We Only Think We Flush It Away
The epitome of modern convenience, our toilets make waste disappear with incredible efficiency and ease. We seldom think twice about pulling the lever or about where all that swirls down the pipes ends up afterward. But the massive mazes of sewage pipes underneath our towns and cities ultimately lead to some body of water nearby, and many of these aquatic ecosystems lead to the ocean. We tend to believe that our wastewater treatment plants—the marvels of 21st-century engineering—clean up everything we dish out. Unfortunately, it is a big misconception, in part because the populations grow faster than treatment plants are built, and compounds evolve faster than the cleaning techniques that are designed to filter them.
Our wastewater systems are very efficient at removing pathogens, but not environmental pollutants. Neither do most of them have the right equipment to destroy many pharmaceuticals that come out of us and flow into the seas. Some of these chemicals are so ubiquitous in the ocean that scientists use them as indicators of how far contamination spreads, says Stephanie Wear, marine biologist and founder of Ocean Sewage Alliance, a nonprofit that aims to “re-potty train the world.” In her recent study published in Biological Conservation, Ware’s team used diclofenac—an anti-inflammatory drug which persists in the water for weeks to months—to map how far sewage pollution spreads.1 As these chemicals float in the water, they smother corals, poison fish, kill mangrove forests, and destroy coastal marshes. “We found that 31 percent of salt marshes globally were heavily polluted with human sewage,” Wear says. “We are destroying the ocean with our pollutants.”
How much caffeine is deadly for aquatic species?
Plastic, as we know, is, we dump about 10 million metric tons of plastic into the ocean every year. By 2050, plastic will in the seas. We don’t flush plastic water bottles, for instance, down the toilet. But we do flush microplastics. We every week, which find their way into waterways and the ocean, into fish, and back into us. Plastic gets the headlines but it’s not the whole story. Our sewage is a noxious cocktail of chemicals that are coming back to us like a toxic tsunami. Widespread ocean pollution threatens the health of over 3 billion people, points out Phillip Landrigan, epidemiologist at Harvard T.H. Chan School of Public Health, and a corresponding author of a recent that depicts the harmful and deadly effects of these contaminants. Here are eight contaminants circulating in that surging tide, if you dare to dive in.
