Contaminated soils (III): in vitro dermal absorption of ethylene glycol and nonylphenol in human skin

Human Hair, Baltic Grey Seal (Halichoerus grypus) Fur and Herring Gull (Larus argentatus) Feathers as Accumulators of Bisphenol A and Alkylphenols

The purpose of the study was to determine the concentration of bisphenol A (BPA), 4-tert-octylphenol (OP), and 4-nonylphenol (NP), in human hair, the fur of Baltic grey seals and the feathers of herring gulls. Hair was collected from 42 volunteers, while grey seal fur (n = 17) came from the seal centre in Hel (Marine Station of Institute of Oceanography, University of Gdansk) and gull covert feathers (n = 26) were collected from dead herring gulls along the Southern Baltic coast. Assays of phenol derivatives were conducted using the high performance liquid chromatography with fluorescence detection technique. In human hair, the mean BPA concentration amounted to 411.2 ng g^-1 dw, OP 131.2 ng g^-1 dw, NP 4478.4 ng g^-1 dw, in seal fur BPA 67.5 ng g^-1 dw, OP 62.8 ng g^-1 dw, NP 39.1 ng g^-1 dw, and in feathers BPA 145.1 ng g^-1 dw, OP 162.0 ng g^-1 dw, NP 37.7 ng g^-1 dw. The increase of the analysed EDCs in hair was significantly influenced by diet rich in products of marine origin, as well as hair colouring, heating up food in plastic containers, using home cleaning products without protective gloves and wearing newly purchased clothes without washing them first. The concentration of phenol derivatives in seal fur was influenced solely by the uniform diet rich in fish. In birds, the feeding area during molting significantly influenced the concentration of BPA, OP and NP found in covert feathers.

In vitro dermal absorption of di(2-ethylhexyl) adipate (DEHA) in a roll-on deodorant using human skin

In vitro dermal absorption experiments were conducted using a roll-on deodorant that contains 1.56% di(2-ethylhexyl) adipate (DEHA), a plasticizer widely used in consumer products. Human skin specimens were fitted in Bronaugh flow-through Teflon diffusion cells. The diffusion cells were maintained at 32 °C to reflect the skin temperature. Two amounts (low dose: 5 mg of the product; high dose: 100 mg) were applied, in triplicate, each on four different human skins. DEHA was determined in the receiver solution at 6-h intervals, using headspace solid-phase microextraction gas chromatography-mass spectrometry (GC-MS). After 24 h, the experiment was terminated and masses of DEHA in the skin depot, skin wash, and upper and lower chambers of the diffusion cell were determined. A significant portion of applied DEHA, 28% in the low amount application and 34% in the high one, was found in the skin depot. In comparison, only 0.04% and 0.002% of applied DEHA were found in the receiver solutions for the low and high doses, respectively. Under our experimental conditions, an apparent steady-state flux of low DEHA mass penetrating from skin into the receiver solution was observed with a penetration rate of 2.2 ng/cm(2)/h for both the low and high doses. The average mass recovery was 81% for the low dose application and 56% for the high dose.

A novel "by difference" method for assessing dermal absorption of polycyclic aromatic hydrocarbons from soil at federal contaminated sites

A highly precautionary cost-effective method for estimating dermal absorption using data from 24-h skin soap washes from in vitro dermal absorption tests in Bronaugh flow-through diffusion cells with human skin is reported. Skin was dosed with 16 U.S. Environmental Protection (EPA) priority polycyclic aromatic hydrocarbons (PAH) applied in mixture each at 2 μg/ml (ppm) in acetone without soil. Concurrent tests were conducted with an unspiked aqueous suspension of PAH-contaminated soil obtained from a Canadian federal contaminated site. Percentage dermal absorption was estimated "by difference" from the applied dose and that detected by high-performance liquid chromatography (HPLC) in 24-h skin soap washes. The dermal absorption for 11 PAH ranged from 71 to 88.3% without and with soil, respectively. Lower absorption was found for 5 PAH in soil, in the range of 26.4 to 60.8%. Data could not be corrected for evaporative loss due to inconsistent data from Tenax adsorbent. Corroboratory gas chromatography/mass spectroscopy (GC/MS) tests are needed. Previously published in vitro data from the authors' laboratory supported use of the "by difference" method.