Tuesday, May 28, 2013 |
Whether we like it or not, want to believe it or not, or even want to talk about it or not, excrement plays an important role in many aspects of our daily lives. It's been a part of our evolution, it's engrained in our culture, and it's a huge issue for the environment. In his latest book, The Origin of Feces: What Excrement Tells Us About Evolution, Ecology and a Sustainable Society, veterinarian, epidemiologist and professor emeritus at the University of Guelph Dr. David Waltner-Toews says it's time to stop ignoring excrement and deal with it, and even put it to good use. He told Quirks & Quarks host Bob McDonald why waste matters to biodiversity, agriculture, public health, food production and distribution, and global ecosystems.
No matter how much we try to ignore it, excrement plays a huge part in our ecosystem. Every year we produce about 400 million tonnes of excrement from humans and about 14 billion tonnes from animals. All this poop has the potential to have both a positive and negative impact, but it has become a problem because of the way we've structured our cities, trade and livestock. According to Waltner-Toews, there's too much excrement in the wrong places.
"We've concentrated livestock into certain parts of the world and we've concentrated people into urban centres and what that's done is that we get a lot of excrement being produced in those places (as well as milk and food and various other things)." This concentration of people, livestock and excessive excrement leads to public health concerns. But Waltner-Toews has faith in engineers and scientists to deal with this.
Feces often gets a bad rap for being a public health hazard and that's why Dr. Waltner-Toews wants to spread the word on all the positive aspects of excrement: he feels there's a great power in poo. Excrement contains nitrogen, phosphorous, nutrients and many other forms of energy. "You can take cattle manure, for instance, and put it through an anaerobic bio-digester, which basically can produce methane which can be used to produce electricity or can be burned directly," he said.
Cow manure may be the most well-known type of poop but Walter-Toews explained that when excrement is put through an anaerobic bio-digester the harmful bacteria is eliminated. This means all excrement -- even human -- has the potential to be harnessed for energy.
There are also all sorts of creative uses of poop, like elephant dung paper, fish food and even vanilla extract. Dr. Waltner-Toews cited someone in Japan "who was able to extract vanilla from human and animal manure and apparently it uses less energy being extracted from manure than the vanilla bean."
In his book, Waltner-Toews suggests that this is an exciting time for studying excrement, though he also acknowledges some obvious obstacles. "I've got a lot of confidence, engineers are very clever people, they can come up with solutions. I think the biggest problem is the conceptual one: the public acceptance and the way we think about this," he said. "Once we've come up with ways of thinking about this, the engineers can turn around and say, 'we can do that' or 'we can extract this' or 'we can produce energy' or 'we can find other ways to use this material in such a way that it's a benefit to society rather than being a public health hazard or environmental disaster."
It's difficult for people to accept that excrement can be used to power buildings and fertilize our food. But that's partly because of the language we have for excrement. "We have locker room language and we have technical language (like bio solids) and then we've got the kind of back-to-the-land organic humour [but] we don't really have a good public language." Waltner-Toews says it's about finding language for excrement that will reintegrate it into our life and give it its proper place.
He hopes his book will help people stop seeing poop as something disgusting and instead start accepting it as natural and even beautiful. For Waltner Toews, it's "beautiful in terms of being a part of who we are on this planet. And it's not just us but we're part of this very complex web of different life forms and feces/excrement is part of giving back to that larger set of webs -- those ecosystems that then support us in the long run."