Methamphetamine Residue Dermal Transfer Efficiencies from Household Surfaces

Abstract

Methamphetamine contamination from illegal production operations poses a potential health concern for emergency responders, child protective services, law enforcement, and children living in contaminated structures. The objective of this study was to evaluate dermal transfer efficiencies of methamphetamine from contaminated household surfaces. These transfer efficiencies are lacking for methamphetamine, and would be beneficial for use in exposure models. Surfaces were contaminated using a simulated smoking method in a stainless steel chamber. Household surfaces were carpet, painted drywall, and linoleum. Dermal transfer efficiencies were obtained using cotton gloves for two hand conditions, dry or saliva moistened (wet). In addition, three contact scenarios were evaluated for both hand conditions: one, two, or three contacts with contaminated surfaces. Dermal transfer efficiencies were calculated for both hand conditions and used as inputs in a Stochastic Human Exposure and Dose Simulation model (SHEDS-Multimedia, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, N.C.). Results of this study showed that average dermal transfer efficiencies of methamphetamine ranged from 11% for dry hands to 26% for wet hands. There was a significantly higher wet transfer as compared to dry transfer for all surfaces. For wet hands, dermal transfer depended on surface type with higher transfer from carpet and linoleum as compared to drywall. Based on our estimates of dermal transfer efficiency, a surface contamination clearance level of 1.5 μg/100 cm² may not ensure absorbed doses remain below the level associated with adverse health effects in all cases. Additional dermal transfer studies should be performed using skin surrogates that may better predict actual skin transfer.

Keywords:

• Methamphetamine
• dermal transfer efficiency
• exposure assessment
• SHEDS-Multimedia
• surface contamination clearance level

ACKNOWLEDGMENTS

This project was supported by Grant #2009CKWX0503 awarded by the U.S. Department of Justice, Office of Community Oriented Policing Services. The opinions contained herein are those of the authors and do not necessarily represent the official position or policies of the U.S. Department of Justice. References to specific companies, products, or services should not be considered an endorsement by the authors or the U.S. Department of Justice. Rather, the references are illustrations to supplement discussion of the issues.

 We would also like to acknowledge assistance from the North Metro Task Force and the City of Thornton, Colorado, Police Department in obtaining the street-manufactured me- thamphetamine utilized in these studies. We would also like to thank Geoffrey S. Plumlee and Greg Meeker of the United States Geological Survey for the electron micrographs of the methamphetamine.