TitleMutagenicity assessment downstream of oil and gas produced water discharges intended for agricultural beneficial reuse.
Publication TypeJournal Article
Year of Publication2020
AuthorsMcLaughlin, MC, Blotevogel, J, Watson, RA, Schell, B, Blewett, TA, Folkerts, EJ, Goss, GG, Truong, L, Tanguay, RL, Argueso, JLucas, Borch, T
JournalSci Total Environ
Volume715
Pagination136944
Date Published2020 May 01
ISSN1879-1026
KeywordsAnimals, Daphnia, DNA Copy Number Variations, Gases, Mutagens, Oils, United States, Water, Water Pollutants, Chemical
Abstract

Produced water is the largest waste stream associated with oil and gas operations. This complex fluid contains petroleum hydrocarbons, heavy metals, salts, naturally occurring radioactive materials and any remaining chemical additives. In the United States, west of the 98th meridian, the federal National Pollutant Discharge Elimination System (NPDES) exemption allows release of produced water for agricultural beneficial reuse. The goal of this study was to quantify mutagenicity of a produced water NPDES release and discharge stream. We used four mutation assays in budding yeast cells that provide rate estimates for copy number variation (CNV) duplications and deletions, as well as forward and reversion point mutations. Higher mutation rates were observed at the discharge and decreased with distance downstream, which correlated with the concentrations of known carcinogens detected in the stream (e.g., benzene, radium), described in a companion study. Mutation rate increases were most prominent for CNV duplications and were higher than mutations observed in mixtures of known toxic compounds. Additionally, the samples were evaluated for acute toxicity in Daphnia magna and developmental toxicity in zebrafish. Acute toxicity was minimal, and no developmental toxicity was observed. This study illustrates that chemical analysis alone (McLaughlin et al., 2020) is insufficient for characterizing the risk of produced water NPDES releases and that a thorough evaluation of chronic toxicity is necessary to fully assess produced water for beneficial reuse.

DOI10.1016/j.scitotenv.2020.136944
Alternate JournalSci Total Environ
PubMed ID32014773
PubMed Central IDPMC7243347
Grant ListR35 GM119788 / GM / NIGMS NIH HHS / United States