Human Nature: Science, Technology, and Life.

Bottoms Up

"Cheers!" say the astronauts.

"Cheers!" shout the engineers watching from mission control.

They all hoist their brew. The engineers down it. The astronauts sip and smile. "The taste is great," exclaims one astronaut.

The video, filmed aboard the International Space Station and posted on NASA's Web site, looks like a beer commercial. Or maybe a plug for Tang, the powdered soft drink made famous by the U.S. space program. But it's neither. It's an ad for what everybody in the video is drinking: recycled urine.

Mmmmmm. Urine.

Three years ago, this was part of NASA's plan for "Environmental Control and Life Support Systems." Today, it's the "Water Recovery System." According to the Associated Press, "When six crew members are aboard it can make about six gallons from urine in about six hours." NASA explains:

A distillation process is used to recover water from urine. The process occurs within a rotating distillation assembly that compensates for the absence of gravity, aiding in the separation of liquids and gases in space. Once distilled, the water from the urine processor is combined with other wastewaters and delivered to the water processor for treatment. The water processor removes free gas and solid materials such as hair and lint, before the water goes through a series of filtration beds for further purification. Any remaining organic contaminants and microorganisms are removed by a high-temperature catalytic reaction. These rigorous treatment processes create water that meets stringent purity standards for human consumption.

In case the astronauts' smiles don't convince you, the space station's lab manager points out something else: "Some people may find the idea of drinking recycled urine distasteful, but it is also done on Earth, but with a lot longer time between urine and tap."

That's right: You already drink toilet-to-tap water. Urine evaporates, rain falls, rivers flow. And that's not even counting the free-flowing sewage. As proponents of water recycling elegantly put it: What happens in Vegas doesn't stay in Vegas.

The space station is just a smaller world. There, the Water Recovery System "is tied into the station's Waste and Hygiene Compartment toilet" directly. It's a microcosm of what happens naturally on Earth—and what we'll increasingly have to accelerate, through artificial filtering, as we overtax our planet's fresh water supplies.

That's why those astronauts in the video are effusing about the taste of recovered water and wearing goofy, happy-customer grins. They really are making a commercial. It's for the water of the future, in space and here on Earth.

Tang, anyone?

Fecal Fuel

Several days ago, we looked at "toilet to tap," the increasingly useful art of turning sewage into drinking water. Orange County, Calif., which is pioneering the practice, is proud to tell you how thoroughly its filtration purges the sewage: "Thousands of microfilters, hollow fibers covered in holes one-three-hundredth the width of a human hair, strain out suspended solids, bacteria and other materials."

But what if the water isn't what you want? What if you want the sewage?

Who would want these lovely "suspended solids," you ask? Why, you would. Apparently, they're a fine source of environmentally friendly fuel. Agence France Presse reports that in Oslo, Norway,

city officials soon plan to introduce buses that run on biofuels extracted from human waste. ... The biofuel, which is methane generated by fermenting sludge, will come from the Bekkelaget sewage treatment plant which handles waste from 250,000 city dwellers. "By going to the bathroom, a person produces the equivalent of eight litres (2.1 gallons) of diesel per year. That may not seem like a lot, but multiplied by 250,000 people, that is enough to operate 80 buses for 100,000 kilometres (62,000 miles) each," [one official] says.

Fecal fuel is, if you'll pardon the expression, green:

In addition to being carbon neutral, it emits 78 percent less nitrogen oxide and 98 percent fewer fine particles—two causes of respiratory illnesses—and is 92 percent less noisy. ... "If our entire fleet switched to biomethane, carbon dioxide emissions would be reduced by around 30,000 tonnes per year," according to [an Oslo official].

It protects the food supply:

Contrary to first generation bio-ethanol, made from grains and plants, biomethane has the added advantage of not impacting food supplies, nor does it require fertilisation or deplete precious water resources.

In other words, instead of turning corn into fuel, which prevents you from eating the corn, we should feed you the corn first and then collect your droppings so that your sustenance becomes part of the fuel production process.

And it's cheap:

All included, the cost of producing biofuel equivalent to one litre of diesel comes to 0.72 euros (98 cents), while diesel at the pump in Norway currently costs more than 1.0 euro.

In fact, as a fuel supplier, maybe you should get a cut of the savings. Remember that pilot project in India I mentioned last year? The one where villagers get paid to use public toilets while their urine is tested for use as a fertilizer? At the time, I proposed that

we could try our own version of the Indian experiment. To do that, we'd need to devise an efficient method of converting public-toilet waste into something productive, such as fertilizer, without endangering public health. ... I bet somebody will figure out pretty soon how to monetize toilet waste. ... Restaurant grease [is] being illegally siphoned from filthy bins and barrels. Bandits are selling it for conversion to biodiesel. When bandits start siphoning public toilets, maybe governments will wake up and get in on the action. And you'll stop having to pay.

Nine months later, Oslo may have worked out the last piece of the puzzle. You go to the bathroom. We filter the excrement from the water. We recycle the water so you can drink it again. Meanwhile, we turn the excrement into fuel. All of this helps the environment, protects the food supply and saves money. And if you play it right, you get paid.

Anyone got a problem with this?

You Already Drink Crap

It's been a year or so since we checked in on "toilet to tap," the increasingly useful art of turning sewage into drinking water. Actually, you aren't supposed to call it "toilet to tap." That's a slur coined by political opponents of the technology. And it's highly effective, as evidenced by the fact that I've probably grossed you out already.

The technology's proponents constantly labor to explain how sanitary it is. Their latest attempt, via Reuters, focuses on Orange County's "Groundwater Replenishment System":

Anyone who has visited Disneyland recently and taken a sip from a drinking fountain there may have unknowingly sampled a taste of the future—a small quantity of water that once flowed through a sewer. ... The plant takes pre-treated sewer water that otherwise would be discharged to the ocean and runs it through a three-step cleansing process—essentially the same technology used to purify baby food and bottled water. Thousands of microfilters, hollow fibers covered in holes one-three-hundredth the width of a human hair, strain out suspended solids, bacteria and other materials. The water then passes to a reverse osmosis system, where it is forced through semi-permeable membranes that filter out smaller contaminants, including salts, viruses and pesticides. Reverse osmosis also is the main process used in desalination.  Finally, the water is disinfected with a mix of ultraviolet light and hydrogen peroxide. The resulting product exceeds all U.S. drinking standards but gets additional filtration when it is allowed to percolate back into the ground to replenish the aquifer.

Well, that sounds pretty clean. But I bet you're still not convinced. You'd rather stick to the familiar crap-free water that already comes from your tap.

Surprise! That familiar water isn't so crap-free after all. And proponents of the new technology are happy to tell you so:

They want the public to understand that much of what comes from the tap today is recycled sewer water. The Colorado River, for example, contains large amounts of heavily treated waste discharged from cities upstream, including Las Vegas. As the L.A. County Economic Development Corp study puts it, "What happens in Vegas doesn't stay in Vegas."

Great line. And it's smart politics: If you can't sell the public on the purity of your own candidate, attack the other side's candidate. We're used to this tactic when the candidates are people like John McCain and Barack Obama. But it works just as well when the candidates are groundwater replenishment and old-fashioned tap water.

And just because this is a political attack doesn't mean it's false. For my money, it's true. We already drink toilet-to-tap water. That's the nature of water: It cycles from one form to another. Urine evaporates, rain falls, rivers flow. If you think you've never consumed water that came from excrement, you must literally be living on another planet.

So stop freaking out about where your water came from, and start focusing on the quality of its filtration. Everything is recycled, including you.

Contrarianism in Context

Impressive cluster of contrarian research in today's batch: Coffee can help prevent Alzheimer's; trans fats can be good for you; fat kids have fewer cavities; and the alleged benefits of drinking lots of water are unfounded. I love reports like these. I've flagged and commented on lots of them in the previous Human Nature news roundups. Part of it is that I just enjoy contrarianism. Part of it is that discoveries like these expose our overconfidence about what we know. Biology is enormously complex. Sometimes extra weight is bad for you; sometimes, at death's door, it can save your life. We vilify and prohibit alcohol as a sin, then discover it can help your circulation.

But I don't want to let the mischievous fun of medical contrarianism obscure reality. The reason why studies like these are surprising and intriguing is that they generally run against the grain of biology. By and large, trans fats are horrible for you. Relying on coffee instead of sleep for daily energy is dangerous. And even if being fat somehow improves your kid's dental health, the damage done to the rest of his body isn't worth it.

When you see a report about the benefits of booze or chocolate, always remember that the reason it's worth a headline is that these things, in their usual form and consumed quantity, are generally unhealthy. Not a very entertaining takeaway, I admit. But true.