National Geographic: The Pacific Northwest may be the epicenter of U.S. coffee culture, and now a new study shows the region's elevated caffeine levels don't stop at the shoreline. The discovery of caffeine pollution in the Pacific Ocean off Oregon is further evidence that contaminants in human waste are entering natural water systems, with unknown consequences for wildlife and humans alike, experts say.
Scientists sampled both "potentially polluted" sites—near sewage-treatment plants, larger communities, and river mouths—and more remote waters, for example near a state park.
Surprisingly, caffeine levels off the potentially polluted areas were below the detectable limit, about 9 nanograms per liter. The wilder coastlines were comparatively highly caffeinated, at about 45 nanograms per liter.