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 wastewater. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems include human and animal feces, solid wastes, domestic wastewater (sewage, sullage, greywater), industrial wastes and agricultural wastes. Hygienic means of prevention can be by using engineering solutions (e.g. sewage and wastewater treatment), simple technologies (e.g. latrines, septic tanks), or even by personal hygiene practices (e.g. simple handwashing with soap).
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]The term sanitation is applied to a wide range of subjects such as:
- Improved sanitation - refers to the management of human faeces 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.
- On-site sanitation - the collection and treatment of waste is done where it is deposited. Examples are the use of pit latrines, septic tanks, and Imhoff tanks.
- Food sanitation - refers to the hygienic measures for ensuring food safety.
- Environmental sanitation - 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.
- Ecological sanitation - an approach that tries to emulate nature through the recycling of nutrients and water from human and animal wastes in a hygienically safe manner.
History
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.[2]
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.[3] This was further complicated by frequent warfare and exploitation of civilians by autocratic rulers.
Sanitation refers to the safe disposal of human excreta (Mara, Lane and Scott and Trouba,1). This entails the hygienic disposal and treatment of human waste to avoid affecting the health of people. Sanitation is an essential part of the Millennium Development Goals. The most affected countries are in the developing world (Zawahri, Sowers, and Weinthal 1153). Population increase in the developing world has posed challenges in the improvement of sanitation (Konteh 69). According to Zawari, Sowers, and Weinthal (1154), lack of provisions of basic sanitation is estimated to have contributed to the deaths of approximately 3.5 million people annually from water borne diseases.
Wastewater
Wastewater collection
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.[4]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 smaller diameter pipes at lower depth with different network layouts from conventional sewerage.
Wastewater treatment
In developed countries treatment of municipal wastewater is now widespread,[5] 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)
Health Impacts of Sanitation
For any social and economic development, adequate sanitation in conjunction with good hygiene and safe water are essential to good health (Mara, Lane and Scott and Trouba 1). 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 (Mara, Lane and Scott and Trouba 2). Most of the affected are young children below the ages of five. Other diseases that are caused by poor sanitation include schistosomiasis, trachoma, and soil transmitted Helminthiases.Poor sanitation accounts for almost 50 percent of underweight child since it has a direct link to diarrhea. Children suffering for diarrhea are more vulnerable to become underweight. According to Mara, Lane, and Scott and Trouba (3), about 26 percent acute respiratory infections occur in children who are malnourished, which has a direct link to diarrhea. Sanitation is a serious issue that is affecting most parts of the world especially the developing countries. On a global scale, the most affected are children who in most cases lose their lives due to diseases caused by poor sanitation. Major initiatives need to be set up if the MDG goal on sanitation is to be achieved by 2015.
On-site treatment
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.Reuse of wastewater
The reuse of untreated 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.Ecological sanitation
Ecological sanitation is sometimes presented as a radical alternative to conventional sanitation systems. Ecological sanitation is based on composting or vermicomposting toilets where an extra separation of urine and feces at the source for sanitization and recycling has been done. It thus eliminates the creation of blackwater and eliminates fecal pathogens. If ecological sanitation is practiced municipal wastewater consists only of greywater, which can be recycled for gardening. However, in most cases greywater continues to be discharged to sewers.Sanitation and public health
The importance of the isolation of 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 water-borne diseases,[6] as a result of inadequate sanitation and hygiene practices.The effects of sanitation has impacted the society of people throughout history.[7] Sanitation is a necessity for a heathly life.[8] The results of studies published in Griffins Public Sanitation show that better sanitation produces an enhanced feeling of wellbeing.[citation needed]Relevant disease include:
- Waterborne diseases, which can contaminate drinking water
- Diseases transmitted by the fecal-oral route
- Hookworm, where eggs can survive in the soil
Global access to improved sanitation
The Joint Monitoring Programme for Water Supply and Sanitation of WHO and UNICEF has defined improved sanitation as follows:- Flush toilet[12]
- Connection to a piped sewer system[13]
- Connection to a septic system[14]
- Flush / pour-flush to a pit latrine[15]
- Ventilated improved pit (VIP) latrine[16]
- Pit latrine with slab[17]
- Composting toilet[18]
- Some special cases[19]
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.[23]
Solid waste disposal
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.[24] 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 life cycle costs, particularly when total ecological consequences are considered.[25] Composting value will ultimately be limited by the market demand for compost product.
Food preparation
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.[26]Additionally, 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[27] or areas where the turbulence during cleaning is insufficient to remove product deposits. 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.
Improving access
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.[28] The year aims 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 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 'In Focus' Policy Brief suggests that in many countries the Millennium development goal 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
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