Ethylene Oxide Exposure in U.S. Populations Residing Near Sterilization and Other Industrial Facilities: Context Based on Endogenous and Total Equivalent Concentration Exposures

• Published in: International journal of environmental research and public health Vol. 18; no. 2; p. 607
• Main Authors: Sheehan, Patrick J, Lewis, Ryan C, Kirman, Christopher R, Watson, Heather N, Winegar, Eric D, Bus, James S
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.01.2021; MDPI
• Subjects: COVID-19; Environmental Exposure; Environmental protection; Ethylene oxide; Ethylene Oxide - analysis; Ethylene Oxide - toxicity; Exposure; Geography; Health risks; Humans; Industrial plant emissions; Industrial plants; Manufacturing and Industrial Facilities; Metabolism; Population; Populations; Public health; Risk assessment; Sterilization; United States - epidemiology; United States Environmental Protection Agency; United States; United States > US; exposure contextualization; endogenous equivalent concentration; exposure metrics; total equivalent concentration; ethylene oxide; exposure science
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph18020607

Given ubiquitous human exposure to ethylene oxide (EO), regardless of occupation or geography, the current risk-specific concentrations (RSCs: 0.0001-0.01 ppb) from the U.S. Environmental Protection Agency (EPA) cancer risk assessment for EO are not useful metrics for managing EO exposures to the general U.S. population. The magnitude of the RSCs for EO are so low, relative to typical endogenous equivalent metabolic concentrations (1.1-5.5 ppb) that contribute ~93% of total exposure, that the RSCs provide little utility in identifying excess environmental exposures that might increase cancer risk. EO monitoring data collected in the vicinity of eight EO-emitting facilities and corresponding background locations were used to characterize potential excess exogenous concentrations. Both 50th and 90th percentile exogenous exposure concentrations were combined with the 50th percentile endogenous exposure concentration for the nonsmoking population, and then compared to percentiles of total equivalent concentration for this population. No potential total exposure concentration for these local populations exceeded the normal total equivalent concentration 95th percentile, indicating that excess facility-related exposures are unlikely to require additional management to protect public health.