of health outcome. Presented at the 1st International Symposium to Advance Total Worker Health, October 6, 2014, Bethesda, Maryland. Evaluating the association between occupational agents and cancer risks in Long Beach Naval Shipyard cohort.
Presented at the 2013 Southern California Education and Research Center Fall Interdisciplinary Workshop, September 2013, Los Angeles, California. Cancer risk in the Long Beach Naval Shipyard Workers 1942-1997. Presented at the 2012 University of California, Irvine Foundation Dinner, November 2012, Irvine, California. Evaluating morphological defects and oxidative stress in an experimental model of fetal alcohol syndrome.
Presented at the 2008 Annual Biomedical Research Conference for Minority Students, November 5, 2008, Orlando, Florida. AWARDS University of California, Irvine President’s Dissertation Year Award 2015 School of Medicine Travel Grant, 2014 Associated Graduate Student Travel Grant 2014 x Department of Epidemiology First Year Fellowship 2011 National Institute of Health, Bethesda, Maryland Ruth L. Kirschstein Research Service Award (Award # 1F31CA200344-01) 2015 American Public Health Association James P. Keogh Scholarship 2015 Asbestos Disease Awareness Organization International Asbestos Awareness Conference Student Scholarship 2015 Southern California Education and Research Center National Institute Occupational Safety Health Pilot Research Training Grant 2012 Annual Biomedical Research Conference for Minority Students Presentation Award 2009 Washington State University McNair Achievement Program Fellowship 2008 Washington State University College of Sciences College of Science Undergraduate Student Research Mini-grant 2007 Washington State University Wiley College of Science Scholarship 2005 TEACHING EXPERIENCE University of California, Irvine Teaching Assistant Genetics: Dr.
David Camerini, Summer (Session I) 2012, 2013 Dr. Rahul Warrior, Dr. Olivier Cinqui, and Dr. Lee Bardwell Fall 2012 Cell Biology (Lab course) Dr.