Be careful if you go to the beach in the Pacific Northwest; you might get a buzz. Samples of Pacific Ocean water taken off the coast of Oregon reveal surprising levels of caffeine, according to a new study spotted by National Geographic. And no, it didn't get there naturally. Scientists see its presence as a sign that the ocean is being polluted with human contaminants, which, in many cases, wastewater-treatment plants don't test for.
One expert not involved with the study calls caffeine a sort of canary in a coal mine: If it's present, potential contaminants like "pharmaceuticals, hormones, detergents or fragrances, even artificial sweeteners" could be, too. Interestingly, caffeine levels were relatively low near sewage-treatment plants, and relatively high in more remote waters like state parks. "Our hypothesis … is that the bigger source of contamination here is probably on-site waste disposal systems like septic systems," which don't have the same strict water testing requirements, one study co-author explained.