Photochemical mobilization of dissolved hydrocarbon oxidation products from petroleum contaminated soil into a shallow aquifer activate human nuclear receptors

• Published in: Journal of hazardous materials 2023-10, Vol.459, p.132312-132312, Article 132312
• Main Authors: Zito, Phoebe, Bekins, Barbara A., Martinović-Weigelt, Dalma, Harsha, Maxwell L., Humpal, Katherine E., Trost, Jared, Cozzarelli, Isabelle, Mazzoleni, Lynn R., Schum, Simeon K., Podgorski, David C.
• Format: Article
• Language: English
• Subjects: Attagene; Biodegradation; HNR; NVDOC; Oil spill; Toxicity
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.132312

Elevated non-volatile dissolved organic carbon (NVDOC) concentrations in groundwater (GW) monitoring wells under oil-contaminated hydrophobic soils originating from a pipeline rupture at the National Crude Oil Spill & Natural Attenuation Research Site near Bemidji, MN are documented. We hypothesized the elevated NVDOC is comprised of water-soluble photooxidation products transported from the surface to the aquifer. We use field and laboratory samples in combination with complementary analytical methods to test this hypothesis and determine the biological response to these products. Observations from optical spectroscopy and ultrahigh-resolution mass spectrometry reveal a significant correlation between the chemical composition of NVDOC leached from photochemically weathered soils and GW monitoring wells with high NVDOC concentrations measured in the aquifer beneath the contaminated soil. Conversely, the chemical composition from the uncontaminated soil photoleachate matches the NVDOC observed in the uncontaminated wells. Contaminated GW and photodissolution leachates from contaminated soil activated biological targets indicative of xenobiotic metabolism and exhibited potential for adverse effects. Newly formed hydrocarbon oxidation products (HOPs) from fresh oil could be distinguished from those downgradient. This study illustrates another pathway for dissolved HOPs to infiltrate GW and potentially affect human health and the environment. [Display omitted] •NVDOC from the contaminated soil was significantly higher than uncontaminated soil.•Uncontaminated soil photoleachate showed negligible change in NVDOC.•Increase in aromaticity and O molecular features in contaminated photoleachate.•HOPs from biodegraded and photodegraded oil have different chemical compositions.•Cell-based assays reveal activation of HNR receptors from HOPS-contaminated samples.