Sewers produce caffeine jag

Researchers at the Norwegian Institute for Air Research have found traces of caffeine and other drugs in drainage water and the sea near Tromsø in northern Norway.

Caffeine and drugs flushed into city sewers may take longer to break down in icy Arctic waters than further south, which may explain why the levels of pharmaceutical residues matched those expected for a city three times the size of Tromsø.

Each liter of water discharged from Tromsø contained up to 100 micrograms of caffeine. In the sea the concentration was measured at 100 nanograms per liter.

“The concentration is high. We are surprised that caffeine is not more diluted by the high volume of water,” researcher Roland Kallenborn told the Aftenposten newspaper. “Caffeine is not caught by purification plants and there is a high and continuous supply entering the sea.”

Caffeine is found in coffee and cola as well as some medicines. Researchers believe that about 80 per cent of caffeine comes from households, offices and cafés, with medicines accounting for the rest.

“We have almost no information about what kind of problems caffeine can cause in nature. It is a poison and at very high concentrations it can affect the nervous system. We don’t know the kind of environmental effect caffeine can have on the ecosystem and this is something that should be thoroughly investigated,” Kallenborn said.

Some samples taken very close to a sewer outlet near a psychiatric hospital also showed measurable amounts of anti-epileptic drugs and anti-depressants.

Tromsø sea water contained measurable traces of ibuprofen, an anti-inflammatory drug often used to treat arthritis.