Early Life Effects of Produced Water on Menidia Beryllina Juveniles.

KROLL, KEVIN ; DENSLOW, NANCY; LÓPEZ GONZÁLEZ EVELYN C.; DE MARÍA MULLET, MAITE

Sacramento

Congreso; Society of Environmental Toxicology and Chemistry (SETAC) 39th annual meeting; 2018

Society of Environmental Toxicology and Chemistry (SETAC)

The composition of produced water from extraction of gas and oil from shale is complex, containing the chemicals that were added to make it work effectively plus hydrocarbons and salts that vary depending on the geochemistry of the site. Dissolved solids can range from 100 mg/L to 400,000 mg/L. We tested produced water from two wells in Texas that were from the same geological formation but differed in length of time of operation. One was in operation for 6 months and the other for 3 years. Raw waters were characterized for various chemical parameters and fractionated by solid phase extraction following usual EPA proceduresfor toxicity identification evaluations. Ten-day old Menidia beryllina juveniles were used in 72 h acute toxicity tests of both raw samples at 10%, 3%, 1%, and 0.3 % and SPE fractions at 100%, 10%, and 3% initial concentrations, respectively. Exposures were conducted using 8 juveniles/ dish and 6 replicates per treatment. Fifty percent of the exposure solution was changed daily. The MEOH extracts of the fractionated water samples were the most toxic in terms of fish survival. Fish exposed to sublethal concentrations of the raw waters were evaluated for gene expression alterations using RNAseq. Cyp1A, StAR-related lipid transfer protein and long chain fatty acid transporters were among the genes most highly up regulated by the exposures while DNA repair protein RAD 51 was the most down-regulated transcript. Gene set enrichment analysis suggests pathways related to cancer, cardiomyopathy, ROS generation and inflam- mation may be sublethal targets of the exposures.