1. PAH depletion in weathered oil slicks estimated from modeled age-at-sea during the Deepwater Horizon oil spill.
- Author
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Montas, Larissa, Ferguson, Alesia C., Mena, Kristina D., Solo-Gabriele, Helena M., and Paris, Claire B.
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BP Deepwater Horizon Explosion & Oil Spill, 2010 , *OIL spill cleanup , *OIL spill management , *POLYCYCLIC aromatic hydrocarbons , *OIL spills , *CHEMICAL spills , *VAPOR pressure - Abstract
During time-periods oil slicks are in the marine environment (age-at-sea), weathering causes significant changes in composition and mass loss (depletion) of oil spill chemicals including the more toxic polycyclic aromatic hydrocarbons (PAHs). The goal of this study was to estimate the age-at-sea of weathered oil slicks using the oil spill module of the Connectivity Modeling System and to use this age to interpret PAH concentration measurements. Percent depletion (PD) for each measurement was computed as the percentage difference between the original and measured PAH concentration in the crude oil and weathered oil slicks, normalized upon the mass losses relative to hopane. Mean PD increased with estimated age-at-sea for all PAHs. Less PD was observed for alkylated than for parent PAHs, likely due to decreasing vapor pressure with increasing degree of alkylation. We conclude that estimated age-at-sea can be used to explain PAH depletion in weathered oil slicks. We propose PAH vapor pressure can be coupled with the model to expand capacity for predicting concentration distributions of individual parent and alkylated PAHs in weathered oil along the coastline. This new module will advance the science supporting oil spill response by providing more certain estimates of health risks from oil spills. [Display omitted] • Evaluated relationship between age-at-sea and PAH depletion. • PAH depletion increased with estimated age-at-sea. • PAH vapor pressure decreased with increasing alkylation. • A new module to predict PAH concentration distributions is recommended. • Improved oil spill response through better estimates of health risks. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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