Modeling dermal exposure--an illustration for spray painting applications

This article presents a conceptual, mathematical model of dermal exposure resulting from aerosol deposition on human forearm hair. The model is applicable to exposure scenarios where dermal deposition is governed by aerosol impaction, interception, and diffusion mechanisms. The model employs filtration theory, single fiber efficiency equations, and a modified potential airflow approximation. The results are extended, using previously published results, for application to dermal deposition on the forearm during spray painting. The average (N = 8) predicted dermal deposition of 1,6-hexamethylene diisocyanate as collected on a 10-cm(2) tape strip is 108.9 (+/- 70.3) pmol, whereas field measurements indicated an average of 168.6 (+/- 82.0) pmol per strip. The corresponding measured average dermal flux was 3.63 pg/cm(2)s (+/- 1.34); the prediction was 2.24 pg/cm(2)sec (+/- 1.25). The study calls attention to the importance of body hair both for modeling and measuring dermal exposures.