Quantitative Risk Model for Polycyclic Aromatic Hydrocarbon Photoinduced Toxicity in Pacific Herring Following theExxon ValdezOil Spill

Abstract

Phototoxicity occurs when exposure to ultraviolet radiation increases the toxicity of certain contaminants, including polycyclic aromatic hydrocarbons (PAHs). This study aimed to (1) develop a quantitative model to predict the risk of PAH phototoxicity to fish, (2) assess the predictive value of the model, and (3) estimate the risk of PAH phototoxicity to larval and young of year Pacific herring (Clupea pallasi) following the Exxon Valdez oil spill (EVOS) in Prince William Sound, Alaska. The model, in which median lethal times (LT50 values) are estimated from whole-body phototoxic PAH concentrations and ultraviolet A (UVA) exposure, was constructed from previously reported PAH phototoxicity data. The predictive value of this model was confirmed by the overlap of model-predicted and experimentally derived LT50 values. The model, along with UVA characterization data, was used to generate estimates for depths of de minimiz risk for PAH phototoxicity in young herring in 2003/2004 and immediately following the 1989 EVOS, assuming average and worst case conditions. Depths of de minimiz risk were estimated to be between 0 and 2 m deep when worst case UVA and PAH conditions were considered. A post hoc assessment determined that <1% of the young herring population would have been present at depths associated with significant risk of PAH phototoxicity in 2003/2004 and 1989.

Co‐exposure to sunlight enhances the toxicity of naturally weathered Deepwater Horizon oil to early lifestage red drum (Sciaenops ocellatus) and speckled seatrout (Cynoscion nebulosus)

“…All calculated tPAH 50 LC50s (0.18-5.78 mg /L) in the present study are within the lower range of PAH concentrations (0-84.8 mg/L) reported in the Deepwater Horizon spill area [29]. Deepwater Horizon spill oil, report total PAH median effective concentration (EC50) or LC50 values that are within an order of magnitude of those observed in the red drum and speckled seatrout tests [11,12,16,20]. (A) Mean percentage of mortality AE 1 standard error of larval speckled seatrout exposed to slick A high-energy water-accommodated fraction (HEWAF) and 1 of 3 ultraviolet (UV) treatments.…”

“…Photo-induced toxicity is the phenomenon in which a compound exhibits increased toxicity in the presence of certain light wavelengths [5]. The photo-induced toxicity of PAHs to aquatic species is well documented in the literature [5,6,11,[15][16][17]. The photo-induced toxicity of PAHs to aquatic species is well documented in the literature [5,6,11,[15][16][17].…”

The role of biomarkers in the assessment of aquatic ecosystem health

“…Incardona et al 2012; Sellin Jefferies et al 2013). Biomarker type responses were extensively used to assess these potential impacts.…”

Acute photo‐induced toxicity and toxicokinetics of single compounds and mixtures of polycyclic aromatic hydrocarbons in zebrafish

“…The potential for photo‐induced toxicity is closely tied to the dose of UV radiation to the system and can be modulated by aquatic system properties related to water transparency and humic content. When UV radiation enters aquatic systems, the photo‐induced toxicity adverse outcome pathway becomes an acute exposure mechanism in which toxicity is related to the internal dose of the PAH in the organism, the intensity of the UV radiation, and the duration of the UV + PAH exposure . Photo‐induced toxicity occurs when PAHs with a specific molecular structure absorb energy from UV radiation and become excited, causing the outer orbital electrons to be raised to a higher molecular energy orbital.…”

“…A handful of studies have addressed the toxicity of mixtures containing phototoxic components in a variety of organisms (in the oligochaete Lumbriculus variegates , the marine amphipod Rhepoxynius abronius , and in the marine diatom Phaeodactylum tricornutum ) . Recently, this approach was used to assess retrospective and contemporary phototoxic PAH risks to fish due to the Exxon Valdez oil spill in Prince William Sound, Alaska, USA .…”