GuLF DREAM: A Model to Estimate Dermal Exposure Among Oil Spill Response and Clean-up Workers

Melanie Gorman Ng; John W Cherrie; Anne Sleeuwenhoek; Mark Stenzel; Richard K Kwok; Lawrence S Engel; Jennifer M Cavallari; Aaron Blair; Dale P Sandler; Patricia Stewart

doi:10.1093/annweh/wxz037

GuLF DREAM: A Model to Estimate Dermal Exposure Among Oil Spill Response and Clean-up Workers

Ann Work Expo Health. 2022 Apr 7;66(Supplement_1):i218-i233. doi: 10.1093/annweh/wxz037.

Authors

Melanie Gorman Ng^{1

2}, John W Cherrie^{1

3}, Anne Sleeuwenhoek¹, Mark Stenzel⁴, Richard K Kwok⁵, Lawrence S Engel^{5

6}, Jennifer M Cavallari⁷, Aaron Blair⁸, Dale P Sandler⁵, Patricia Stewart⁹

Affiliations

¹ Centre for Human Exposure Science, Institute of Occupational Medicine, Research Avenue North, Edinburgh, EH14 4AP, UK.
² School of Population and Public Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
³ Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot Watt University, Edinburgh EH14 4AS, UK.
⁴ Exposure Assessment Applications, LLC, Arlington, VA 22207, USA.
⁵ Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA.
⁶ Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
⁷ Department of Community Medicine, University of Connecticut School of Medicine, Farmington, CT 06032, USA.
⁸ Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, MD 27709, USA.
⁹ Stewart Exposure Assessments, LLC, Arlington, VA 22207, USA.

Abstract

Tens of thousands of individuals performed oil spill response and clean-up (OSRC) activities following the 'Deepwater Horizon' oil drilling rig explosion in 2010. Many were exposed to oil residues and dispersants. The US National Institute of Environmental Health Sciences assembled a cohort of nearly 33 000 workers to investigate potential adverse health effects of oil spill exposures. Estimates of dermal and inhalation exposure are required for those individuals. Ambient breathing-zone measurements taken at the time of the spill were used to estimate inhalation exposures for participants in the GuLF STUDY (Gulf Long-term Follow-up Study), but no dermal measurements were collected. Consequently, a modelling approach was used to estimate dermal exposures. We sought to modify DREAM (DeRmal Exposure Assessment Method) to optimize the model for assessing exposure to various oil spill-related substances and to incorporate advances in dermal exposure research. Each DREAM parameter was reviewed in the context of literature published since 2000 and modified where appropriate. To reflect the environment in which the OSRC work took place, the model treatment of evaporation was expanded to include vapour pressure and wind speed, and the effect of seawater on exposure was added. The modified model is called GuLF DREAM and exposure is estimated in GuLF DREAM units (GDU). An external validation to assess the performance of the model for oils, tars, and fuels was conducted using available published dermal wipe measurements of heavy fuel oil (HFO) and dermal hand wash measurements of asphalt. Overall, measured exposures had moderate correlations with GDU estimates (r = 0.59) with specific correlations of -0.48 for HFO and 0.68 for asphalt. The GuLF DREAM model described in this article has been used to generate dermal exposure estimates for the GuLF STUDY. Many of the updates made were generic, so the updated model may be useful for other dermal exposure scenarios.

Keywords: Deepwater Horizon; GuLF STUDY; dermal exposure; dermal exposure modelling; determinants of exposure; exposure assessment.

Abstract

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