Bioavailability of plasticizers in dust and food after oral administration in pigs

摘要

Background: According to the US Environmental protection agency (US-EPA), infants have an unintended daily uptake of 60-100 mg dust. Dust contains among other things a various amount of pollutants. Especially phthalates are present in high amounts. This could pose a potential health risk. At the current state of knowledge, there is no information about the bioavailability of pollutants in the matrix dust. Therefore, in risk assessments, the bioavailability is assumed to be 100%. This could lead to an overestimation because in vitro digestions tests indicate that the bioaccessability of phthalates in house dust range only between 2.4%-32%. Phthalates are widely used as plasticizers in many consumer products e.g. food packaging, toys, clothing and personal care products. Phthalates are not chemically bound to the polymer matrix, so they can easily be released into the surrounding by leaching or migration. Humans are exposed to phthalates on a daily basis via ingestions, inhalations or dermal uptake. Phthalates act as endocrine disruptors and target mainly the reproductive system. They do not accumulate in the body and are rapidly metabolized and excreted via urine within 48 hours. Objectives: The oral bioavailability of certain Phthalates and Diisononylcyclohexa-1,2-dicarboxylat (DINCH) in house dust will be determined absolutely and relative to the bioavailability after intravenous administration or by ingestion. Methods: Eight 5-week old piglets were fed once with five different dust samples from daycare centers and one food sample. Additionally, the target compounds were given by intravenous injection. The urine was collected over a period of 38 hours. The metabolites were quantified in the urine by using an HPLC-MS/MS method. Results: The preliminary experiment (three piglets and three dust samples) showed a median uptake rate of 30% DEHP (range 24-43%) and 27% DINCH (range 23-31%) of the given dose. Those results indicated that the bioavailability is higher than in the in vitro digestion tests (DEHP: 2.24-12.6%) but also not 100%. The results of the main experiment are in progress.