River Thames polluted beyond rescue

The levels of nitrates in the River Thames are so high they might be beyond rescue, with environmental reporters suggesting a full scale change of land use and management would be required, which could compromise food security and take decades to implement.

UK researches have conducted the longest continuous record of river water chemistry in the world to find their results, which show that nitrate levels have trebled since the 1930s. The intensive agriculture, made possible by modern fertilisers, has lead to 'intractable environmental problems' such as soil erosion and water pollution.

Dr Nicholas Howden from the University of Bristol, commented: "Our results suggest it could take several decades for nitrate levels to drop even with significant changes to land management practices."

The study outlines the challenges in feeding an increasing population as well as providing clean drinking water. Aquifers in the Thames river basin supply around five million people with drinking water, but another six million rely on water taken from the river.

The increased nitrate concentration also impacts on marine life, triggering a rapid growth in algae that cut oxygen supply to the waters.