Sanitation

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Example of sanitation infrastructure: Shower, double-vault urine-diverting dry toilet (UDDT) and waterless urinal in Lima, Peru
Example for lack of sanitation: Unhygienic ring-slab latrine in Kalibari community in Mymensingh, Bangladesh

Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes as well as the treatment and proper disposal of sewage or wastewater. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems include human and animal excreta, solid wastes, domestic wastewater (sewage, sullage, greywater), industrial wastes and agricultural wastes. Hygienic means of prevention can be by using engineering solutions (e.g., sewerage, wastewater treatment, stormwater drainage, solid waste management, excreta management), simple technologies (e.g., pit latrines, dry toilets, UDDTs, septic tanks), or even simply by personal hygiene practices (e.g., hand washing with soap, behavior change).

The World Health Organization states that:

"Sanitation generally refers to the provision of facilities and services for the safe disposal of human urine and feces. Inadequate sanitation is a major cause of disease world-wide and improving sanitation is known to have a significant beneficial impact on health both in households and across communities. The word 'sanitation' also refers to the maintenance of hygienic conditions, through services such as garbage collection and wastewater disposal.[1]

Sanitation includes all four of these engineering infrastructure items (even though often only the first one is strongly associated with the term "sanitation"):

  • Excreta management systems
  • Wastewater management systems
  • Solid waste management systems
  • Drainage systems for rainwater, also called stormwater drainage

Despite the fact that sanitation includes wastewater treatment, the two terms are often use side by side: people tend to speak of sanitation and wastewater management which is why the differeantiation is also made in the sub-headings in this article. The term sanitation has been connected to several descriptors so that the terms sustainable sanitation, improved sanitation, unimproved sanitation, environmental sanitation, on-site sanitation, ecological sanitation, dry sanitation are all in use today. Sanitation should be regarded with a systems approach in mind which includes collection/containment, conveyance/transport, treatment and disposal or reuse.[2]

Wastewater management[edit]

Collection[edit]

For more details on this topic, see Wastewater.

The standard sanitation technology in urban areas is the collection of wastewater in sewers, its treatment in wastewater treatment plants for reuse or disposal in rivers, lakes or the sea. Sewers are either combined with storm drains or separated from them as sanitary sewers. Combined sewers are usually found in the central, older parts or urban areas. Heavy rainfall and inadequate maintenance can lead to combined sewer overflows or sanitary sewer overflows, i.e., more or less diluted raw sewage being discharged into the environment. Industries often discharge wastewater into municipal sewers, which can complicate wastewater treatment unless industries pre-treat their discharges.[3]

The high investment cost of conventional wastewater collection systems are difficult to afford for many developing countries. Some countries have therefore promoted alternative wastewater collection systems such as condominial sewerage, which uses pipes with smaller diameters at lower depth with different network layouts from conventional sewerage.

Treatment[edit]

For more details on this topic, see Sewage treatment.

Centralised treatment[edit]

In developed countries treatment of municipal wastewater is now widespread, but not yet universal (for an overview of technologies see wastewater treatment). In developing countries most wastewater is still discharged untreated into the environment. For example, in Latin America only about 15% of collected sewerage is being treated (see water and sanitation in Latin America)

On-site treatment, decentralised treatment[edit]

In many suburban and rural areas households are not connected to sewers. They discharge their wastewater into septic tanks or other types of on-site sanitation. On-site systems include drain fields, which require significant area of land. This makes septic systems unsuitable for most cities.

Constructed wetlands are another example for a possible decentralised treatment option.

Disposal or reuse of treated wastewater[edit]

The reuse of untreated or partially treated wastewater in irrigated agriculture is common in developing countries. The reuse of treated wastewater in landscaping, especially on golf courses, irrigated agriculture and for industrial use is becoming increasingly widespread.

Types of sanitation[edit]

The term sanitation is connected with various descriptors to signify certain types of sanitation systems. Here they are shown in alphabetical order:

Dry sanitation[edit]

The term "dry sanitation" is somewhat misleading as sanitation as includes handwashing and can never be "dry". A more precise term would be "dry excreta management". When people speak of "dry sanitation" they usually mean sanitation systems with dry toilets with urine diversion, in particular the urine-diverting dry toilet (UDDT).[4]

Ecological sanitation[edit]

Ecological sanitation, which is commonly abbreviated to ecosan, is an approach, rather than a technology or a device which is characterized by a desire to "close the loop" (mainly for the nutrients and organic matter) between sanitation and agriculture in a safe manner. Put in other words: "Ecosan systems safely recycle excreta resources (plant nutrients and organic matter) to crop production in such a way that the use of non-renewable resources is minimised". When properly designed and operated, ecosan systems provide a hygienically safe, economical, and closed-loop system to convert human excreta into nutrients to be returned to the soil, and water to be returned to the land. Ecosan is also called resource-oriented sanitation.

Environmental sanitation[edit]

Environmental sanitation is the control of environmental factors that form links in disease transmission. Subsets of this category are solid waste management, water and wastewater treatment, industrial waste treatment and noise and pollution control.

Improved and unimproved sanitation[edit]

Improved sanitation and unimproved sanitation refers to the management of human feces at the household level. This terminology is the indicator used to describe the target of the Millennium Development Goal on sanitation, by the WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation.

Lack of sanitation[edit]

Lack of sanitation refers to the absence of sanitation. In practical terms it usually means lack of toilets or lack of hygienic toilets that anybody would want to use voluntarily. The result of lack of sanitation is usually open defecation (and open urination but this is of less concern) with the associated serious public health issues.

On-site sanitation[edit]

Onsite sanitation is the collection and treatment of waste is done where it is deposited. Examples are the use of pit latrines, septic tanks, and Imhoff tanks

Sustainable sanitation[edit]

Sustainable sanitation is a term that has been defined with five sustainability criteria by the Sustainable Sanitation Alliance. In order to be sustainable, a sanitation system has to be not only (i) economically viable, (ii) socially acceptable, and (iii) technically and (iv) institutionally appropriate, it should also (v) protect the environment and the natural resources.[5] The main objective of a sanitation system is to protect and promote human health by providing a clean environment and breaking the cycle of disease.

Solid waste disposal[edit]

For more details on this topic, see Waste management.

Disposal of solid waste is most commonly conducted in landfills, but incineration, recycling, composting and conversion to biofuels are also avenues. In the case of landfills, advanced countries typically have rigid protocols for daily cover with topsoil, where underdeveloped countries customarily rely upon less stringent protocols.[6] The importance of daily cover lies in the reduction of vector contact and spreading of pathogens. Daily cover also minimises odor emissions and reduces windblown litter. Likewise, developed countries typically have requirements for perimeter sealing of the landfill with clay-type soils to minimize migration of leachate that could contaminate groundwater (and hence jeopardize some drinking water supplies).

For incineration options, the release of air pollutants, including certain toxic components is an attendant adverse outcome. Recycling and biofuel conversion are the sustainable options that generally have superior lifecycle costs, particularly when total ecological consequences are considered.[7] Composting value will ultimately be limited by the market demand for compost product.

Food preparation[edit]

Modern restaurant food preparation area.
For more details on this topic, see food safety.

Sanitation within the food industry means the adequate treatment of food-contact surfaces by a process that is effective in destroying vegetative cells of microorganisms of public health significance, and in substantially reducing numbers of other undesirable microorganisms, but without adversely affecting the food or its safety for the consumer (U.S. Food and Drug Administration, Code of Federal Regulations, 21CFR110, USA). Sanitation Standard Operating Procedures are mandatory for food industries in United States, which are regulated by 9 CFR part 416 in conjunction with 21 CFR part 178.1010. Similarly, in Japan, food hygiene has to be achieved through compliance with food sanitation law.[8]

In the food and biopharmaceutical industries, the term "sanitary equipment" means equipment that is fully cleanable using clean-in-place (CIP) and sterilization-in-place (SIP) procedures: that is fully drainable from cleaning solutions and other liquids. The design should have a minimum amount of deadleg, or areas where the turbulence during cleaning is insufficient to remove product deposits.[9] In general, to improve cleanability, this equipment is made from Stainless Steel 316L, (an alloy containing small amounts of molybdenum). The surface is usually electropolished to an effective surface roughness of less than 0.5 micrometre to reduce the possibility of bacterial adhesion.

Health impacts[edit]

An indicator organism for faecal pollution of water or wastewater: E. coli bacteria under magnification

For any social and economic development, adequate sanitation in conjunction with good hygiene and safe water are essential to good health. Lack of proper sanitation causes diseases. Most of the diseases resulting from sanitation have a direct relation to poverty. The lack of clean water and poor sanitation has caused many diseases and the spread of diseases. Sanitation is very important in order to keep good health. One of the most significant diseases that arise from poor sanitation is diarrhea. Deaths resulting from diarrhea are estimated to be between 1.6 and 2.5 million deaths every year. Most of the affected are young children below the ages of five. Other diseases that are caused by poor sanitation include schistosomiasis, trachoma and intestinal worm infections (helminthiases).

Poor sanitation accounts for almost 50 percent of underweight child since it has a direct link to diarrhea. Children suffering from diarrhea are more vulnerable to become underweight which makes them more vulnerable to other diseases such as acute respiratory infections and malaria. Lack of sanitation is a serious issue that is affecting most developing countries and countries in transition.

The importance of the isolation of excreta and waste lies in an effort to prevent diseases which can be transmitted through human waste, which afflict both developed countries as well as developing countries to differing degrees. It is estimated that up to 5 million people die each year from preventable waterborne diseases,[10] as a result of inadequate sanitation and hygiene practices. The effects of sanitation has impacted the society of people throughout history.[11] Sanitation is a necessity for a heathy life.[12]

Relevant diseases and conditions caused by lack of sanitation and hygiene include:

The list of diseases that could be reduced with proper access to sanitation and hygiene practices is very long. For example in India, 15 diseases have been listed which could be stamped out by improving sanitation:[14]

  1. Anaemia, malnutrition
  2. Ascariasis (a type of intestinal worm infection)
  3. Campylobacteriosis
  4. Cholera
  5. Cyanobacteria toxins
  6. Dengue
  7. Hepatitis
  8. Japanese encephalitis (JE)
  9. Leptospirosis
  10. Malaria
  11. Ringworm or Tinea (a type of intestinal worm infection)
  12. Scabies
  13. Schistosomiasis
  14. Trachoma
  15. Typhoid and paratyphoid enteric fevers

Polio is in fact another diseases which is related to improper sanitation and hygiene.

Improving global access[edit]

The United Nations Millennium Development Goals (MDGs) include a target to reduce by half the proportion of people without access to basic sanitation by 2015. In December 2006, the United Nations General Assembly declared 2008 "The International Year of Sanitation", in recognition of the slow progress being made towards the MDGs sanitation target.[15] The year aimed to develop awareness and action to meet the target. Particular concerns are:

  • Removing the stigma around sanitation, so that the importance of sanitation can be more easily and publicly discussed.
  • Highlighting the poverty reduction, health and other benefits that flow from better hygiene, household sanitation arrangements and wastewater treatment.

The Joint Monitoring Programme for Water Supply and Sanitation of WHO and UNICEF has defined improved sanitation as follows:[16]

The JMP publishes a report of updated estimates every two years on the use of various types of drinking-water sources and sanitation facilities at the national, regional and global levels. In March 2012, the JMP released its latest updates.[17] According to the definition above, 1.8 billion more people used improved sanitation in 2010 than in 1990, bringing the percentage of people using improved sanitation to 63% globally. However, the world remains off track for the sanitation target of the Millennium Development Goals. 2.5 billion lack improved sanitation.[18] According to the JMP, if current trends continue, in 2015 2.4 billion people will lack access to improved sanitation facilities. 15 per cent of the population still practise open defecation, defined as defecation in fields, forests, bushes, bodies of water or other open spaces. This represents 1.1 billion people. Though the proportion of people practising open defecation is decreasing, the absolute number has remained at over one billion for several years, due to population growth.[19] In 2011 the Bill & Melinda Gates Foundation launched the Reinvent the Toilet Challenge to promote safer, more effective ways to treat human waste. The program is aimed at developing technologies that might help bridge the global sanitation gap.

This outcome presents substantial public health risks as the waste could contaminate drinking water and cause life-threatening forms of diarrhea to infants. Most cities can neither afford a sewage drainage system, nor a sewage treatment system, as Sunita Narain spelled out in the magazine D+C Development and Cooperation. Improved sanitation, including hand washing and water purification, could save the lives of 1.5 million children who die from diarrheal diseases each year.[20]

Research from the Overseas Development Institute suggests that sanitation and hygiene promotion needs to be better "mainstreamed" in development, if the MDG on sanitation is to be met. At present, promotion of sanitation and hygiene is mainly carried out through water institutions. The research argues that there are, in fact, many institutions that should carry out activities to develop better sanitation and hygiene in developing countries. For example, educational institutions can teach on hygiene, and health institutions can dedicate resources to preventative works (to avoid, for example, outbreaks of cholera).[21] There are also civil society organisations providing the necessary infrastructure where national governments cannot do that on their own. In Ghana, there is an umbrella organisation for those programmes, called CONIWAS (Coalition of NGOs in Water and Sanitation) as reported in the magazine D+C Development and Cooperation.

The Institute of Development Studies (IDS) coordinated research programme on community-led total sanitation (CLTS) is a radically different approach to rural sanitation in developing countries and has shown promising successes where traditional rural sanitation programmes have failed. CLTS is an unsubsidized approach to rural sanitation that facilitates communities to recognize the problem of open defecation and take collective action to clean up and become "open defecation free". It uses community-led methods such as participatory mapping and analysing pathways between feces and mouth as a means of galvanizing communities into action. An IDS policy brief suggests that in many countries the MDG for sanitation is off track and asks how CLTS can be adopted and spread on a large scale in the many countries and regions where open defecation still prevails.[22]

History[edit]

The earliest evidence of urban sanitation was seen in Harappa, Mohenjo-daro, and the recently discovered Rakhigarhi of Indus Valley civilization. This urban plan included the world's first urban sanitation systems. Within the city, individual homes or groups of homes obtained water from wells. From a room that appears to have been set aside for bathing, waste water was directed to covered drains, which lined the major streets.

Roman cities and Roman villas had elements of sanitation systems, delivering water in the streets of towns such as Pompeii, and building stone and wooden drains to collect and remove wastewater from populated areas—see for instance the Cloaca Maxima into the River Tiber in Rome. But there is little record of other sanitation in most of Europe until the High Middle Ages. Unsanitary conditions and overcrowding were widespread throughout Europe and Asia during the Middle Ages, resulting periodically in cataclysmic pandemics such as the Plague of Justinian (541-42) and the Black Death (1347–1351), which killed tens of millions of people and radically altered societies.[23]

Very high infant and child mortality prevailed in Europe throughout medieval times, due not only to deficiencies in sanitation but to an insufficient food supply for a population which had expanded faster than agriculture.[24] This was further complicated by frequent warfare and exploitation of civilians by autocratic rulers.

References[edit]

  1. ^ who.int
  2. ^ Tilley, E., Ulrich, L., Lüthi, C., Reymond, Ph. and Zurbrügg, C. (2014). Compendium of Sanitation Systems and Technologies (2nd Revised Edition). Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland
  3. ^ Environmental Biotechnology: Advancement in Water And Wastewater Application, edited by Z. Ujang, IWA Proceedings, Malaysia (2003)
  4. ^ "AKUT Sustainable Sanitation in Peru". 13 October 2014. Retrieved 21 October 2014. 
  5. ^ SuSanA (2008). Towards more sustainable sanitation solutions - SuSanA Vision Document. Sustainable Sanitation Alliance (SuSanA)
  6. ^ George Tchobanoglous and Frank Kreith Handbook of Solid Waste Management, McGraw Hill (2002)
  7. ^ William D. Robinson, The Solid Waste Handbook: A Practical Guide, John Wiley and sons (1986)
  8. ^ Japan External Trade Organization. "Food Sanitation Law in Japan" (PDF). Retrieved 1 March 2008. 
  9. ^ Treatment of deadleg plumbing areas
  10. ^ Gleick, P. (2002) Dirty Water: Estimated Deaths from Water-Related Diseases 2000-2020, Pacific Institute for Studies in Development, Environment, and Security
  11. ^ Ehlers, Victor (1943). Municipal and rural sanitation. New York: McGraw-Hill book company, inc. 
  12. ^ George, Rose (2008). The Big Necessity: The Unmentionable Worls of Human Waste and Why it Matters. New York: Metropolitan Books/Henrey Holt and Company. 
  13. ^ WHO (2014) Soil-transmitted helminth infections, Fact sheet N°366
  14. ^ "Article in Hindustan Times: 15 diseases India can stamp out by improving sanitation". 1 October 2014. Retrieved 21 October 2014. 
  15. ^ "Peri-urban Water and Sanitation Services". Springer. 2010. 
  16. ^ WHO and UNICEF types of improved drinking-water source on the JMP website, WHO, Geneva and UNICEF, New York, accessed on June 10, 2012
  17. ^ WHO and UNICEF Progress on Drinking-water and Sanitation: 2012 Update, WHO, Geneva and UNICEF, New York
  18. ^ WHO and UNICEF Progress on Drinking-water and Sanitation: 2012 Update, WHO, Geneva and UNICEF, New York, page 2
  19. ^ WHO and UNICEF Progress on Drinking-water and Sanitation: 2012 Update, WHO, Geneva and UNICEF, New York, page 5
  20. ^ World Health Organization and UNICEF. Progress on Drinking Water and Sanitation: Special Focus on Sanitation.
  21. ^ "Sanitation and Hygiene: knocking on new doors" (PDF). Overseas Development Institute. 2006. Retrieved 2007. 
  22. ^ 'Beyond Subsidies - Triggering a Revolution in Rural Sanitation' Institute of Development Studies (IDS) In Focus Policy Brief 10 July 2009.
  23. ^ Carlo M. Cipolla, Before the Industrial Revolution: European Society and Economy 1000-1700, W.W. Norton and Company, London (1980) ISBN 0-393-95115-4
  24. ^ Burnett White, Natural History of Infectious Diseases

External links[edit]