The development of a paper-based analytical device (PAD) for assessing personal exposure to particulate metals will be
presented. Human exposure to metal aerosols, such as those that occur in the mining, construction, and manufacturing
industries, has a significant impact on the health of our workforce, costing an estimated $10B in the U.S and causing
approximately 425,000 premature deaths world-wide each year. Occupational exposure to particulate metals affects
millions of individuals in manufacturing, construction (welding, cutting, blasting), and transportation (combustion, utility
maintenance, and repair services) industries. Despite these effects, individual workers are rarely assessed for their
exposure to particulate metals, due mainly to the high cost and effort associated with personal exposure measurement.
Current exposure assessment methods for particulate metals call for an 8-hour filter sample, after which time, the filter
sample is transported to a laboratory and analyzed by inductively-coupled plasma (ICP). The time from sample
collection to reporting is typically weeks and costs several hundred dollars per sample. To exacerbate the issue, method
detection limits suffer because of sample dilution during digestion. The lack of sensitivity hampers task-based exposure
assessment, for which sampling times may be tens of minutes. To address these problems, and as a first step towards
using microfluidics for personal exposure assessment, we have developed PADs for measurement of Pb, Cd, Cr, Fe, Ni,
and Cu in aerosolized particulate matter.