It's been a week of activity for the Balcombe anti-fracking activists brandishing their banners "For a frack-free future."
The campaigners have highlighted numerous concerns over the controversial process of extracting gas, including water table contamination, potential emissions of climate-changing methane and worries over community disruption from many lorries that will have to come to areas hosting fracking platforms with toxic liquids used to flush out shale gas.
Earlier this month in the Daily Telegraph David Cameron tried to counter these environmental concerns by referring to a "stringent regulatory system."
Cameron's coalition partners also give cautious support for shale gas in a motion to be debated at the Lib Dem conference next month, saying limited shale gas extraction should be allowed providing that "regulations controlling pollution and protecting local environmental quality are strictly enforced."
But neither of the Con-Dem coalition partners, nor indeed the protesters in Balcombe, make any mention of potential radioactive risks.
However Cameron's own Health Minister Anna Soubry revealed earlier this year that Public Health England (formerly the Health Protection Agency) is preparing a report identifying potential public health concerns, including radon emissions, that might be associated with fracking.
The report had been due out for public consultation in the summer. But PHE has told me that it now does not expect its report to see light before the end of the year, which is hugely disappointing considering its prospective importance to public debate.
PHE is evaluating the potential risks of radon gas being pumped into people's homes as part of the shale gas stream.
Unless the gas is stored for several days to allow the radon's radioactivity to naturally reduce, this is potentially very dangerous.
A report produced by the Health Protection Agency in 2009, Radon and Public Health, states: "Radon is a naturally occurring colourless and odourless radioactive gas that can seep out of the ground and build up in houses, buildings and indoor workplaces.
"Epidemiological studies have established that exposure to radon is a cause of lung cancer.
"Exposure to radon is now recognised as the second-largest cause of lung cancer in the UK after smoking and analysis for the Health Protection Agency indicates that about 1,100 UK deaths from lung cancer each year are caused by exposure to radon (most caused jointly by radon and smoking)."
Initially radon released from its virtually sealed underground locations will be in suspension, but it then accretes onto dust particles, pipework etc, and some of it may remain suspended in the gas and come out in our cookers.
The concern about how much radon is likely to be piped into people's kitchens was spurred by a report last year by Dr Marvin Resnikoff of US researchers at Radioactive Waste Management Associates.
Resnikoff estimated radon levels at the wellhead as being up to 70 times the average and reports that the Marcellus shale has as much as 30 times the radiation that is found in normal background.
Professor James W Ring of Hamilton College in New York State says: "The radon and natural gas coming from the shale mix together and travel together as the gas is piped to customers.
"This is a serious health hazard, as radon, being a gas, is breathed into the lungs and lodges there to decay, doing damage to the lung's tissue and eventually leading to lung cancer."
Radon's half life means that fracked gas would need to be stored for at least a month before being distributed to people's homes to allow for this radioactive decay of radon.
The Radon Council, formed in 1990, is an independent non-profit-making self-regulatory body for industry.
Its formation was welcomed in the interim report of the parliamentary select committee on indoor pollution, which called upon industry to provide a solution to the radon problem.
The first objectives were to identify the "cowboy" operators and dubious training courses then in practice.
Later there followed a first edition of a training manual and an agreed code of practice for the industry.
It does not seem that ministers have read any of the Radon Council's literature, so gung-ho are they for fracking.
At the end of July the Department for Communities and Local Government published its revision of building regulation policy on radon.
"Alongside a health and awareness programme and testing and remediation of existing buildings, current government policy includes targeted intervention through the building regulations which requires radon protection in new buildings in areas of elevated radon risk... We intend that the building regulations and supporting statutory guidance is clear on current radon risks and ensures buildings are fitted with proportionate measures to prevent the ingress of radon and thus reduce radon-related lung cancers. "
It also states boldly: "The chosen policy will maintain a targeted regulatory intervention (aligned to the most up-to-date radon maps), to ensure that all buildings in higher-risk areas incorporate appropriate radon measures."
In light of this clear precautionary approach, it is odd that all ministers seem to be cheerleading for expanded fracking, despite its possible radon risk.
In addition to the US research, the internationally respected Norwegian environmental consultancy Det Norske Veritas has identified radioactive waste contamination as a problem with fracking, arising from contaminated rock cuttings and cores which have the potential to harm health.
In Sweden, the handling of radioactive shales requires a permit from the Swedish Radiation Safety Authority when the uranium content exceeds 80 parts per million.
Non-compliance with the permit can lead to it being revoked and, if done intentionally, the responsible person can be fined or even imprisoned.
Green MP Caroline Lucas, who was arrested at Balcombe on Monday, initiated a debate on fracking on July 18 and drew attention to the radon risk and the outstanding PHE report.
She asked the Minister for Business Michael Fallon pointedly whether he would "explain the delay in publishing this research report when the public debate over fracking is moving ahead apace?"
Fallon replied to several of Lucas's questions on environmental hazards of fracking, but ignored the one on radon risks. I wonder why?
Once released the PHE report will be available at www.gov.uk/government/organisations/public-health-england