Although traces of perfluorooctane sulphonate – or PFOS – found in boreholes around the Airport are within safe limits for drinking water, a nearby stream tested positive at a level of 1.2400μg/l – above the 1.0μg/l level that is considered safe to consume.
Meanwhile, inquiries are under way to find out if foam containing PFOS could have been used to fight fires elsewhere in the Island.
Concerns were first raised in the 1990s when it was discovered that run-off from the Airport fire service training ground had polluted boreholes in the area.
And earlier this year traces of PFOS, attributed to foam used to fight a blaze after a plane crash in 1980, were found in boreholes in a nearby area of St Peter.
The boreholes affected by the 1990s pollution are now to be re-tested, and the head of Environmental Health, Stewart Petrie, has said the authorities cannot rule out more widespread issues if foam containing PFOS had been used on other fires around the Island.
Around 8% of properties are currently on borehole water, with around 3,000 properties using them for drinking water.
Guidance for borehole users Islandwide is now being reissued and updated, and includes advice that pregnant women, nursing mothers and children under five should not drink borehole water unless it is known exactly what it contains.
And borehole owners are being urged to ensure they are registered with the Environment Department to make sure they receive advice and information, and can be contacted if necessary.
Locations around the Island will now be tested, with positive results used to inform further focused sampling in that area. The sampling includes 40 boreholes regularly tested by the Environment Department and for which historic data has been recorded to enable any patterns to be traced.
‘We are about to start another sampling programme of 250 locations across the Island,’ said Mr Petrie, who was one of the officials who spoke at a public meeting for St Peter residents concerned about PFOS contamination last week.
‘We have got one chance to get it right. We don’t want to be standing around in five years saying “why didn’t we do this, why didn’t we do that?”
‘The Medical Officer of Health has just distributed some information about health to all GPs and practice managers. And the PFOS management group [a taskforce set up in response to the concerns] is meeting every two weeks – that is how seriously this is being taken.’
An interim report is currently being prepared by the department and is due to be published next month. It will contain the evidence collected by the investigations so far – sparked after PFOS was found in six boreholes near the Airport earlier this year – and a number of recommendations, ‘from doing nothing to doing lots’, according to Mr Petrie.
‘One of the recommendations undoubtedly will be we need to do even more sampling and do it much more frequently, which will bring some cost implications,’ he added.
Environment Minister John Young has previously said the States might have to consider paying to connect affected borehole users to mains water.
Tests for PFOS have to be sent to a specialist laboratory in the UK and typically take around two weeks to be returned.
Mr Petrie said the high level of the chemical found in the stream near the Airport had been unexpected.
‘We have no idea why [it is so high], which is why we are doing a lot more sampling,’ he said.
‘The most likely source is the Airport, because we know it was in firefighting foam. We will also have to investigate if firefighting foam used elsewhere contained it. There have been some big fires and incidents; we know one was just water but we need to check to rule it [the use of PFOS foam] out.
‘What we are really doing is making sure no stone is unturned this time around.’
According to the health advice sent to GPs, the pollutant is a ‘possible’ carcinogen, with studies linking exposure to it in high levels to high cholesterol, ulcerative colitis, thyroid function issues, testicular cancer, kidney cancer, pre-eclampsia and elevated blood pressure during pregnancy.
Some GPs have already written to Medical Officer of Health Dr Susan Turnbull to say they have been approached by patients with PFOS concerns.
The advice, prepared by the US Centres for Disease Control and Prevention, and described by Dr Turnbull as more up-to-date than UK advice, says that although blood tests can detect PFOS and exposure to other related pollutants, they only show the level at the time of the test and cannot be interpreted and used in patient care. Nor can they predict or rule out the development of future problems related to a suspected exposure.
