The health implications of fracking: Article in the Lancet

The Lancet, Volume 383, Issue 9919, Pages 757 – 758, 1 March 2014

doi:10.1016/S0140-6736(13)62700-2Cite or Link Using DOI

Copyright © 2014 Elsevier Ltd All rights reserved.

The health implications of fracking

Sari Kovats a, Michael Depledge b, Andy Haines a, Lora E Fleming c, Paul Wilkinson a, Seth B Shonkoff d e, Noah Scovronick a

What is known about the health effects of gas extraction by induced hydraulic fracturing of gas-bearing rock—ie, fracking? A workshop held on Nov 15, 2013, at the London School of Hygiene and Tropical Medicine and attended by scientists, public health professionals, and decision makers addressed this question.

Fracking is at a very early stage in the UK, with only one shale gas well tested so far. This situation provides an important opportunity to gather information and to conduct studies of health and environmental effects before any large-scale development. Scientific study of the health effects of fracking is in its infancy,1, 2 but findings suggest that this form of extraction might increase health risks compared with conventional oil and gas wells because of the larger surface footprints of fracking sites; their close proximity to locations where people live, work, and play; and the need to transport and store large volumes of materials.3—6 In the USA, where more than 52 000 shale gas wells have been drilled, data suggest that risks of environmental contamination occur at all stages in the development of shale gas extraction. Failure of the structural integrity of the well cement and casing,7 surface spills and leakage from above-ground storage, emissions from gas-processing equipment, and the large numbers of heavy transport vehicles involved are the most important factors that contribute to environmental contamination and exposures in the USA.2

Environmental exposures include outdoor air pollutants (ie, volatile organic compounds, tropospheric ozone, and diesel particulate matter)2 and pollutants (ie, benzene, hydrocarbons, endocrine-disrupting chemicals, and heavy metals) in both ground8 and surface9, 10 water. Known occupational hazards include airborne silica exposure at the well pad.11 Toxicological data for the chemicals injected into wells (so-called frac fluid) indicate that many of them have known adverse effects on health, with no toxicological data available for some.2 Assessment of potential risks has been difficult in the USA because drilling operators are not required to disclose which chemicals are used, but the UK Government has accepted the recommendation from the Royal Society and Royal Academy of Engineering Working Group on shale gas extraction1 for full disclosure.12 Exposure and epidemiological studies—of which there are currently very few—are needed along the entire supply chain of shale gas to characterise and quantify associated health issues. The socioeconomic implications of shale gas development on local communities before, during, and after extraction, and how risks should be communicated, are also important research priorities.

In addition to local health and environment threats, an important consideration is the contribution of shale gas extraction to greenhouse-gas emissions and, thus, to climate change. Although there is conflicting evidence about the comparative contribution of lifecycle greenhouse gases of shale gas relative to coal, evidence from the USA indicates that instead of replacing coal, shale gas has rapidly become an additional source of fossil fuel, leading to an increase in cumulative global greenhouse-gas emissions.13 The degree to which shale gas extraction is developed should be based on comparisons with other energy options, including renewable energy sources, and greater investment in energy efficiency measures, taking full account of environmental, economic, and health implications.

Health impact assessments on fracking can provide evidence-based input at several levels of decision making in the UK’s regulatory framework, including in the formulation of national policy and in local planning processes. Information generated from health impact assessments can allow modifications to a project licence to reduce health effects. However, key issues for health impact assessments are which comparators and timeframes to use, and which stages in the lifecycle of oil and gas development to include. For example, it might be important for health impact assessments to include the long-term implications of waste disposal, fugitive methane emissions, and other legacies with implications for human health, as opposed to analyses of only environmental and public health risks during active development. Given the diversity of stakeholders, the technical challenges, and the different stages of development of the fracking industry between regions and countries, there is a need to share data and lessons that have been learned.

Full-size image (85K) Dale G Young/Associated Press

Climate policies and declining fuel reserves will drive substantial changes in energy policy in the coming decades. Shale gas development shares many science policy questions with other proposed energy alternatives and, therefore, provides a good case study into the different factors at play and associated challenges. Locally, nationally, and globally, costs and benefits of new energy options need to be assessed quickly. Public health professionals have a role in informing decisions about fracking in the UK and in monitoring to ensure that, if it does proceed, “operational best practices are implemented and enforced through regulation”.1

We declare that we have no competing interests. The workshop was sponsored by the Irish Environmental Protection Agency through an award to MD and was organised by SK, MD, AH, LEF, PW, and SBS; LEF and MD received financial support from the European Region Development Fund and European Social Fund.


1 The Royal Society, Royal Academy of Engineering. Shale gas extraction in the UK: a review of hydraulic fracturing, June 2012. London: The Royal Society and Royal Academy of Engineering, 2012.

2 Public Health England. Review of the potential public health impacts of exposures to chemical and radioactive pollutants as a result of the shale gas extraction. London: Public Health England, 2013.

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9 Fontenot BE, Hunt LR, Hildenbrand ZL, et al. An evaluation of water quality in private drinking water wells near natural gas extraction sites in the Barnett Shale Formation. Environ Sci Technol 2013; 47: 10032-10040. CrossRef | PubMed

10 Kassotis CD, Tillitt DE, Davis JW, Hormann AM, Nagel SC. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region. Endocrinology 201310.1210/en.2013-1697. published online Jan 1. PubMed

11 Esswein EJ, Breitenstein M, Snawder J, Kiefer M, Sieber WK. Occupational exposures to respirable crystalline silica during hydraulic fracturing. J Occup Environ Hyg 2013; 10: 347-356. CrossRef | PubMed

12 HM Government. Government response to Royal Academy of Engineering and Royal Society report on “Shale gas extraction in the UK: a review of hydraulic fracturing”. (accessed Oct 15, 2013)

13 Broderick J, Anderson K. Has US shale gas reduced CO2 emissions? Technical paper. Tyndall Manchester, University of Manchester. (accessed Oct 15, 2013).

a Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK

b European Centre for the Environment and Human Health, University of Exeter Medical School, Exeter, UK

c European Centre for the Environment and Human Health, University of Exeter Medical School, Truro, UK

d Physicians, Scientists, and Engineers for Healthy Energy, Oakland, CA, USA

e University of California, Berkeley, CA, USA

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Posted on: March 24, 2014