Along with the usual spooky and spine-tingling sights we have come to expect in caves, another scary inhabitant is turning up — contaminants such as PCBs, pesticides, dioxins, gasoline, fertilizers, sewage, and caffeine.
These pollutants, which are leaching into caves from the surface and groundwater, can pose a threat to the delicate underground environments that are prized by many, and that provide benefits to people, plants, and animals on the surface. The presence of these contaminants underground also serves as a blunt reminder of how pervasive pollutants are.