Pilot Study to Assess the Quantitative Dermal Transfer Efficiencies of Solids for Multiple Transfer Pathways
Pilot Study to Assess the Quantitative Dermal Transfer Efficiencies of Solids for Multiple Transfer Pathways
Dermal transfer efficiency has been defined as the amount of material that moves from one
 surface to another following contact. The investigators propose to measure dermal transfer
 efficiency for the following pathways: (1) object to skin, (2) skin to skin, (3) skin to
 mouth, (4) clothing to skin, (5) gloves to skin, and (6) air to skin. First, the quantitative
 dermal transfer will be measured for the two selected test substances (lead, Tinopal) for
 each of these six pathways. The relative quantities of dermal transfer will also then be
 compared between the different transfer pathways (e.g., is skin to skin transfer greater or
 less than clothing to skin transfer?). And second, the pattern of transfer will be
 characterized semi-quantitatively (e.g., does dermal transfer occur consistently and evenly
 to the skin from different reservoirs?).
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.