The term open defecation became commonly used after
the UN observed the International Year of Sanitation
in 2008 and the first annual World Toilet Day in 2013.
It refers simply to people defecating outdoors, in fields, streams, or
alleyways, and not into toilets.
The World Health Organization estimated in 2014 that about 1 billion people, 15% of the global population, practice open defecation.
WHO/UNICEF Progress on Drinking Water and Sanitation, 2014 As for specific countries, India has the highest number, about 490 million people. They estimate that 52% of the rural population does it, and 7.5% of the urban population. Then it's Indonesia with 54 million, Pakistan with 41 million, and Nigeria with 39 million, and Ethiopia with 34 million.
Open defecation is a huge public health problem in densely populated areas.
The WHO report found that open defecation is correlated with child mortality and undernutrition. It's largely driven by economic pressures, as it's found more in countries with high levels of poverty and wide disparity between the wealthy and the poor.
Times Indian Prime Minister Narendra Modi famously called for "Toilets first, temples later" in a speech in 2013, pledging to eliminate open defecation in India by 2019. The Hindu reported in early 2016 that this would require building "nearly 12 crore toilets", with a crore denoting ten million or 107 in the Indian numbering system for a total of 120,000,000 new toilets.
If You End Open Defecation, Then What?
Bangladesh has made stunning progress toward ending open defecation. The World Bank estimates that open defecation has dropped from 34% of Bangladeshi citizens in 1990 to just 1% nationwide in 2017. With a population estimated at 163 million in 2017, that means that over 50 million people stopped defecating in public during that period.
That's great news for public health and human dignity! Bangladesh has the tenth highest population density worldwide, 1,126 people per square kilometer, ranking behind only city-states or small island nations, so open defecation has been an especially bad problem there.
But how does an underdeveloped country handle an enormous surge in collected human waste?
Emptying the Pit Latrines
Bangladesh made most of their improvement by constructing about 400 million new pit latrines. The pits fill and then must be emptied, every three to four years or so. It costs roughly US$ 13 to have a pit latrine emptied. That's about 14% of an average rural family's monthly income.
The initial solution was to hire a local crew of young men to use shovels and buckets to empty the latrine pit. That is a slow, messy, and smelly process, and the work crew disposes of the sludge close to the household, very often by dumping it into a nearby waterway.PLOS ONE paper
A recent paper in the PLOS ONE journal reports a promising study: "Towards sustainable sanitation management: Establishing the costs and willingness to pay for emptying and transporting sludge in rural districts with high rates of access to latrines"
That paper came out in March 2017, its authors are with the International Water Management Institute in Pelawatte, Sri Lanka, the NGO Forum for Public Health in Dhaka, Bangladesh, the Bangladesh University of Engineering and Technology, Dhaka, Bangladesh, the University of Leeds, Leeds, U.K., and the Unversidad Nacional de Colombia, Manizales, Colombia.Science paper
That follows a 2015 paper in Science by professors of economics and management at Yale University, New Haven, CT, USA, "Encouraging sanitation investment in the developing world: A cluster-randomized trial".
The Mathematics of Human Waste"The Characterization of Feces and Urine: A Review of the Literature"
Thanks to a 2015 journal article, we know that an average adult human excretes 128 grams of feces per day. The feces are about 75% water. The organic solids consist largely of bacterial biomass (25-54% of dry solids). The remainder is undigested carbohydrate, fiber, protein, and fat, plus calcium and iron phosphates, intestinal secretions, small amounts of dried epithelial cells, and mucus.
The PLOS ONE paper estimates that sludge accumulates at 0.11 liter per person per day, and a typical pit latrine must be emptied about every three to four years. The researchers and the Government of Bangladesh set up a pilot program in the rural subdistrict of Bhaluka. The literacy and school attendance rates are both slightly below 50%, below the national averages.
The pilot program use pumps to empty latrines. A survey of local latrine pit emptiers followed by testing in the field showed that non-powered hand-held diaphragm pumps were the best solution. These pumps move the sludge into plastic barrels carried on small trucks.
The program established a monthly payment system about 24 Bangladeshi Taka per month, the equivalent of about US 0.31.
They calculated that the subdistrict's 77,413 households would need about 20,760 emptying events per year, yielding 15,219 cubic meters of sludge every year. The scale of the program allows for a very slightly smaller overall cost over the years to the latrine owner, while sending the collected sludge into a composting system to convert the sludge into fertilizer for non-edible plants.
Is It Worth It?
The local residents in Bangladesh said "yes", if the monthly cost is low enough. The key is to make it a monthly service, not a large cost every three to four years. The study found a way to get the monthly cost down to where it is only slightly higher per year than mobile phone service. As another benefit, the program created jobs in the subregion.
The authors of the Science paper also did their research in Bangladesh. They studied over 100 small villages in the poor rural district of Tanore, where about a third of adults practice open defecation or use nonhygienic "hanging latrines", small privies on poles that dump feces into a body of water They concluded that economic subsidies from the government "may undermine intrinsic motivation or cause dependency."
If the main constraints are poverty, subsidies are necessary. But if the main constraints are lack of information about the benefits of sanitation combined with broad acceptance of open defecation, then the best solution would be to provide information and create social pressure. The reality is that subsidies, education, and social pressure are all needed.
A state government in India has an interesting idea for increasing social pressure against open defecation.
Indian Children Blow the Whistle on Open Defecation
The Singapore Straits Times reported in 2014 that the Madhya Pradesh state government in central India was enlisting children to shame people who are defecating in the open.
The government gave whistles to the children, asking them to blow their whistles loudly when they saw someone squatting in the open.
Narendra Modi, the Prime Minister, said that shared toilets were being constructed, and that every household should have their own toilet within four years.
However, even with proper toilets, open defecation has become a part of the culture. Many people prefer to defecate in the open even when a clean and safe toilet is available.