ABILITY OF 16 PRIORITY PAHS TO BE PHOTOCYTOTOXIC TO A CELL-LINE FROM THE RAINBOW-TROUT GILL

Sixteen polycyclic aromatic hydrocarbons (PAHs) were screened for thei r ability to be photocytotoxic to a cell line from the rainbow trout g ill, RTgill-W1. PAHs could be divided into one of three groups: incapa ble of being photocytotoxic, able to be both photocytotoxic and direct ly cytotoxic, or capable of being only photocytotoxic. Photocytotoxici ty was distinct from direct cytotoxicity in that EC50 values were lowe r with the neutral red assay immediately after the PAH/UV treatment th an with alamar Blue or CFDA-AM, indicating a more specific action on l ysosomes. As well, in photocytotoxicity but not in direct cytotoxicity , the three assays showed increased impairment 24 h after treatment. M ost PAHs were found to be strictly photocytotoxic; however, only six c ompounds were photocytotoxic at concentrations theoretically achievabl e in water. When photocytotoxic PAHs were ranked relative to fluoranth ene to establish fluoranthene equivalent factors (FEFs), benzo[a]pyren e and benzo[g,h,i]perylene were found to be most potent. However, when the water solubility of each compound was taken into account in order to calculate the potential environmental photocytotoxic potency (PEPP ), fluoranthene and pyrene appeared to have the most potential to impa ct fish through photocytotoxicity. (C) 1998 Elsevier Science Ireland L td. All rights reserved.