Metabolism and excretion rates of parent and hydroxy-PAHs in urine collected after consumption of traditionally smoked salmon for Native American volunteers

Few studies have been published on the excretion rates of parent polycyclic aromatic hydrocarbons (PAHs) and hydroxy-polycyclic aromatic hydrocarbons (OH-PAHs) following oral exposure. This study investigated the metabolism and excretion rates of 4 parent PAHs and 10 OH-PAHs after the consumption of smoked salmon. Nine members of the Confederated Tribes of the Umatilla Indian Reservation consumed 50 g of traditionally smoked salmon with breakfast and five urine samples were collected during the following 24 h. The concentrations of OH-PAHs increased from 43.9 μg/g creatinine for 2-OH-Nap to 349 ng/g creatinine for 1-OH-Pyr, 3 to 6 h post-consumption. Despite volunteers following a restricted diet, there appeared to be a secondary source of naphthalene and fluorene, which led to excretion efficiencies greater than 100%. For the parent PAHs that were detected in urine, the excretion efficiencies ranged from 13% for phenanthrene (and its metabolite) to 240% for naphthalene (and its metabolites). The half-lives for PAHs ranged from 1.4 h for retene to 3.3 h for pyrene. The half-lives for OH-PAHs were higher and ranged from 1.7 h for 9-OH-fluorene to 7.0 h for 3-OH-fluorene. The concentrations of most parent PAHs, and their metabolites, returned to the background levels 24 h post-consumption.