Impact of Clothing on Dermal Exposure to Phthalates: Observations and Insights from Sampling Both Skin and Clothing

Abstract

Clothing can either retard or accelerate dermal exposure to phthalates. To investigate the impact of clothing on dermal exposure to six phthalates (DMP/DEP/DiBP/DnBP/BBzP/DEHP) in real environments, two sets of experiments have been conducted: (1) Skin wipes were collected from 11 adults to examine the phthalate levels on both bare-skin (hand/forehead) and clothing-covered body locations (arm/back/calf); (2) Five adults were asked to wear just-washed jeans for 1 day (1(st) experiment), 5 days (2(nd) experiment), and 10 days (3(rd) experiment). Phthalate levels on their legs were measured on selected days during the wearing period, and phthalate levels in the jeans were measured at the end of each experiment and again after washing. Measured phthalate levels on body locations covered by clothing were lower than those on uncovered locations, but still substantial. Dermal uptake would be underestimated by a factor of 2 to 5 if absorption through body locations covered by clothing were neglected. Phthalate levels in the jeans and on the legs increased with the wearing time. However, the levels in the jeans and on the legs were not strongly correlated, indicating that other pathways, e.g, contact with bedding or bedclothes, likely contribute to the levels on the legs. The efficiency with which laundering washing removed phthalates from the jeans increased with decreasing Kow; median values ranged from very low (<5%) for DEHP to very high (∼75%) for DMP.

Dermal uptake of phthalates from clothing: Comparison of model to human participant results

“…However, <20% of DnBP was retained on the clothing after washing. Based on the findings of Gong et al 25 and Saini et al 26 and the fact that the clothing in Morrison et al 12 was washed and hot-air tumble-dried, we anticipate that most of the DEP and DnBP was removed prior to the 9-day exposure interval. In general, incomplete removal of SVOCs after laundering will increase the initial concentration in the fabric, thereby hastening the approach to equilibrium during the launderwear interval and potentially increasing exposure.…”

“…However, <20% of DnBP was retained on the clothing after washing. Based on the findings of Gong et al . and Saini et al .…”

“…An important assumption applied in these simulations is that SVOCs are removed completely after laundering. Gong et al . found that approximately 80% and 30% of DEP and DnBP, respectively, were removed in laundering cotton jeans.…”

“…SVOCs are removed completely after laundering. Gong et al 25 found that approximately 80% and 30% of DEP and DnBP, respectively, were removed in laundering cotton jeans. Larger molecular weight phthalates were removed less efficiently, and they observed an inverse relationship between removal fraction and log 10 K ow .…”

“…Larger molecular weight phthalates were removed less efficiently, and they observed an inverse relationship between removal fraction and log 10 K ow . However, the laundered clothing described in Gong et al 25 was dried by hanging in the air. Had the clothing been tumble-dried in a hot-air dryer, the removal efficiency of DEP and DnBP would likely have been higher.…”