Photoinduced Toxicity of Fluoranthene to Northern Leopard Frogs (Rana Pipiens)

Abstract

Rana pipiens larvae (96-118 h old) were exposed for 48 h in a flow-through system to clean water or five concentrations (0.89, 2.18, 6.99, 12.0, and 30.6 g/L) of the phototoxic polycyclic aromatic hydrocarbon (PAH) fluoranthene. Following this uptake period, the larvae were divided into four groups: one for immediate tissue residue analysis, a second for residue analysis following 48 h of depuration in clean water, and two for a 48-h exposure in clean water to ultraviolet (UV) light at two different levels. At the highest treatment, mean (ϮSD) UVA (310-390 nm) intensity was 8.12 Ϯ 0.19 ϫ 10 2 W/cm 2 , whereas at a lower treatment the UVA intensity was 4.45 Ϯ 0.05 ϫ 10 2 W/cm 2 . Larval frogs bioaccumulated fluoranthene in direct proportion to the water exposure concentrations, with initial whole-body PAH concentrations of 1.48, 3.53, 4.85, 11.3, and 18.7 g/g at the five treatment levels. No mortality of the animals occurred during the 48-h uptake phase. When the frogs were placed in clean water, the fluoranthene was rapidly depurated, with up to 80% lost in 48 h. Exposure to UV light following fluoranthene exposure significantly enhanced toxicity of the PAH. Median time to death decreased as the product of UVA light intensity and fluoranthene body residue increased. For larval R. pipiens, sufficient tissue residues of fluoranthene were bioaccumulated within 48 h, at water exposure concentrations in the range of 2 to 10 g/L, to be lethal when combined with a UVA exposure simulating a fraction of summertime, midday sunlight in northern latitudes.

Toxicity of coal-tar pavement sealants and ultraviolet radiation to Ambystoma Maculatum

“…Tadpoles of northern leopard frogs (Rana pipiens) experienced similar results when they were exposed to 30.6 lg/L of fluoranthene and 250 lg/L of anthracene. When tadpoles were exposed to UV radiation, mortalities increased (Kagan et al 1984;Monson et al 1999). In our experiment, maximal aqueous concentrations of benzo(a)pyrene (17 lg/L), fluoranthene (13 lg/L) and anthracene (65 lg/L) were below these toxic concentrations.…”

“…Amphibians can bioaccumulate PAHs (Grinfield et al 1986;Vojinovic-Miloradov et al 1996) but there is evidence that amphibians can develop an equilibrium in body concentrations after several days of exposure (Garrigues et al 2004). Oxidation and UV radiation can degrade parent PAHs and either make them less toxic or increase their toxicity by many times (Monson et al 1999, Albers 2003. For example, exposure of PAHs to ultraviolet (280-400 nm) radiation has increased toxicity by more than 100 times in bullfrogs (Rana catesbeiana) and the Spanish ribbed newt (Pleurodeles waltl) (Fernandez and l'Haridan 1992).…”

Environmental levels of ultraviolet light potentiate the toxicity of sulfonamide antibiotics in Daphnia magna

“…That is, the photochemical effects of a compound depend on the dose (intensity · time) and not on intensity. This law has been supported by many reports (Ankley et al 1995;Monson et al 1999;Weinstein 2002), and is usually also assumed for complex photobiological reactions. It is possible that the intensity we employed in the pulsed UVB exposure may have exceeded the threshold level for the defense and recovery mechanisms in D. magna.…”

Uptake and Elimination of Naphthalene from Liver, Lung, and Muscle Tissue in the Leopard frog (Rana pipiens)

“…In that study, 62% of the accumulated pyrene was metabolized and/or eliminated in 12 hours. Monson et al [15] showed that Rana pipiens larvae eliminated 80% of accumulated fluoranthene after a 48-hour recovery period. These time frames are fairly rapid for PAHs with high molecular weights and lower water solubilities.…”