Karen Y. Richter

Investigation of Dermal Contact with Soil in Controlled Trials

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 article 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 childrens play. Soil contact on hands, forearms, lower legs, and faces was examined using both fluoro-metric and gravimetric measurements. Results provide information on pre- and postactivity loadings, the extent of contact associated with the selected activities, and the effects of clothing, activity duration, and soil moisture. Preactivity 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 w...

Investigation of the influence of oil on soil adherence to skin

Dermal contact with contaminated soils may be a significant route of human exposure to toxic substances under some circumstances. Soil adherence to skin is an important determinant of such exposures, but factors influencing soil adherence are generally not well characterized. Petroleum hydrocarbons are often found in contaminated soils at relatively high concentrations. Results of an investigation of the influence of motor oil on soil adherence to skin are reported here. Studies were conducted at three oil concentrations (0, 1, and 10% by weight) under wet and dry conditions in three different soil types. Only two of six soil/moisture combinations showed consistently increasing adherence with increasing oil content. Overall, an increase was found in wet, but not dry soils. The results indicate that high concentrations of petroleum contaminants can increase the dermal adherence of soil, but that the magnitude of the effect is likely to be modest.