Systematic Evidence Map of the Epidemiological Evidence for Health Effects of Ethylbenzene

Background & Aim: Ethylbenzene is an aromatic hydrocarbon widely used in consumer and industrial applications, including as styrene feedstock and in paints, glues, and fuels. Given that ethylbenzene is one of the most highly emitted hazardous air pollutants, it is relevant to survey the available literature to understand potential adverse health effects. Here, we utilize a systematic evidence map (SEM) approach to identify epidemiological studies of ethylbenzene exposure and characterize aspects of the evidence base that may support human health hazard identification. Methods: We developed a Populations, Exposures, Comparators, and Outcomes (PECO) statement to guide our SEM. Searches were conducted in PubMed, Web of Science, and selected grey literature sources. DistillerSR was used to identify PECO-relevant human studies and extract study details. The results are displayed in interactive Tableau® dashboards. Results: Over 40 epidemiological studies, including cross-sectional, case-control, cohort, and controlled trials, met the PECO criteria. Study participants included samples of the general population (adults), occupational populations, and children/infants. Most studies evaluated exposure to ethylbenzene through air monitoring or modeling, while fewer studies characterized exposure using biomarkers. Immune and respiratory outcomes were the two most commonly evaluated health effects across all study types. Other commonly assessed health effects included sensory, ocular, hematology, and developmental effects. Conclusions: Through the SEM, we identified and categorized numerous studies documenting a total of >10 organ systems potentially adversely affected by ethylbenzene exposure. The epidemiological data for ethylbenzene are suitable to inform human health hazard identification. Data gaps can be used to prioritize future research needs. Key words: ethylbenzene; systematic evidence map *Disclaimer: The views expressed in this abstract are those of the authors and do not necessarily reflect the views or policies of the U.S. EPA.