Estimating dermal transfer from PCB-contaminated porous surfaces

Area of Science:

• Environmental Science
• Toxicology
• Occupational Health

Background:

• Assessing health risks from dermal contact with polychlorinated biphenyls (PCBs) on porous surfaces is difficult.
• Standard hexane wipe sampling may not accurately reflect actual PCB transfer during casual hand contact with contaminated surfaces.
• The relationship between hexane wipe results and direct dermal pickup from porous materials remains unclear.

Purpose of the Study:

• To develop and evaluate alternative wipe sampling methods that better simulate dermal PCB pickup from contaminated concrete.
• To compare the efficiency of different solvents and application techniques in mimicking casual hand contact.
• To provide a basis for more accurate estimation of dermal exposure to PCBs from porous surfaces.

Main Methods:

• Investigated PCB pickup from concrete using various wipe materials, solvents (hexane, oil, saline), and application techniques (rubbing vs. no rubbing).
• Compared results from alternative methods to standard hexane-wetted wipe sampling with rubbing.
• Quantified the percentage of PCB pickup relative to the standard hexane procedure.

Main Results:

• Dry and oil-wetted wipes without rubbing collected <1% of PCBs compared to the standard method.
• Saline-wetted wipes without rubbing collected 2.5%, while with rubbing, they collected approximately 12%.
• Alternative wiping methods, particularly saline with rubbing, more closely mimicked dermal contact than standard hexane wipes.

Conclusions:

• Standard hexane wipe sampling may underestimate dermal PCB exposure from porous surfaces.
• Alternative wipe sampling protocols using saline and rubbing offer a more realistic assessment of dermal pickup.
• These findings can improve risk assessments for sites contaminated with PCBs, particularly concrete structures.