Predicting phototoxicity of alkylated PAHs, mixtures of PAHs, and water accommodated fractions (WAF) of neat and weathered petroleum with the phototoxic target lipid model

2018 ◽  
Vol 37 (8) ◽  
pp. 2165-2174 ◽  
Author(s):  
Solmaz Marzooghi ◽  
Bryson E. Finch ◽  
William A. Stubblefield ◽  
Dominic M. Di Toro
Keyword(s):  
Water Accommodated Fractions ◽  
Alkylated Pahs ◽  
Target Lipid Model

Changes in chemical composition and copepod toxicity during petroleum photooxidation

2022 ◽  
Author(s):  
Samuel Katz ◽  
Haining Chen ◽  
David Fields ◽  
Erin Beirne ◽  
Phoebe Keyes ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Oil Spill ◽  
Aromatic Hydrocarbons ◽  
Initial Phase ◽  
Water Solubility ◽  
Deepwater Horizon ◽  
Water Accommodated Fractions ◽  
Polycyclic Aromatic ◽  
Target Lipid Model ◽  
Control Samples

Photoproducts can be formed rapidly in the initial phase of a marine oil spill. However, their toxicity is not well understood. In this study, oil was irradiated, chemically characterized, and tested for toxicity in three copepod species (A. tonsa, T. longicornis, C.finmarchicus). Irradiation led to a depletion of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in oil residues, along with an enrichment in aromatic and aliphatic oil photoproducts. Target lipid model-based calculations of PAH toxic units (TU-PAH) predicted that PAH toxicities were lower in water accommodated fractions (WAFs) of irradiated oil residues (“irradiated WAFs”) than in WAFs of dark-control samples (“dark WAFs”). In contrast, biomimetic extraction (BE) measurements showed increased bioaccumulation potential of irradiated WAFs compared to dark WAFs, mainly driven by photoproducts present in irradiated oil. In line with the BE results, copepod mortality increased in response to irradiated WAFs compared to dark WAFs. Low copepod toxicities were observed for WAFs produced with photooxidized oil slicks collected during the Deepwater Horizon oil spill. The results of this study suggest that while oil photoproducts have the potential to be a significant source of copepod toxicity, the water solubility of these products might mitigate their toxicity at sea.

scholarly journals Scavenging ratio of polycyclic aromatic compounds in rain and snow at the Athabasca oil sands region

2014 ◽  
Vol 14 (13) ◽  
pp. 19395-19429
Author(s):  
L. Zhang ◽  
I. Cheng ◽  
D. Muir ◽  
J.-P. Charland
Keyword(s):  
Gas Phase ◽  
Aromatic Compounds ◽  
Oil Sands ◽  
Polycyclic Aromatic Compounds ◽  
Particulate Phase ◽  
Athabasca Oil Sands ◽  
Polycyclic Aromatic ◽  
Alkylated Pahs ◽  
Snow Samples ◽  
Air Concentrations

Abstract. Athabasca oil sands industry in northern Alberta, Canada is a possible source of polycyclic aromatic compounds (PACs). Monitored PACs, including polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes, in precipitation and in air at three near-source sites in the Fort MacKay and Fort McMurray area during May 2011 to August 2012 were analyzed to generate a database of scavenging (or washout) ratios (Wt) for PACs scavenged by both snow and rain. Median precipitation and air concentrations of parent PAHs over the May 2011 to August 2012 period ranged from 0.3–184.9 (chrysene) ng L−1 and 0.01–3.9 (naphthalene) ng m−3, respectively, which were comparable to literature values. Higher concentrations in precipitation and air were observed for alkylated PAHs and dibenzothiophenes. The median precipitation and air concentrations were 11.3–646.7 (C3-fluoranthene/pyrene) ng L−1 and 0.21–16.9 (C3-naphthalene) ng m−3, respectively, for alkylated PAHs, and 8.5–530.5 (C4-dibenzothiophene) ng L−1 and 0.13–6.6 (C2-dibenzothiophene) ng m−3 for dibenzothiophenes and their alkylated derivatives. Median Wt over the measurement period were 6100–1.1 × 106 from snow scavenging and 350–2.3 × 105 from rain scavenging depending on the PAC species. Median Wt for parent PAHs were within the range of those observed at other urban and suburban locations. But Wt for acenaphthylene in snow samples was 2–7 times higher. Some individual snow and rain samples exceeded literature values by a factor of 10. Wt for benzo(a)pyrene, dibenz(a,h)anthracene, and benzo(g,h,i)perylene in snow samples had reached 107, which is the maximum for PAH snow scavenging ratios reported in literature. From the analysis of data subsets, Wt for particulate-phase dominant PACs were 14–20 times greater than gas-phase dominant PACs in snow samples and 7–20 times greater than gas-phase dominant PACs in rain samples. Wt from snow scavenging was ∼9 times greater than rain scavenging for particulate-phase dominant PACs and 4–9.6 times greater than rain scavenging for gas-phase dominant PACs. Gas-particle fractions of each PAC, particle size distributions of particulate-phase dominant PACs, and Henry's Law constant of gas-phase dominant PACs explained, to a large extent, the different Wt values among the different PACs and precipitation types. This study verified findings from a previous study of Wang et al. (2014) which suggested that snow scavenging is more efficient than rain scavenging of particles for equivalent precipitation amount, and also provided new knowledge on the scavenging of gas-phase PACs by snow and rain.

scholarly journals Challenges in The Regulatory Use of Water Accommodated Fractions for Assessing Complex Substances

2020 ◽  
Author(s):  
James Robert Wheeler ◽  
Delina Lyon ◽  
Carolina di Paulo ◽  
Albania Grosso ◽  
Mark Crane
Keyword(s):  
Historical Development ◽  
Aquatic Toxicity ◽  
Coal Tar ◽  
The United States ◽  
Petroleum Products ◽  
Jet Fuel ◽  
Toxicity Tests ◽  
Loading Rates ◽  
Water Accommodated Fractions ◽  
Complex Substance

Abstract The use of the Water Accommodated Fraction (WAF) approach for the preparation of exposure systems of complex substances such as petroleum products has been a standard way to perform aquatic toxicity tests on these substances for over 30 years. In this Commentary we briefly describe the historical development, rationale, and guidance for the use and reporting of the WAF approach to assess complex substances. We then discuss two case studies, with coal tar pitch and kerosene/jet fuel, which illustrate challenges from regulatory authorities in Europe and the United States when using the WAF approach. We describe how the WAF approach is the only currently known method for testing the toxicity of the whole of a complex substance, even when some of its constituents remain unknown; it accounts for differences in the solubility of the constituents within a complex substance; and use of loading rates to describe any toxic effects is a unifying concept that allows direct comparison with releases of readily soluble substances in hazard assessment and chemical classification.

Extension and validation of the target lipid model for deriving predicted no-effect concentrations for soils and sediments

2014 ◽  
Vol 33 (12) ◽  
pp. 2679-2687 ◽  
Author(s):  
Aaron D. Redman ◽  
Thomas F. Parkerton ◽  
Miriam Leon Paumen ◽  
Joy A. McGrath ◽  
Klaas den Haan ◽  
...  
Keyword(s):  
Soils And Sediments ◽  
Target Lipid Model

scholarly journals The Effects of Crude Oil and Dispersant on the Larval Sponge Holobiont

mSystems ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Heidi M. Luter ◽  
Steve Whalan ◽  
Nikos Andreakis ◽  
Muhammad Abdul Wahab ◽  
Emmanuelle S. Botté ◽  
...  
Keyword(s):  
Gene Expression ◽  
Coral Reef ◽  
Crude Oil ◽  
Marine Sponges ◽  
Treatment Level ◽  
Marine Biota ◽  
Content Type ◽  
Water Accommodated Fractions ◽  
Ecological Importance ◽  
Corexit Ec9500a

ABSTRACT Accidental oil spills from shipping and during extraction can threaten marine biota, particularly coral reef species which are already under pressure from anthropogenic disturbances. Marine sponges are an important structural and functional component of coral reef ecosystems; however, despite their ecological importance, little is known about how sponges and their microbial symbionts respond to petroleum products. Here, we use a systems biology-based approach to assess the effects of water-accommodated fractions (WAF) of crude oil, chemically enhanced water-accommodated fractions of crude oil (CWAF), and dispersant (Corexit EC9500A) on the survival, metamorphosis, gene expression, and microbial symbiosis of the abundant reef sponge Rhopaloeides odorabile in larval laboratory-based assays. Larval survival was unaffected by the 100% WAF treatment (107 μg liter−1 polycyclic aromatic hydrocarbon [PAH]), whereas significant decreases in metamorphosis were observed at 13% WAF (13.9 μg liter−1 PAH). The CWAF and dispersant treatments were more toxic, with decreases in metamorphosis identified at 0.8% (0.58 μg liter−1 PAH) and 1.6% (38 mg liter−1 Corexit EC9500A), respectively. In addition to the negative impact on larval settlement, significant changes in host gene expression and disruptions to the microbiome were evident, with microbial shifts detected at the lowest treatment level (1.6% WAF; 1.7 μg liter−1 PAH), including a significant reduction in the relative abundance of a previously described thaumarchaeal symbiont. The responsiveness of the R. odorabile microbial community to the lowest level of hydrocarbon treatment highlights the utility of the sponge microbiome as a sensitive marker for exposure to crude oils and dispersants. IMPORTANCE Larvae of the sponge R. odorabile survived exposure to high concentrations of petroleum hydrocarbons; however, their ability to settle and metamorphose was adversely affected at environmentally relevant concentrations, and these effects were paralleled by marked changes in sponge gene expression and preceded by disruption of the symbiotic microbiome. Given the ecological importance of sponges, uncontrolled hydrocarbon releases from shipping accidents or production could affect sponge recruitment, which would have concomitant consequences for reef ecosystem function.

A METHOD OF EXPOSING FISH TO WATER-ACCOMMODATED FRACTIONS OF OIL

1997 ◽  
Vol 1997 (1) ◽  
pp. 941-942 ◽  
Author(s):  
Sandra Blenkinsopp ◽  
Gary Sergy ◽  
Ken Doe ◽  
Gary Wohlgeschaffen ◽  
Ken Li ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Aeration Rate ◽  
Test Solution ◽  
Oxygen Levels ◽  
Water Accommodated Fractions

ABSTRACT The purpose of this study was to determine how to expose rainbow trout to water-accommodated fractions (WAF) from oil, for 96-hour acute lethality testing. Oxygen levels and WAF loss were monitored for a variety of exposure, aeration and fish loading density combinations. Aeration is needed, but the normal aeration rate (NAR) of 6.5 ± 1 mL air/L test solution/minute can be reduced to 1/10 NAR. Also, open and loosely sealed bags with an NAR exhibited a 90% WAF loss in the first 24 hours, compared with a 30% WAF loss by loosely sealed bags with 1/10 NAR. The latter method is therefore preferred for the static exposure of rainbow trout to WAF.

scholarly journals Scavenging ratios of polycyclic aromatic compounds in rain and snow in the Athabasca oil sands region

2015 ◽  
Vol 15 (3) ◽  
pp. 1421-1434 ◽  
Author(s):  
L. Zhang ◽  
I. Cheng ◽  
D. Muir ◽  
J.-P. Charland
Keyword(s):  
Gas Phase ◽  
Aromatic Compounds ◽  
Oil Sands ◽  
Polycyclic Aromatic Compounds ◽  
Particulate Phase ◽  
Athabasca Oil Sands ◽  
Polycyclic Aromatic ◽  
Alkylated Pahs ◽  
Scavenging Ratios ◽  
Snow Samples

Abstract. The Athabasca oil sands industry in northern Alberta, Canada, is a possible source of polycyclic aromatic compounds (PACs). Monitored PACs, including polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes (DBTs), in precipitation and in air at three near-source sites in the Fort MacKay and Fort McMurray area during January 2011 to May 2012, were used to generate a database of scavenging ratios (Wt) for PACs scavenged by both snow and rain. Higher concentrations in precipitation and air were observed for alkylated PAHs and DBTs compared to the other PACs. The sums of the median precipitation concentrations over the period of data analyzed were 0.48 μ g L−1 for the 18 PAHs, 3.38 μ g L−1 for the 20 alkylated PAHs, and 0.94 μ g L−1 for the 5 DBTs. The sums of the median air concentrations for parent PAHs, alkylated PAHs, and DBTs were 8.37, 67.26, and 11.83 ng m−3, respectively. Median Wt over the measurement period were 6100 – 1.1 × 106 from snow scavenging and 350 – 2.3 × 105 from rain scavenging depending on the PAC species. Median Wt for parent PAHs were within the range of those observed at other urban and suburban locations, but Wt for acenaphthylene in snow samples were 2–7 times higher compared to other urban and suburban locations. Wt for some individual snow and rain samples exceeded literature values by a factor of 10. Wt for benzo(a)pyrene, dibenz(a,h)anthracene, and benzo(g,h,i)perylene in snow samples had reached 107, which is the maximum for PAH snow scavenging ratios reported in the literature. From the analysis of data subsets, Wt for particulate-phase dominant PACs were 14–20 times greater than gas-phase dominant PACs in snow samples and 7–20 times greater than gas-phase dominant PACs in rain samples. Wt from snow scavenging were ~ 9 times greater than from rain scavenging for particulate-phase dominant PACs and 4–9.6 times greater than from rain scavenging for gas-phase dominant PACs. Gas-particle fractions of each PAC, particle size distributions of particulate-phase dominant PACs, and the Henry's law constant of gas-phase dominant PACs explained, to a large extent, the different Wt values among the different PACs and precipitation types. The trend in Wt with increasing alkyl substitutions may be attributed to their physico-chemical properties, such as octanol–air and particle partition coefficients and subcooled vapor pressure, which increases gas-particle partitioning and, subsequently, the particulate mass fraction. This study verified findings from a previous study of Wang et al. (2014) that suggested that snow scavenging is more efficient than rain scavenging of particles for equivalent precipitation amounts, and also provided new knowledge of the scavenging of gas-phase PACs and alkylated PACs by snow and rain.

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