The Global News Source for the World of Science
21 June 2017Lab Chat
Whether it’s an espresso in the morning, a cappuccino at lunch or a constant stream of instant through the day – most of us drink coffee. It gets people out of bed, and keeps them alert through the day. It’s so ingrained in most societies that scientists have even looked into ways of brewing the “ideal coffee”. But could your daily habit be causing damage to the environment? Read on to see the potential hidden impact of your rich roast.
Coffee isn’t just a great taste. Most varieties of the hot brew contain a decent amount of caffeine. As most coffee-drinkers know, caffeine is a psychoactive substance that gently stimulates your central nervous system. In fact, it’s the most widely used psychoactive drug in the world, probably because in most parts of the world it’s completely legal.
However, as with some vitamins and nutrients, the body can only consume so much caffeine. When there is too much taken in, the excess leaves the body in urine. With some coffee, like the strongest variety in the world, the excess could be a pretty hefty amount. When it leaves, the process is complete for the coffee drinker. The problem is what happens to this caffeinated urine after it leaves.
As with all sewage, the urine travels to sewage systems to be treated. In an ideal world, this would be the end of it. However, a new study has found something a bit different. A team of researchers from the Water Quality Control Board in San Diego collected samples from water sources across the region between 2008 and 2015. As expected, they found that urban water had traces of caffeine, but more unexpectedly was the result in rural streams.
They discovered traces as high as 0.662 micrograms per litre in rural streams. That’s around 10 percent as strong as the concentration in untreated sewage. Because there are no natural sources of caffeine in the surrounding area, they put it down to urine.
The problem with caffeine entering rural areas is when it comes into contact with the surrounding wildlife. Mussels around certain streams produce a DNA-protecting protein to stay alive. Further tests found that mussels around the affected areas were unable to produce the protein as the caffeine but their cells under too much stress. It’s thought that these levels of caffeine in rural waters could put mussels, and possible other species, at risk of genetic mutation.