Accuracy of professional judgments for dermal exposure assessment using deterministic models

Abstract

The accuracy of exposure judgments, particularly for scenarios where only qualitative information is available or a systematic approach is not used, has been evaluated and shown to have a relatively low level of accuracy. This is particularly true for dermal exposures, where less information is generally available compared to inhalation exposures. Relatively few quantitative validation efforts have been performed for scenarios where dermal exposures are of interest. In this study, a series of dermal exposure judgments were collected from 90 volunteer U.S. occupational health practitioners in a workshop format to assess the accuracy of their judgments for three specific scenarios. Accuracy was defined as the ability of the participants to identify the correct reference exposure category, as defined by the quantitative exposure banding categories utilized by the American Industrial Hygiene Association (AIHA^®). The participants received progressively additional information and training regarding dermal exposure assessments and scenario-specific information during the workshop, and the relative accuracy of their category judgments over time was compared. The results of the study indicated that despite substantial education and training in exposure assessment generally, the practitioners had very little experience in performing dermal exposure assessments and a low level of comfort in performing these assessments. Further, contrary to studies of practitioners performing inhalation exposure assessments demonstrating a trend toward underestimating exposures, participants in this study consistently overestimated the potential for dermal exposure without quantitative data specific to the scenario of interest. Finally, it was found that participants were able to identify the reference or “true” category of dermal exposure acceptability when provided with relevant, scenario-specific dermal and/or surface-loading data for use in the assessment process. These results support the need for additional training and education of practitioners in performing dermal exposure assessments. A closer analysis of default loading values used in dermal exposure assessments to evaluate their accuracy relative to real-world or measured dermal loading values, along with consistent improvements in current dermal models, is also needed.

KEYWORDS:

• Dermal absorption
• dermal loading
• exposure modeling
• skin
• workplace exposure

Acknowledgments

The authors would like to thank Dr. Sheryl Milz and Dr. Daniel Drolet for their contributions to the data collection efforts for this study.

Data availability statement

The data supporting this study’s findings are either included in this published article or the supplementary materials will be made available upon reasonable request to the corresponding author. Data that could compromise the privacy of research participants will not be made available.

Additional information

Funding

No external funding was received for this study. The author JS is a current employee of Insight Exposure and Risk Sciences, a consulting firm that provides scientific advice to entities including governments, corporations, law firms, and various scientific/professional organizations. JS has previously served as a testifying expert in the areas of exposure and risk assessment.