The chair of a Suffolk river preservation group has spoken of his concern that toxic man-made chemicals linked to cancers and thyroid disease have been found in the water.

Dr John Warren, chair of the River Gipping Trust, has called for more effective monitoring of the health of river waters after it was revealed that five chemicals had been released into the Gipping close to where it meets the River Orwell.

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Among the chemicals discovered close to the Hadleigh Road industrial estate was Perfluorooctanoic Acid, which is used in industrial chemical processes.

However, studies have linked the acid to kidney and testicular cancer, as well as diseases such as ulcerative colitis, thyroid disease and pregnancy-induced hypertension.

Other harmful contaminants included Perfluorooctane Sulfonate, which is found in fish and a chemical used in firefighting foams, Perfluorohexane Sulfonate, which was added to the United Nations' Stockholm Convention on Persistent Organic Pollutants.

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The convention seeks to reduce the impact of harmful pollutants in the environment.

East Anglian Daily Times: Dr John Warren (centre) at the unveiling of a restored footbridge at Baylham on the river GippingDr John Warren (centre) at the unveiling of a restored footbridge at Baylham on the river Gipping (Image: River Gipping Trust)

The chemical Perfluorooctane Sulfonate was also discovered further up the river at Sproughton Mill, which was used in stain repellent products and was banned by the European Union for use in most products in 2006.

Dr Warren said he was "concerned'"about the situation and called for greater monitoring.

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He said: "Five toxic man-made chemicals have been detected in the River Gipping that do not occur naturally and were not in production before 75 years ago.

"Most of these are now widespread in the environment in many parts of the world and in human populations.

"Some can last for years in humans. Multiple toxic effects have been described and the tendency of regulations in recent years has been to lower considerably the concentrations that are considered the maximum safe level.

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"Much research has been done on the potential toxicity of the individual chemicals, though little is known about how this profile changes when we are exposed to combinations of different chemicals.

"One thing we can be sure about is the need to support improved effective monitoring of the health of our rivers and drinking water."