Perhaps you've seen the video on Mr. Toilet, a short film on a man trying to make the toilet a status symbol in poorer parts of Asia. Perhaps you've heard of the problems with water contamination in many parts of the world. Perhaps you've only encountered the occasional E. coli scare when it gets broadcast on the news ... which is frequently. One would imagine that by now, after several thousand years of "civilized" living, we would have learned how to manage excrement so that it does not impact our own health. It seems like access to clean water is a basic human right, not just in the U.S. but worldwide.
The problem is, waste is frequently overlooked. I, for example, had no awareness of what a septic system entailed until I encountered the slow moving toilets at camp one summer, or even where the stuff in most toilets goes. Most humans are disgusted by the thought of your food once it has passed through the stomach. This is, after all, an evolutionary trait. The sense of disgust we feel when we consider fecal matter is a deterrent, most likely evolved to reduce animals consuming their own feces and becoming ill.
I had the pleasure of listening to a talk from Dr. Kyle Van Houtan, who has been researching a potential link between nitrogen output on the Hawaiian islands and tumor growth on turtles. I was first surprised to learn that it's common practice in Hawaii to dispose of waste using sewage injection wells. This is almost certainly what it sounds like: Wastewater is collected and sent into the ground using deep pits below the groundwater. The research conducted in the 70's and 80's, when this method became popular, did not show any particularly intense impacts on the groundwater.
However, as Dr. Van Houtan pointed out, the Hawaiian islands were formed by volcanoes. This means that the geology of the island is porous, so that the small holes in the bedrock may allow more transport than expected. The toxins in the waste may be escaping from these wells in unprecedented ways. We've been looking for ways that these wells would impact the ocean surrounding the islands, and we've overlooked how they may be changing the quality of the water table.
What makes Van Houtan's research fascinating is how he traced the nitrogen from waste management to a herpes virus he has been studying in sea turtles. The excess nitrogen from human waste encourages invasive macroalgae to bloom in massive quantities. Sea turtles proceed to feed on this nitrogen rich algae. Van Houtan's discussion showed a correlation between the elevated nitrogen levels in the algae and the turtles' elevated levels of arginine, a nitrogen rich amino acid. Arginine impacts immune responses, as well as promoting herpes viruses and tumor growth. In essence, our poorly handled waste may be encouraging the demise of an already threatened species of iconic megafauna, as well as impacting our own water quality.
If this level of contamination occurs in the U.S., where clean water is copious, I can only imagine the impacts of poor waste management in other parts of the world. We need more people like Mr. Toilet, encouraging us to talk about poop, where it's going, where we're putting it. While it may be disgusting, it's far less disgusting to take care of waste before it spreads contamination and becomes a far greater problem.