Thursday December 11, 2014 0 comments
FORT COLLINS - A comprehensive, nearly year-long review by Colorado State University of biocides used in hydraulic fracturing (fracking) of oil-and-gas wells indicates many have chronic toxicity effects on humans.
The report, "Biocides in Hydraulic Fracturing Fluids: A Critical Review of their Usage, Mobility, Degradation and Toxicity" recently published in the journal Environmental Science and Technology, also notes that alternatives to the toxic biocides are available but are rarely used due to higher costs or possible toxic byproduct formation.
CSU said a CSU-led research team analyzed more than 200 research papers, studies and other literature to critically evaluate the current knowledge on how the chemicals may enter the environment, whether they are likely to degrade or persist and if their degradation products may pose a risk to human health and the environment.
"We were trying to figure out if there is sufficient information available for an accurate environmental impact assessment of this important class of chemical compounds and identify where the major knowledge gaps are," said Jens Blotevogel, lead author of the paper.
The report notes that, of the 16 major biocides used in fracking, nine have been reported to have chronic toxic effects (such as developmental, reproductive, mutagenic, carcinogenic or neurological effects).
Of the seven not showing any evidence of chronic toxicity, three may transform into intermediate products with toxic potential, the report says.
Biocides are added to fracking fluids to kill bacteria that can corrode well casings, limit the efficacy of oil and gas extraction and produce highly toxic hydrogen sulfide gas.
The CSU review identifies various areas in which more research is "urgently needed" and looks at the pros and cons of potential biocide alternatives.