Bioavailability of polycyclic aromatic hydrocarbons (PAHs) from soil and hay matrices in lactating goats

This experiment was aimed at determining the bioavailability of three polycyclic aromatic hydrocarbons (PAHs) in goats: phenanthrene, pyrene, and benzo[a]pyrene. A Latin square design procedure was carried out involving three alpine lactating goats and three PAH-contaminated matrices (soil, hay, and oil as a control). Milk and urine samples were collected to assess PAH and hydroxy-PAH excretion kinetics and to compare the carry-over rates for the different matrices. PAHs were found to be excreted mainly in urine; metabolite concentrations were about 20 times higher in urine than in milk. 1-Hydroxypyrene was the major metabolite in both body fluids (8000 ng/mL urine and 450 ng/mL milk); it may be considered as a valuable indicator of the ruminant exposure to PAHs. Apparent absorption of PAHs estimated by the metabolite excretion in urine and milk reached 34% for pyrene from soil, and the bioavailability of soil-bound PAHs was found to be similar to the bioavailability of PAHs from the other matrices.