Fracking poses little risk to public health, but evidence is limited

Fracking to extract shale gas is unlikely to have a detrimental effect on the health of people living nearby, provided that operations are properly run and regulated, a report from Public Health England has concluded.

However, the body has admitted that little robust research has looked specifically at the health implications of fracking and that most of the existing data come from the United States, which has a different geology and may use different chemicals and procedures to the ones that could be used in the United Kingdom.

Fracking involves the pumping of water and chemicals into dense shale formations to push out gas and oil. The review by Public Health England’s centre for radiation, chemical, and environmental hazards, whose findings were published in a draft report on 31 October, focuses on the potential effects on health of the chemicals used and any radioactive material released.1

One of the risks the review looked at is the potential for contamination of groundwater. The report emphasises that the underground fracking process itself is unlikely to cause groundwater contamination, because it takes place far below the groundwater level. Most evidence from overseas indicates that where contamination has occurred it has been related to surface contamination or leakage through the vertical borehole into the groundwater.

Robie Kamanyire, head of the environmental hazards and emergencies department at Public Health England and one of the authors of the report, told the BMJ that in incidents where groundwater had been contaminated there had been “no clear evidence of adverse health effects. There have been some complaints of non-specific symptoms, such as headaches [and] skin rashes, but those can’t be clearly attributed to shale gas operations.”

He added that the risks of groundwater contamination were not unique to shale gas extraction, being present in all types of oil and gas extraction activity. “The important thing will be proper operation and regulation, and in this country we do have very strong regulatory procedures,” he said.

In its report Public Health England emphasised the need to assess each potential fracking site individually and recommended that it continued to work with regulators to ensure that all aspects of shale gas extraction were properly risk assessed, including noise, odours, and visual impact. It added that if shale gas extraction were allowed, environmental monitoring would be needed before, during, and after extraction to enable assessment of the effects on the environment and public health, such as in terms of any change in levels of environmental radon or methane in groundwater. Furthermore, it said that the chemicals used in fracking fluid should be publicly disclosed and risk assessed before use.

Currently no company is extracting shale gas commercially in the UK, but the oil extraction company Cuadrilla has been granted permission for test drilling and is operating at three sites. Cuadrilla was forced to shut one site in Lancashire after an earth tremor caused by drilling caused the well to deform. Although the integrity of the well was not compromised, deformation of well casings can allow gas or fracking fluids to escape. Cuadrilla did not report the incident to the Department of the Environment for six months, prompting a warning from ministers over its “performance as a licensee.”2

When asked whether this incident raised concern about the robustness of the regulatory processes, John Newton, chief knowledge officer at Public Health England, said, “That’s not really a matter for Public Health England. We have pointed out that the health risks are dependent on these processes being well run and well regulated.”

He added, “The purpose of the report is to provide a framework or background information for regulators to do their job, but it is not our job to do the regulation.”

The energy minister, Michael Fallon, said, “The UK has the most robust regulatory regime in the world for shale gas, and companies will only be granted permission to frack for shale if their operations are safe.

“Public safety and health are paramount, and the government will continue to work with industry to ensure stringent safety guidelines are upheld as they explore the great potential for shale.”

However, the Greenpeace energy campaigner Leila Deen warned that the government had cut the budget of the environmental regulator and was “effectively allowing companies to mark their own homework when it comes to monitoring.”

Commenting on Public Health England’s report, Quentin Fisher, professor of petroleum geoengineering at Leeds University, said, “Leakage along boreholes is far less likely in the UK compared with the US because we have never had a large onshore petroleum development programme, so pre-existing boreholes close to the shale gas resources are not a significant issue.”

However, Richard Davies, professor and director of the energy institute at Durham University, said, “Of the 2152 wells drilled onshore in the UK since 1902, approximately 50% are buried and therefore not easily monitored, and 1138 were drilled by companies that no longer exist. If the rocks are suitable and the UK presses ahead, then well integrity is an area that will need a great deal more focus.”