How Fine Particulate Matter Modifies Preterm Birth Risks in Korea

How Fine Particulate Matter Modifies Preterm Birth Risks in Korea by Hyun Jin Choi BS, Utah State University, 2002 BS, Yonsei University, 2000 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Public Health Walden University August 2018 Abstract Despite the increasing interest in preterm birth risk associated with maternal exposure to the current level of fine particulate matter (PM2.5) in Korea, there is little information on differences in PM2.5 exposure and its impact on preterm birth. This study was designed to examine the effects of Korea’s air quality on preterm birth, including the possibility of moderation and mediation. This work was also designed to investigate manipulableDespite the increasing interest in preterm birth risk associated with maternal exposure to the current level of fine particulate matter (PM2.5) in Korea, there is little information on differences in PM2.5 exposure and its impact on preterm birth. This study was designed to examine the effects of Korea’s air quality on preterm birth, including the possibility of moderation and mediation. This work was also designed to investigate manipulable factors for PM2.5 exposure. The theoretical framework of this quantitative and observational study included the social ecological theory and systems theory. The conceptual framework of this partially ecologic and retrospective cohort study included the social ecological model and Rothman’s sufficient component cause model. Data of 19,371 Korean women who gave birth in 2015 were analyzed by logistic regression and multiple regression, including testing for moderation and mediation. An increase in PM2.5 exposure by 10 μg/m in the 3rd week before childbirth increased the likelihood of preterm birth by 6.52 times. Moderation and mediation by PM2.5 did not exist between sociodemographic factors and gestational age but existed between socioeconomic and energy policy factors and gestational age. The most influential factor for PM2.5 exposure was unemployment rate at the organizational level. These results show the need for socioeconomic interventions to reduce PM2.5 exposure more effectively. These findings indicate that prenatal care should be addressed with a socioeconomicand energy-policysensitive approach to lower preterm birth due to severe air pollution in Korea. This study has the potential to change people's perceptions of threats from PM2.5 exposure, which could lead to behavior changes. How Fine Particulate Matter Modifies Preterm Birth Risks in Korea by Hyun Jin Choi BS, Utah State University, 2002 BS, Yonsei University, 2000 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Public Health Walden University August 2018 Acknowledgments I would like to express my deepest gratitude to Dr. Cheryl Cullen, who led me with her strong leadership and extensive knowledge, motivated me to make progress in my doctoral dissertation and provided me with constructive feedback on how to improve my work, particularly with regard to the relevancy of research concepts to the profession and social change. I would like to thank Dr. Leslie Elliott, who shared her knowledge of the concepts of research and encouraged me to look at things from different perspectives. My special thanks to Dr. Mehdi Agha, who taught me Advanced Biostatistics at Walden University. Thanks to all professors at Walden University.