In vitro cytotoxicity assessment of a hydraulic fracturing fluidMadeleine E. Payne A C , Heather F. Chapman A , Janet Cumming B and Frederic D. L. Leusch A
A Smart Water Research Centre, Griffith University, Gold Coast Campus, Southport, Qld 4222, Australia.
B Queensland Health, 15 Butterfield Street, Herston, Qld 4006, Australia.
C Corresponding author. Present address: Queensland Institute of Medical Research, Locked Bag 2000, Royal Brisbane Hospital, Qld 4029, Australia. Email: email@example.com
Environmental Chemistry 12(3) 286-292 https://doi.org/10.1071/EN14010
Submitted: 13 January 2014 Accepted: 15 April 2014 Published: 8 August 2014
Abstract. Hydraulic fracturing fluids are chemical mixtures used to enhance oil and gas extraction. There are concerns that fracturing fluids are hazardous and that their release into the environment – by direct injection to coal and shale formations or as residue in produced water – may have effects on ecosystems, water quality and public health. This study aimed to characterise the acute cytotoxicity of a hydraulic fracturing fluid using a human gastrointestinal cell line and, using this data, contribute to the understanding of potential human health risks posed by coal seam gas (CSG) extraction in Queensland, Australia. Previous published research on the health effects of hydraulic fracturing fluids has been limited to desktop studies of individual chemicals. As such, this study is one of the first attempts to characterise the toxicity of a hydraulic fracturing mixture using laboratory methods. The fracturing fluid was determined to be cytotoxic, with half maximal inhibitory concentrations (IC50) values across mixture variations ranging between 25 and 51 mM. When used by industry, these fracturing fluids would be at concentrations of over 200 mM before injection into the coal seam. A 5-fold dilution would be sufficient to reduce the toxicity of the fluids to below the detection limit of the assay. It is unlikely that human exposure would occur at these high (‘before use’) concentrations and likely that the fluids would be diluted during use. Thus, it can be inferred that the level of acute risk to human health associated with the use of these fracturing fluids is low. However, a thorough exposure assessment and additional chronic and targeted toxicity assessments are required to conclusively determine human health risks.
Additional keywords: Caco-2 cell line, chemical additives, coal seam gas, mixture toxicity, neutral red uptake.
References G. S. Penny, M. W. Conway, Coordinated laboratory studies in support of hydraulic fracturing of coalbed methane, in Proceedings of the 66th Annual Technical Conference and Exhibition of the Society of Petroleum Engineers, 6–9 October 1991, Dallas, TX, 1991 (Society of Petroleum Engineers). Abstract available at https://www.onepetro.org/conference-paper/SPE-22911-MS [Verified 25 June 2014].
 Evaluation of impacts to underground sources of drinking water by hydraulic fracturing of coalbed methane reservoirs, EPA 816-R-04-003 2004 (US Environmental Protection Agency: Washington, DC).
 Coal seam hydraulic fracturing fluid environmental risk assessment: response to the coordinator-general requirements for coal seam gas operations in the Surat and Bowen Basins Queensland, Contract 107626105-001-R-Rev5 2010 (Golder Associates)
 Y. Knight, C. Cheung, S. Denner, Hydraulic Fracturing Environmental Assessment. Environmental consultant technical report prepared for APLNG, Document Number 42626654 2010 (URS Consulting: Brisbane, Qld).
 D. J. Rozell, S. J. Reaven, Water pollution risk associated with natural gas extraction from the Marcellus Shale Risk Anal. 2012, 32, 1382.
| Water pollution risk associated with natural gas extraction from the Marcellus ShaleCrossRef | 22211399PubMed |
 J. Fox, Gasland. (2010) 2010. Available at http://www.filmsforaction.org/watch/gasland_2010/ [Verified 25 June 2014].
 T. Colborn, C. Kwiatkowski, K. Schultz, M. Bachran, Natural gas operations from a public health perspective Hum. Ecol. Risk Assess. 2011, 17, 1039.
| Natural gas operations from a public health perspectiveCrossRef | 1:CAS:528:DC%2BC3MXht1WmtL7F&md5=8141631e491cbad1fd0ae2c6b8e283b7CAS |
 M. Bamberger, R. E. Oswald, Impacts of gas drilling on human and animal health New Solut. 2012, 22, 51.
| Impacts of gas drilling on human and animal healthCrossRef | 22446060PubMed |
 A. Aminto, M. S. Olson, Four-compartment partition model of hazardous components in hydraulic fracturing fluid additives J. Nat. Gas Sci. Eng. 2012, 7, 16.
| Four-compartment partition model of hazardous components in hydraulic fracturing fluid additivesCrossRef | 1:CAS:528:DC%2BC38XnvFOrtrg%3D&md5=0fe2f50049728218636ba455996ced7aCAS |
 Revised draft SGEIS on the oil, gas and solution mining regulatory program (September 2011) 2011 (New York Department of Environmental Conservation: Albany, NY). Available at http://www.dec.ny.gov/energy/75370.html [Verified 25 June 2014].
 D. E. Putzig, Process to prepare borozirconate solution and use as cross-linker in hydraulic fracturing fluids, US Patent number US 20090149355 A1 2009. Available at http://www.google.com/patents/US20090149355 [Verified 25 June 2014].
 J. W. Dobson, S. L. Hayden, K. A. Pierce, Methods, systems, and compositions for the controlled crosslinking of well servicing fluids, US Patent number WO2009111324 A1 2010. Available at http://www.google.com/patents/WO2009111324A1?cl=en [Verified 25 June 2014].
 P. C. Harris, M. A. McCabe, L. R. Norman, R. J. Powell, C. E. Shuchart, B. F. Slabaugh, J. M. Terracina, J. G. Yaritz, Borate cross-linked well treating fluids and methods, US Patent number US5827804 A 1998. Available at http://www.google.sh/patents/US5827804 [Verified 25 June 2014].
 K. Nimerick, Borate crosslinked fracturing fluid and method, US Patent number US5681796 A 1997. Available at http://www.google.com.au/patents/US5681796 [Verified 25 June 2014].
 J. L. Gidley, S. A. Holditch, D. E. Nierode, R. W. Veatch (Eds), Recent Advances in Hydraulic Fracturing 1989 (Henry L. Doherty Memorial Fund of AIME, Society of Petroleum Engineers: Richardson, TX).
 M. J. Economides, K. G. Nolte, Reservoir Stimulation, 2nd edn 1989 (Sclumberger Educational Services: Houston, TX).
 P. C. Harris, A. Sabhapondit, Chemistry applied to fracture stimulation of petroleum wells. In Proceedings of the 2009 Society of Petroleum Engineers Middle East Oil and Gas Show and Conference, 15–18 March, Bahrain, 2009 (Society of Petroleum Engineers) Abstract available at https://www.onepetro.org/conference-paper/SPE-120029-MS [Verified 25 June 2014].
 In Vitro Cytotoxicity Test Methods for Estimating Starting Doses for Acute Oral Systemic Toxicity Testing 2006 (Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM): Research Triangle Park, NC).
 B. Escher, F. Leusch, H. Chapman, A. Poulsen, Bioanalytical Tools in Water Quality Assessment 2012 (IWA Publishing: London, UK).
 A. Kortenkamp, M. Faust, M. Scholze, T. Backhaus, Low-level exposure to multiple chemicals: reason for human health concerns? Environ. Health Perspect. 2007, 115, 106.
| Low-level exposure to multiple chemicals: reason for human health concerns?CrossRef | 18174958PubMed |
 Chemicals Used in Fraccing 2012 (Queensland Government, Department of Environment and Heritage Protection). Available at http://www.ehp.qld.gov.au/management/non-mining/fraccing-chemicals.html [Verified 25 July 2014].
 Hydraulic Fracturing Chemicals used by QGC 2008 (QGC). Available at http://www.qgc.com.au/01_cms/details.asp?ID=532 [Verified 16 May 2012].
 What Fraccing Fluids are Used by Arrow? 2011 (Arrow Energy). Available at http://www.arrowenergy.com.au/page/Community/FAQs/-item-87358 [Verified 16 May 2012].
 Hydraulic Fracturing: Stimulating the Coal Seam to Generate Gas Flow 2011 (Santos). Available at http://www.glng.com.au/library/Hydraulic_Fracturing_-_Fact_Sheet.pdf [Verified 16 May 2012].
 A. E. McGrath, (Ed.) Fate and transport of select compounds of interest in fracing fluids, in US EPA Proceedings of the Technical Workshops for the Hydraulic Fracturing Study, Fate and Transport, EPA 600/R-11/047, 28–29 March 2011, Arlington, VA, 2011 (Office of Research and Development, US Environmental Protection Agency: Washington, DC). Available at http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/upload/fateandtransportofselectcompoundsofinterestinfracingfluids.pdf [Verified 30 July 2014].
 E. Borenfreund, J. A. Puerner, Cytotoxicity of metals, metal-metal and metal-chelator combinations assayed in vitro Toxicology 1986, 39, 121.
| Cytotoxicity of metals, metal-metal and metal-chelator combinations assayed in vitroCrossRef | 1:CAS:528:DyaL28Xit1Sgurg%3D&md5=7c20639e56d3c2ebdde4671714639930CAS | 3705079PubMed |
 R. Konsoula, F. A. Barile, Correlation of in vitro cytotoxicity with paracellular permeability in Caco-2 cells Toxicol. In Vitro 2005, 19, 675.
| Correlation of in vitro cytotoxicity with paracellular permeability in Caco-2 cellsCrossRef | 1:CAS:528:DC%2BD2MXkt1OitL8%3D&md5=ae1cbe67be2214b6d8960b6a130b8420CAS | 15896555PubMed |
 Report of the International Workshop on In Vitro Methods for Assessing Acute Systemic Toxicity. NIH Publication 01–4499 2001 (Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM): Research Triangle Park, NC, USA).
 ChemIDplus Advanced 2013 (United States National Library of Medicine, National Institutes of Health, Department of Health & Human Services: Bethseda, MD).
 TOXNET: Toxicology Data Network 2013 (United States National Library of Medicine, National Institutes of Health, Department of Health & Human Services: Bethseda, MD).
 Ethylene Glycol: Human Health Aspects, Concise International Chemical Assessment Document 45 2002 (World Health Organization). Available at http://www.inchem.org/documents/cicads/cicads/cicad45.htm [Verified 19 October 2012].
 A. Kortenkamp, T. Backhaus, M. Faust, State of the Art Report on Mixture Toxicity, Contract 070307/2007485103/ETU/D.1 2009 (School of Pharmacy, University of London: London) Available at http://ec.europa.eu/environment/chemicals/effects/pdf/report_mixture_toxicity.pdf [Verified 25 July 2014].
 Guidance Document on using In Vitro Data to Estimate In Vivo Starting Doses for Acute Toxicity 2001 (Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM): Research Triangle Park, NC).