RoseyFields conducted a comprehensive environmental investigation and human health risk assessment to evaluate fugitive and stack emissions of ethylene oxide (EtO) from a commercial medical sterilization facility. Ethylene oxide is a known human carcinogen and a volatile hazardous air pollutant commonly utilized to sterilize medical equipment. Our team was tasked with characterizing the historical release of these unmitigated emissions into the surrounding environment over a multi-year period to determine the potential impacts on local air quality and public health. To accurately reconstruct the facility’s emission profile, we evaluated historical purchasing records, operational practices, and the efficacy of available emission control technologies.
To quantify the inhalation exposure pathway, we evaluated the transport and dispersion of the chemical of concern using advanced environmental modeling techniques. Our team performed comprehensive air dispersion modeling utilizing the regulatory-approved AERMOD system, incorporating pre-processed meteorological data, local terrain characteristics, and facility-specific source terms such as stack parameters and estimated emission rates. By modeling these atmospheric dispersion patterns, we were able to calculate annual average ground-level concentrations of the contaminant and perform a rigorous cancer risk assessment following standardized environmental risk assessment methodologies and inhalation unit risk factors.
Based on the air dispersion modeling results, RoseyFields successfully identified and characterized the potential exposure class within the surrounding community. We evaluated the spatial extent of the contamination by mapping concentration isopleths and utilizing complex multi-scale receptor grids, which included both dense localized grids and discrete receptor points representing nearby residential areas. This approach allowed our team to visually and quantitatively define the geographic footprint of elevated cancer risks, ultimately providing a clear scientific determination of the affected population exposed to hazardous ambient air emissions exceeding acceptable regulatory health thresholds.
