Ethyl Benzene (EB) Exposure and Potential Health Effects From Natural Gas Extraction in Urban Areas (Urban Drilling)

Objective: To examine the presence of ethyl benzene (EB) in ambient air in residential areas experiencing natural gas extraction and processing (E&P) and identify potential health impacts. Background: Residential communities affected by “urban drilling” have raised concerns about potential health effects from exposure to toxic chemicals. This study examines ethyl benzene (EB) in ambient air in residential communities experiencing E&P operations and potential health impacts from EB exposure. Natural gas processing occurring at pad sites located in residential areas were identified as potential sources of EB emissions. Methodology: A meta-analysis was performed and articles related to health effects from EB exposure evaluated. Databases searched included: Pub-Med, Scopus, Science direct and TOXLINE. Keywords were ethyl benzene, health effects, occupational exposure, natural gas and ambient air. Initially, 500 articles on the health effects of EB were selected. Publication dates ranged from 1967 to 2014. Inclusion criteria were occupational exposure, health effects, ambient air and toxicological animal studies. Exclusion criteria were soil and groundwater contamination, and EB exposure from other sources like cigarette smoke. Retrieved abstracts were evaluated for relation to study focus. Fifty articles were selected and reviewed as full text. Results: Occupational studies of EB exposed workers in natural gas and petrochemical industries, confirmed multi-system toxic effects. Animal studies supported the findings. Adverse health effects included respiratory, cardiovascular, reproductive, hematologic, digestive/liver, excretory and endocrine impairment. Ambient air monitoring studies confirmed elevated levels of EB in residential communities experiencing urban drilling. Conclusion: Communities where natural gas E&P operations are occurring may experience occupational-like exposure to EB and elevated risk of adverse health effect when compared to other areas. Current literature on health effects from EB exposure is lacking and limited to occupational studies. Future studies examining occupational-like EB exposures in residential communities experiencing urban drilling are recommended.