Every day we go to the bathroom on average six times. When talking about the ideal space to eliminate our waste, we think of a comfortable white toilet, that flushes efficiently, clean 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 it is urgent to change it.
It is not known with certainty who invented the first device for urinating and defecating. For a long time, no one refrained from dumping their bodily waste on the ground, perhaps behind a small tree. This method was unobjectionable until poop started appearing everywhere. So it was necessary to create a more private and hygienic method. This is how the latrine emerged, which continues to be the toilet for 12% of the world’s population. Latrines are holes in the ground (approximately two meters deep) on which a base is placed to sit on. The waste ends up at the bottom of the hole, where it becomes integrated into the earth. No matter how deep the hole is, at some point it fills up and you have to make another one… and another and another. According to the magazine time, the palace of Knossos 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 smell 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 16th century for Queen Elizabeth I of England. His idea consisted of attaching a seat to a water cistern, all in an enclosed area: water closet, where the acronym WC comes from. Pestilence was the main problem with this design, as it had no way to prevent the backflow of contaminated water. It was the Scottish watchmaker Alexander Cumming who put an end to the problem of bad odours. He achieved this by adding a siphon: an S-shaped tube in whose curvature a volume of clean water is retained, which functions as a plug to prevent the escape of gases. Cumming first patented the toilet in 1775. Almost a century later, English plumber Thomas Crapper began larger-scale manufacturing of toilets, and soon after, in Canada, Thomas Avity added self-cleaning vortex flow (the drop of water spiraling into the interior of the cup that drags waste more strongly). Avity patented this model and thus gave rise to the final design of the contemporary toilet. Now we find them in many colors, materials and styles, but they are all based on this model from more than 100 years ago.
sewage water
What a pleasant feeling to run home in a state of urgency and finally be there: the toilet in front of us, like salvation to our full bladder. And even better, a minute later we pull 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 flush is six liters, 30 liters of water are used to dispose of only two liters of urine. The waste is stratospheric. The number becomes overwhelming when we multiply it by immense families, communities and populations around the world. And the worst thing is that it is potable water: water we could drink.
The common toilet works as a “disappearer” of waste: just pull a lever for it to disappear from 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 tube that normally empties into bodies of water such as rivers and lakes. This, in addition to being a major environmental problem, degrades the quality of life of those who live in areas surrounding contaminated spaces.
According to data from the World Health Organization (WHO) from 2007, in all of 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 reach the environment directly without receiving treatment.
Goodbye excrement, hello diseases
In addition to the enormous waste of water and environmental pollution, there is a less visible but equally important problem: the proliferation of diseases associated with poor hygiene. While the conventional toilet has been the perfect method for eliminating waste for many, 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, under what conditions do these people urinate and defecate? According to WHO data from 2014, 18% of the world’s population defecates in the open (in 1990 the proportion was 31%), 12% do so in inadequate conditions, such as latrines, and 8% use shared spaces. In any of these conditions, good sanitation is not met. This is a central concept that refers to the correct disposal of human excreta to prevent diseases and promote privacy and dignity. 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 come into 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 sources of infection and diseases, especially gastrointestinal. These diseases are transmitted through the fecal-oral route, so called because it occurs when microorganisms from the feces pass into the mouth. This infection mechanism continues to have a negative impact on public health worldwide.
What happens when defecating in the open illustrates how diseases are transmitted if sanitation is lacking. Anyone who defecates on the floor is likely to also not have toilet paper, water or soap, so their hands can become contaminated through direct contact with excreta. With contaminated hands we handle food or put it directly in our mouths. Meanwhile, the flies will come to visit the feces and then begin their flight towards the food, carrying particles of excreta with them. Additionally, direct contact of poop with the ground can contaminate nearby waters, including those we use for cooking. Whether by drinking this water, consuming food with excreta or putting dirty hands directly to our mouth, eventually some people ingest feces that can be accompanied by viruses, bacteria and parasites. If we multiply the effect by millions of people who defecate in the open 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 like Escherichia coli and the Salmonellaviruses like Rotavirus either Calicivirusor parasites like Giardia or helminths are agents that can cause diarrheal diseases. The 760,000 child deaths that occur from diarrhea annually worldwide could be avoided by improving sanitation and other hygiene practices. To achieve this, a toilet design is needed that adapts to varied living conditions, including lack of water and drainage.
In search of the perfect toilet
Therefore, it is urgent to reinvent the toilet. Water-saving toilets (which use six liters per flush instead of 13) have meant an important advance in reducing the waste of liquid, but they do not eliminate it completely and do not address public health problems. Until recently it was almost unimaginable to think of a toilet that worked without water. Today, dry toilets already exist, 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 toilets for almost 30 years. For their part, Cristian Corcuera and Óscar González, industrial designers who graduated from the National Autonomous University of Mexico (), created a toilet design that works without water and that 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 sanitation for many communities. But not only developing countries have paid attention to this new option; The interest in changing the toilet is global. Finland, for example, has a dry toilet association that seeks to promote the development and dissemination of sustainable toilets. But the largest large-scale project 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 child deaths from diarrhea. One of the requirements of the contest was that the toilet function without water. The winner was the California Institute of Technology, with a solar-powered toilet design that generates hydrogen and fertilizer. It is an extremely complex model; requires solar cells and extensive equipment to transform waste. This challenge has reached more countries; China and India were recently summoned. For now, the models born from the contest are very complicated and expensive. However, there are dry toilet designs that have been around for years and that we could adopt.
The dry toilet
Some dry toilets are designed to be integrated into rural areas, but there are also for urban homes. They can be adapted to even an apartment. In general, the operation of a dry toilet, as they are also known, is based on separating urine from excreta, which are dehydrated. The bowl is divided into two sections, one for urine and one for excrement. This is covered with a mixture of dry earth and lime (some mixtures may include ash or sawdust). The objective 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 less than that of land. Lime also works as a deodorant. The section where the mixture-covered excreta is stored should be emptied after several months. It is important to respect this time to allow them to transform and integrate into the land.
Combine the excreta…