A Risk Evaluation of Metals in Crude Oils

All crude oils contain trace quantities of naturally occurring metals, however, few data have been published on the specific metal content of crude oils. In this study, the metals concentrations in 26 crude oils from North America, South America, the North Sea, the Middle East, and Far East Asia were determined. The crude oils represent both a range of geographical production areas and a range of crude oil types, with the oils having API gravity values ranging from 12° to 46°. The concentrations of 18 metals were determined, and the potential human health risks associated with the metals were evaluated, assuming standard exposure scenarios. The potential for ecological impact was also evaluated by comparing the metal concentrations to ecological soil screening level benchmarks. The results indicate that many metals are present at such low levels that there is no need to consider them as chemicals of concern for purposes of site characterizations and risk assessments at sites where accidental and/or historical crude oil releases have occurred.