Mineral oil in human tissues, Part I: Concentrations and molecular mass distributions

Of 37 subjects aged 25-91 y (mean 67 y), mineral oil hydrocarbons were measured in subcutaneous abdominal fat tissue, mesenteric lymph nodes (MLN), spleen, liver and lung, for some of them also in kidney, heart and brain. No mineral oil aromatic hydrocarbons (MOAN) were detected. The mean concentration of mineral oil saturated hydrocarbons (MUSH) in the mesenteric lymph nodes was 223 mg/kg, in liver 131 mg/kg, in fat tissue 130 mg/kg, in spleen 93 mg/kg and in lung 12 mg/kg. They were clearly lower in kidney, heart and brain. The maxima, found in MILN and spleen, were 1390 and 1400 mg/kg, respectively. For a quarter of the subjects a total amount of MOSH in the body above 5 g was calculated. The MOSH composition in the fat tissue and the MLN appeared virtually identical and varied little between the subjects. It was centered on the n-alkanes C-23-C-24, ranged from C-16 to C-35 and included hydrocarbons of plant origin. The MUSH in spleen and liver had almost the same composition for a given subject, but varied somewhat between subjects. They were centered between C-25 and C-27, ranged from C-18 to beyond C-45 and were without hydrocarbons of plant origin. Part of the MUSH seem to be strongly accumulated, resulting in far higher concentrations in human tissues related to exposure than observed in shorter term animal experiments. The composition of the accumulated MUSH does not support that Class I mineral oils, sometimes termed food grade, are less accumulated in the human body than Class H and III oils, which questions the present classification. (C) 2014 Elsevier Ltd. All rights reserved.