Gates Foundation / Eawag (Swiss Federal Institute of Aquatic Science and Technology)
Gates Foundation / Eawag (Swiss Federal Institute of Aquatic Science and Technology)

5 Toilet Technologies of the Future

Gates Foundation / Eawag (Swiss Federal Institute of Aquatic Science and Technology)
Gates Foundation / Eawag (Swiss Federal Institute of Aquatic Science and Technology)

Most of us take it for granted that we can go #1 or #2 into a lovely porcelain throne, press a lever, and the messy details are taken care of. But for an estimated 2.5 billion people worldwide, a commode is a hole in the ground—at best. And that hole isn't just smelly; it's a source of disease. Here's a roundup of some promising toilet-related technologies that could make pooping safe for the world. All are prototypes today, but could be ready for business soon.

1. Solar-Powered Poop Blaster

System diagram of the poop blaster (technically, "Porta-toilet Facility").

Researchers at Caltech developed a solar-powered waste-treatment system that turns human waste into fuel. The unit is designed to serve as many as 500 people per day, sporting two big benefits: it's powered by the sun; and it produces hydrogen, electricity, and water. (That water can be used for flushing the toilet again.)

How it works: the Caltech design works at the processing end of a conventional toilet/urinal setup. First, waste flows into a holding tank that starts a bacterial digestion process (yes, gross). Then, the waste flows into a a 40-liter electrochemical reactor that uses electrodes to convert it into hydrogen gas. From there, the hydrogen can be used in fuel cells—handy if you have to do your business at night, when the solar array won't produce any juice.

2. Don't Cross the Streams!

Researchers from Eawag pose with their prototype in 2012. (It's intended for use by one person at a time.)

This "three-stream" toilet separates urine and feces using a clever mechanical process.

How it works: When you squat over the toilet, it automatically swivels open and becomes ready for business (this is decidedly unlike the "Honeybucket" open-air poop-pile model you may have experienced at outdoor events...). When you're finished, you work a foot-pump to flush the toilet, and can (optionally) observe your poop's progress through a clear plastic window. Because the waste streams (urine and feces) are separated, they can be treated independently, making the job of waste processing easier. The toilet also automatically recycles water used for flushing, and politely seals itself when you stand up.

Researchers at Eawag (the Swiss Federal Institute of Aquatic Science and Technology) see this toilet being paired with a waste-processing system to make a complete solution for developing countries. Plus, they made their prototype a lovely light blue, making it an appealing place to take a pitstop.

An Eawag toilet being installed in Uganda. Photo courtesy of EOOS/Eawag.

3. Don't Pass Gas, Make Gas

The Delft University of Technology made a proof-of-concept system that turns dried feces into hydrogen gas.

How it works: First the poop is dried out, then it undergoes a plasma gasification process. Gasification is similar to plain old burning, but it happens at much higher temperatures—and with a different goal in mind. Plasma gasification happens at temperatures higher than 2,500°C (!), when an electric current passes through a gas, creating plasma, which in turn is exposed to the pre-dried feces. What you get out the other side is primarily hydrogen, which is then stored in a fuel cell.

Aside from the hydrogen fuel product, this technology is interesting because its super-high temperature promises to kill all pathogens in the feces. That's a big public health bonus!

The plasma gasification reactor.

4. Divert the Urine; Burn the Rest

Researchers at the National University of Singapore focused on the power of pee for their urine-centric fertilizer-creation process.

How it works: Using a urine-diversion toilet, urine is separated from feces. The feces is dried in a solar dryer and then burned. The heat from burning the feces evaporates the urine, which results in two key products: water and fertilizer (urine contains plenty of nitrogen, phosphorus, and potassium—unlike Brawndo, urine's got what plants crave). In the end, you have ash, water, and fertilizer, all of which can be used in agriculture.

One key benefit of this system is that it doesn't require any electricity to operate—it's all manual. That's also arguably a drawback; running the whole thing by hand is a lot harder than many of the automated processes above. Then again, hey, free fertilizer!

The National University of Singapore prototype.

5. The Poop Grinder

The prototype. If you watch the video below, you'll find out where in this contraption the poop goes in and comes out.

Professor A.J. Johannes of Oklahoma State University led a research group to mechanically disinfect poop, making it safer to handle. Well, maybe not to handle, but with.

How it works: Johannes explains, "Feces is a viscous substance. Heat is produced when viscous substances undergo shear." Johannes and his team created a machine in which a cone sits inside a shell; the design is akin to two ice cream cones stacked together. You insert the poop in the gap between the outer cone and the inner cone, rotate the cones, and the poop gets surprisingly hot (as high as 200°C just from shear force produced by rotation) as it passes through. That heat kills a lot of the hazardous stuff living in the poop, thus reducing disease risk from untreated waste. It's energy-efficient, because you simply have to turn the crank, rather than heat the poop directly.

Johannes gave a TEDx talk about his team's progress. It's full of classic science poop jokes, including my favorite: "Plastic is a non-Newtonian fluid...and so is feces." Also, "Mashed potatoes, curiously enough, are very, very similar [to human feces]. I know, I know." Enjoy:

The Real Reason the Lyme Disease Vaccine Had No Shot

With the potential for causing a variety of lingering symptoms ranging from lethargy to nervous system damage, Lyme disease has become a perennial concern for people venturing outdoors in the summer months. Carried by deer ticks, the Borrelia burgdorferi bacteria can challenge our immune systems and prove frustrating to treat. About 30,000 cases are reported to the CDC each year, although the total cases of unreported transmissions could be ten times that number.

So why don’t we have a vaccine for it? We did. And it disappeared.

According to Vox, the spread of Lyme cases in the 1990s compelled pharmaceutical company GlaxoSmithKline to research and develop a vaccine called LYMErix that attacked the outer protein present in the bacteria. It did so by becoming proactively aggressive, killing off the bacteria while it was still in the body of the attached and feeding tick. More than 1.5 million people were given the vaccine before 2000. Clinical trials demonstrated up to a 90 percent success rate.

While that kind of efficacy and protection would be welcome today, at the time doctors weren’t quite certain what kind of demographic they should be recommending the vaccine to: There was less information about regional areas of tick concentrations than there is now. The vaccine also required three doses in the span of a year, making it slightly inconvenient; some health insurers resisted the $50 cost for each injection.

Those issues were surmountable over time. But some members of the Food and Drug Administration (FDA) panel that had approved the vaccine voiced concern that LYMErix might potentially attack healthy proteins in the body. This autoimmune reaction was never demonstrated in trials, but the theory made consumers wary when it was publicized in the media, and some of those treated complained of arthritis symptoms. Coupled with increasing scrutiny and apprehension over vaccines in general, LYMErix failed to become a staple of vaccination schedules. Sales dropped and GlaxoSmithKline stopped production. With the patent having expired, it’s not likely drug companies will be interested in resurrecting it, only to face additional bad press. Alternative vaccines are being considered, but could take years before coming to market.

In the absence of an effective vaccine, the best way to ward off Lyme remains prevention. If you’re going to be in wooded areas where the ticks tend to congregate, wearing light-colored clothing will help you spot the small nymphs. Insect repellent is important, and examining your body—particularly behind the ears and armpits—for ticks after being outside is also a must. If you find one, remove it with a pair of tweezers.

For more information about Lyme disease, check out our 15 Useful Facts.

[h/t Vox]

6 Things You Might Not Know About Ebola

There's been a new outbreak of Ebola in the Democratic Republic of the Congo. Eleven people have been sickened by the disease, and one has died. Here are some things you might not have known about Ebola.


Five species of Ebolavirus have been identified, each named after the place they sprung up: Ebola (formerly Zaire), Bundibugyo, Sudan, Taï Forest, and Reston. All but one—Reston—arose in Africa. The Reston subtype is named after a town in Virginia where an outbreak occurred in 1989, followed by incidents in Texas and Pennsylvania; all three were tied to infected monkeys exported by a single facility in the Philippines. All Ebolavirus species affect people and nonhuman primates—monkeys, gorillas, and chimpanzees—but Reston doesn't cause detectable disease in humans.


Researchers are finding out just how clever Ebola is. One key to its lethal success is the stealth way it shuts down immune system defenses, the same way an air force will disable air defenses before sending in the bombers. Ebola obstructs parts of an immune system that are activated by molecules called interferons. These interferons have a vital role in fighting Ebola, usually with scorched-earth tactics such as apoptosis, or cell self-destruction. A 2014 study found that Ebola disables signals the cells use to defend against its attack using a protein called VP24, which binds to a specific protein that takes signaling molecules in and out a cell's nucleus. Blocked from communication, the cell can't call for help or get the order to self-destruct. The virus then hijacks the cell, uses it to make more viruses, and spreads them to more cells. It also produces ebolavirus glycoprotein, which binds to cells inside blood vessels, increasing their permeability and leading to leakage. This contributes to the catastrophic bleeding characteristic of late-stage Ebola infection.


CDC illustration of cycle of ebola infection from bats to humans and animals

Scientists believe that Ebola's natural host species, or "reservoir hosts," are bats. Infected bats can pass the virus to other mammals, including rats, primates, and us. No one is sure how people first became exposed to Ebola, but the best guess is that monkeys were the conduit. Local hunters in Africa likely became infected while butchering the animals. Anyone who became sick likely infected their family and, if hospitalized in an unsanitary facility, other patients. When the illness spreads from person to person, it does so through direct contact with the bodily fluids of someone who is sick with or has died from Ebola.


It takes the investigative skill of a homicide detective to stop an outbreak. Professionals call it contact tracing. Here's how it works: Ebola victim A is isolated and interviewed. Anyone who had close contact with A is put into quarantine for 21 days. If they exhibit no symptoms, they're free to go when the three weeks are up. If they come down with Ebola, they become victim B, and another contact trace begins. If the investigators miss anyone, the outbreak will continue.


Researchers analyzing the the 2014 outbreak of Ebola in West Africa made a surprising finding: patients who had an active malaria parasite infection were actually more likely to survive the Ebola virus, and by a significant degree. While just over half (52 percent) of Ebola patients not infected with malaria survived, those co-infected with malaria had a survival rate of 72 to 83 percent, depending on their ages and the amount of Ebola virus in their blood. The researchers aren't yet sure why, but the prevailing theory is that malaria somehow modifies the immune response to Ebola by toning down a phenomenon called the "cytokine storm"—the body's own response to an Ebola infection, which inadvertently kills the host while attempting to eliminate the pathogen. If malaria can dampen this response, infected patients may have a better chance of surviving.


We do not yet have a vaccine or antiviral drug to treat Ebola, but many scientists are working to find one. One source is the National Institute of Allergy and Infectious Diseases (NIAID)'s BEI Resources, which gives research facilities access to microbiological materials called reagents that can help them develop diagnostics and vaccines for emerging diseases, including Ebola. Scientists must be registered with BEI to request materials. Reagents are not active viruses, so they can't spread; on the biosafety level, or BSL, scale—which ranks the severity of infectious disease and sets required safety protocols for working with them in a lab—the Ebola-related reagents are considered BLS 1—the lowest risk. (Live Ebola virus is BLS 4—the highest.) Ordering is limited to one Ebola-related reagent at a time, and can be ordered only twice per year.


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