Greenhouse Studies
Kissel, J.C., Shirai, J.H., Richter, K.Y., and Fenske, R.A. (1998).
"Investigation of Dermal Contact with Soil in Controlled Trials,"
J. Soil Contam. 7(6):737-752.
Abstract
A series of laboratory, greenhouse, and field experiments have been conducted
at the University of Washington to improve the empirical grounding of dermal/soil
pathway risk calculations. This paper presents results from controlled trials,
conducted in a greenhouse, in which volunteers engaged in activities in
soil amended with a fluorescent marker. Activities included transplanting
of bedding plants and laying of pipe by adults and children's play. Soil
contact on hands, forearms, lower legs, and faces was examined using both
fluorometric and gravimetric measurements. Results provide information on
pre- and post-activity loadings, the extent of contact associated with the
selected activities, and the effects of clothing, activity duration, and
soil moisture. Pre-activity loadings were consistent with previously reported
observations. Following activity, skin coverage was found to be substantially
incomplete except on hands. Local soil loadings may therefore deviate markedly
from mean values obtained by washing skin surfaces. A protective effect
of clothing was observed but may reflect the relatively short duration of
the experiments and the use of freshly laundered clothing. No significant
trend in soil loading with exposure duration was found although some evidence
of increasing surface area involvement with time was observed. Finally wet
soil activities produced consistently higher loadings on volunteers' hands
than dry soil activities.
