Every day we go on average six times to the bathroom. When talking about the ideal space to eliminate our waste, we think of a comfortable white toilet, that pulls effectively, cleanly and with privacy. This option is much less accessible and modern than it seems. We have been using the same toilet design for a century and urgently need to change it.
Kohler K-4380-0 Memoirs Comfort Height Elongated Bowl, White
It is not known with certainty who invented the first artifact to urinate and defecate. For a long time no one was deprived of dumping their bodily waste on the ground, behind some small tree maybe. This method was unobjectionable until poops began to appear everywhere. Then it was necessary to create a more private and hygienic method. Thus emerged the latrine, which remains the toilet of 12% of the world's population. The latrines are holes in the ground (approximately two meters deep) on which a base is placed to sit. The waste goes to the bottom of the hole, where they are integrated into the earth. No matter how deep the hole, at some point it fills and you have to do another ... and another and another. According to Time magazine, the Knossos palace in Crete, built around 4,000 years ago, was one of the first places with latrines. But in addition to the lack of space to create new holes, latrines have other disadvantages such as bad odor and contamination of groundwater. These deficiencies motivated the design of new systems.
The first toilet was invented by a poet: John Harrinton. He designed it in the sixteenth century for Queen Elizabeth I of England. His idea was to join a seat to a water cistern, all in an enclosed space: water closet, from which the acronym WC comes. The pestilence was the main problem with this design, because it had no way of preventing the backflow of contaminated water. It was the Scottish watchmaker Alexander Cumming who put an end to the problem of bad odors. He achieved this by adding a siphon: an S-shaped tube in whose curvature is retained a volume of clean water that functions as a stopper to prevent the gases from escaping. It was Cumming who first patented the toilet in 1775. Almost a century later, the English plumber Thomas Crapper began the larger-scale manufacture of toilets, and soon, in Canada, Thomas Avity added the flow of self-cleaning vortex (the fall of water in spiral to the interior of the cup that drags with more force the waste). Avity patented this model and thus led to the final design of the contemporary toilet. Now we find them in many colors, materials and styles, but all are based on this model from more than 100 years ago.
sewage water
What a pleasant feeling to get home running in a state of urgency and finally be there: the toilet in front of us, as salvation to our full bladder. And even better, a minute later we pulled and it's as if nothing had happened. Nothing? We dirty and waste between six and 13 liters of drinking water that will go to another place where they will continue their polluting effect.
The maximum volume of urine that we can generate in 24 hours is two liters, which are distributed in about five or six trips to the bathroom. If each discharge is six liters, 30 liters of water are used to discard only two liters of urine. The waste is stratospheric. The figure becomes overwhelming when we multiply it by families, communities and immense populations around the world. And the worst thing is that it is drinking water: water that we could drink.
The common toilet works as a "disappearing" waste: just pull a lever so that they leave our sight. What happens next? The toilet is the beginning of a long journey. With those six or 13 liters of water, the waste passes into a pipe that normally ends in bodies of water such as rivers and lakes. This, in addition to being an important environmental problem, degrades the quality of life of those who live in areas surrounding the contaminated spaces.
According to data from the World Health Organization (WHO) of 2007, in Latin America only 14% of wastewater is treated, and of these, only 6% is treated appropriately. That is, the urine and excreta of 208 million people go directly to the environment without receiving treatment.
Goodbye excrement, hello diseases
In addition to the enormous waste of water and environmental pollution there is a less visible problem, but equally important: the proliferation of diseases associated with lack of hygiene. While the conventional toilet has been for many the perfect method to eliminate waste, for 2.5 billion people in the world the toilet is an inaccessible and even useless option, since they live in areas without water or drainage. So, in what conditions do these people urinate and defecate? According to WHO data from 2014, 18% of the world's population defecates outdoors (in 1990 the proportion was 31%), 12% does it in inadequate conditions, such as latrines, and 8% uses shared spaces. In any of these conditions, good sanitation is not met. This is a central concept that refers to the correct elimination of human excreta to prevent diseases and promote privacy and dignity. In order for sanitation to be adequate, the person must not have contact with their waste, on the contrary, they must be hygienically separated from the human. Currently 2.5 billion people have contact with their waste when urinating and defecating. The most affected countries are concentrated in South Asia and sub-Saharan Africa. Mexico is classified as one of the countries with good sanitation; however, there are still many communities where waste is not disposed of properly. This produces foci of infection and diseases, especially gastrointestinal. These diseases are transmitted through the fecal-oral route, so called because it occurs when the microorganisms in the feces pass into the mouth. This mechanism of infection continues to have a negative impact on public health worldwide.
What happens when defecating in the open air illustrates how diseases are transmitted if sanitation is lacking. Anyone who defecates on the floor is likely to also have no toilet paper, water or soap, so the hands can be contaminated by direct contact with the excreta. With contaminated hands we manipulate the food or we take them directly to the mouth. Meanwhile, the flies will come to visit the feces and then they will fly to the food, carrying with them excreta particles. In addition, the direct contact of the poop with the soil can contaminate nearby waters, including those used for cooking. Either by drinking this water, by consuming food with excreta or by taking dirty hands directly to the mouth, finally someone ingests feces that can be accompanied by viruses, bacteria and parasites. If we multiply the effect by millions of people defecating outdoors daily, the result is a serious public health problem.
Diarrhea is the second cause of mortality in children under five years of age worldwide (WHO 2013) and its origin is the mechanism described. Most of the microorganisms found in feces are harmless, but some affect us terribly. Bacteria such as Escherichia coli and Salmonella, viruses such as Rotavirus orCalicivirus, or parasites such as Giardia or helminths are agents that can cause diarrheal diseases. The 760,000 deaths of children that occur due to diarrhea annually in the world could be avoided by improving sanitation and other hygiene practices. To achieve this, a toilet design is needed that adapts to the varied living conditions, including the lack of water and drainage.
In search of the perfect toilet
So, it is urgent to reinvent the toilet. The water-saving toilets (which use six liters per flush instead of 13) have meant an important advance to reduce the cost of the liquid, but they do not eliminate it completely and do not address the public health problems. Until recently it was almost unimaginable to think of a toilet that would work without water. Today there are already dry toilets, which many countries are considering as a viable option. In Mexico the architect and businessman César Añorve, from Cuernavaca, Morelos, has been dedicated to the production of dry baths for almost 30 years. On the other hand, Cristian Corcuera and Óscar González, industrial designers graduated from the National Autonomous University of Mexico (UNAM), created a toilet design that works without water and uses solid waste to make compost.
In several Latin American countries such as Ecuador, Peru, El Salvador and Haiti, the dry toilet has meant the possibility of improving the sanitation of many communities. But not only the developing countries have paid attention to this new option; the interest in changing the toilet is worldwide. Finland, for example, has a dry toilet association that seeks to promote the development and dissemination of sustainable toilets. But the biggest project on a large scale to reinvent the toilet is the one promoted by the Bill and Melinda Gates Foundation, which in 2011 undertook the challenge of reinventing the toilet, allocating millions of dollars to the best designs. The essential motivation of the contest was to improve the living conditions of the 2.5 billion people without access to safe sanitation and reduce infant death from diarrhea. One of the requirements of the contest was that the toilet will work without water. The winner was the California Institute of Technology, with a toilet design that works with solar energy and generates hydrogen and fertilizer. It is an extremely complex model; it requires solar cells and extensive equipment to transform waste. This challenge has reached more countries; recently they were called China and India. For now, the models born of the contest are very complicated and expensive. However, there are designs of dry toilets that have been around for years and that we could adopt.
The dry toilet
Some dry toilets are designed to integrate them into rural areas, but there are also for urban dwellings. They can be adapted to a department. In general, the operation of a dry bath, as they are also known, is based on separating urine from excreta, which are dehydrated. The cup is divided into two sections, one for urine and another for excrement. It is covered with a mixture of dry earth and lime (some mixtures may include ash or sawdust). The goal is to dehydrate the excrement, and at the same time avoid infectious microorganisms and bad odors. Lime is an alkalizer that is added to the soil to lower the acidity of the excrement. It is included in a proportion 10 times smaller than that of land. Lime also works as a deodorant. The section where the mixed excreta are stored should be emptied after several months. It is important to respect this time to allow them to be transformed and integrated into the earth.
Combining the excreta with the drying mixture results in the formation of a compost that can be used to enrich the soil (it can be added to gardens or pots inside the house), which closes a natural cycle.
Dry toilets have very clear advantages: saving of drinking water, reduction of environmental pollution, generation of useful compost for the land and above all, the possibility that all communities have appropriate sanitation to improve public health. To enjoy these advantages, we must take care different from those we are used to, since a bad use of the dry toilet can lead to serious problems, including bad odors and proliferation of undesirable microorganisms.
The key points to make a good use of a dry toilet are: place it in a well-ventilated place, keep the space always dry (remember that the principle of operation is dehydration), always urinate in the corresponding section to avoid getting wet section of excreta, use a good mixture of lime and earth and meet the emptying times so that the excreta are dehydrated and incorporated into the soil.
The time we spend in the toilet is a valuable moment of privacy. While we sit there, our thoughts flow freely until they are paused when pulling the lever, but in reality there the story begins. With each discharge of the toilet we affect the environment. But for those who do not have an adequate toilet, eliminating their needs means putting their health at risk. Reinventing the toilet represents the possibility of decreasing water waste and, more importantly, of improving public health throughout the world.
-Marra del Carmen Climent Palmer is a veterinary veterinarian from the UNAM, a master in production sciences and animal health; He is currently pursuing a master's degree in science communication at the University of Sheffield, England. In 2014 he won the National Prize for Journalistic Disclosure in Sustainability.