Ambient particle radioactivity and gestational diabetes: A cohort study of more than 1 million pregnant women in Massachusetts, USA

Stefania Papatheodorou, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA. Electronic address: spapathe@hsph.harvard.edu.
Diane R. Gold, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital Harvard Medical School, Boston, MA 02115, USA.
Annelise J. Blomberg, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Michele Hacker, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Blair J. Wylie, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, MA, USA.
Weeberb J. Requia, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Emily Oken, Division of Chronic Disease Research Across the Lifecourse, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA; Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.
Abby F. Fleisch, Pediatric Endocrinology and Diabetes, Maine Medical Center, Portland, ME, USA; Center for Outcomes Research and Evaluation, Maine Medical Center Research Institute, Portland, ME, USA.
Joel D. Schwartz, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Petros Koutrakis, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.

Abstract

BACKGROUND: Exposure to ionizing radiation increases the risk of chronic metabolic disorders such as insulin resistance and type 2 diabetes. Internal ionizing radiation from inhaled radioactive aerosol may contribute to the associations between fine particulate matter (PM) and gestational diabetes mellitus (GDM). METHODS: We used the Massachusetts Registry of Vital Records to study 1,061,937 pregnant women from 2001 to 2015 with a singleton pregnancy without pre-existing diabetes. Gross β activity measured by seven monitors of the U.S. Environmental Protection Agency's RadNet monitoring network was utilized to represent ambient particle radioactivity (PR). We obtained GDM status from birth certificates and used logistic regression analyses adjusted for socio-demographics, maternal comorbidities, PM, temperature and relative humidity. We also examined effect modification by smoking habits. RESULTS: Ambient particle radioactivity exposure during first and second trimester of pregnancy was associated with higher odds of GDM (OR: 1.18 (95% CI 1.10 to 1.22). Controlling for PM did not substantially change the effects of PR on GDM. In women that reported being former or current smokers, the association between PR and GDM was null. In the full cohort, the overall effect of PM on GDM without adjusting for PR was not significant. CONCLUSION: This is the first population-based study to examine the association between particle radioactivity and gestational diabetes mellitus - one of the most common pregnancy-related diseases with lifelong effects for the mother and the fetus. This finding has important public health policy implications because it enhances our understanding about the toxicity of PR, a modifiable risk factor, which to date, has been considered only as an indoor and occupational air quality risk.