PFOS levels in Guernsey drinking water safe, finds report
Guernsey and Alderney tap water is safe to drink despite containing traces of a firefighting chemical, says a report.
Perfluorooctane sulfonic acid (PFOS), which was previously used by the airport fire services in both islands, was first found in water in 2007.
In drawing up its report, the UK Health Protection Agency said it was safe but the human health effects of exposure to PFOS had not been fully investigated.
There are no internationally agreed safe levels for PFOS in drinking water.
Guernsey Water spends about £25,000 a year on monitoring levels in the island's water supply, having adopted guidelines form the Drinking Water Inspectorate for England and Wales.
The agency found levels in Guernsey have been gradually falling over the last five years while those in Alderney have remained roughly the same.
'Leaked into soil'
The report said: "The levels of exposure to PFOS in the drinking water in Guernsey and Alderney are not expected to result in ill health for the population.
"However, the information available on the human health effects of PFOS exposure is still not conclusive and existing studies have suggested that PFOS may have effects on cholesterol and thyroid hormone levels," it added.
"Local remedial actions taken by the authorities to date have been necessary to reduce any potential risk."
The agency found the places where the substance had leaked into soil were mostly within the boundaries of the airports.
Soil contaminated when a fire truck overturned on Guernsey's runway in 2002 has been removed and sealed in a bund by the airport entrance.
PFOS was used to tackle a fire caused by after a plane crash in 1999 and the soil in the field where it happened is due to be removed and sealed in a smaller bund next to the other one.
Deputy David De Lisle, who has previously raised concerns about the substance, said the independent report had not convinced him local drinking water was entirely safe.
He said the UK standards relating to PFOS were not as stringent as those in the United States and he would like those standards to be adopted in the islands.