Pilot Study to Assess the Quantitative Dermal Transfer Efficiencies of Solids for Multiple Transfer Pathways

Each of the six transfer pathways will be tested and measured in a controlled, ventilated
study chamber at the University of Minnesota's School of Public Health Industrial Hygiene
Laboratory. To test each pathway, human volunteers will perform repeated contact activities
using an identical protocol (e.g., identical number of contacts, type of material contacted,
measured pressure of contact, measured time of contact, measured temperature and humidity) so
that inter- and intra-individual variability can be characterized.

The qualitative and quantitative sampling methods that will be used have been developed,
tested, and published by researchers from the National Institute for Occupational Safety and
Health (NIOSH) and other institutions such as ASTM. Specifically, quantitative transfer
efficiencies will be measured using accepted wipe sampling protocols taken from several
papers in the peer-reviewed literature. Semi-quantitative transfer patterns will be measured
using fluorescent tracer intensity techniques that have also been presented in the
peer-reviewed literature. The skin surface wipe samples will be sent to an accredited
American Industrial Hygiene Association (AIHA) laboratory for analysis.

These sampling results will allow the investigators to report the measured quantitative
dermal transfer efficiencies of elemental metallic lead and Tinopal for each pathway in mass
per square surface area of skin, and also calculate the relative transfer efficiencies in
terms of percent transferred versus originally loaded. Fluorescent tracer maps will allow the
investigators to demonstrate the patterns of transfer for each pathway using intensity of the
tracer following transfer. Following this analysis, the investigators will then use the data
to better inform the relative importance of the pathways in the conceptual model with respect
to dermal exposure assessment and modeling efforts. These results are very important for
improving the quality of workplace dermal exposure assessments and techniques. The current
approaches are not well validated, and it is unknown if the results of existing dermal
exposure models are accurate. It is expected that the results of this study will help to
improve the protection of workers from certain dermal exposure hazards in the workplace by
providing better inputs to the existing dermal exposure models, since it is not possible to
collect exposure samples for each job task in the workplace.

Inclusion Criteria:

- Adult volunteers with healthy intact skin.

Exclusion Criteria:

- Children will be excluded from the study.

- Adults with a past history of dermal sensitization, skin allergy, or dermal irritation
or dermatitis because of the potential to have compromised barrier function in the
skin.

- Adults who are unwilling to follow protocol requirements.

- Adults who have a documented history of lead poisoning.

- Adults who have a concurrent contagious illness or other stressor which in the opinion
of the investigator may interfere with the subject's ability to perform the study's
requirements.

- Adults who have open wounds or otherwise compromised skin integrity on their hands.

- Adults who are pregnant or nursing.

- Adults who lack the capacity to provide informed voluntary consent to participate in
the study.