Sanitation in the context of "Slums"

A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agreed definition of the lower boundary for their size. In a narrower sense, a city can be defined as a permanent and densely populated place with administratively defined boundaries whose members work primarily on non-agricultural tasks. Cities generally have extensive systems for housing, transportation, sanitation, utilities, land use, production of goods, and communication. Their density facilitates interaction between people, government organizations, and businesses, sometimes benefiting different parties in the process, such as improving the efficiency of goods and service distribution.

Historically, city dwellers have been a small proportion of humanity overall, but following two centuries of unprecedented and rapid urbanization, more than half of the world population now lives in cities, which has had profound consequences for global sustainability. Present-day cities usually form the core of larger metropolitan areas and urban areas—creating numerous commuters traveling toward city centres for employment, entertainment, and education. However, in a world of intensifying globalization, all cities are to varying degrees also connected globally beyond these regions. This increased influence means that cities also have significant influences on global issues, such as sustainable development, climate change, and global health. Because of these major influences on global issues, the international community has prioritized investment in sustainable cities through Sustainable Development Goal 11. Due to the efficiency of transportation and the smaller land consumption, dense cities hold the potential to have a smaller ecological footprint per inhabitant than more sparsely populated areas. Therefore, compact cities are often referred to as a crucial element in fighting climate change. However, this concentration can also have some significant harmful effects, such as forming urban heat islands, concentrating pollution, and stressing water supplies and other resources.

A slum is a derogatory term for a highly populated urban residential area consisting of densely packed housing units of weak build quality and often associated with poverty. The infrastructure in slums is often deteriorated or incomplete, and they are primarily inhabited by impoverished people.

Although slums are usually located in urban areas, they can be located in suburban areas where housing quality is low and living conditions are poor. Slum residences vary from shanty houses to professionally built dwellings which, because of poor-quality construction or lack of basic maintenance, have deteriorated. While slums differ in size and other characteristics, most lack reliable sanitation services, supply of clean water, reliable electricity, law enforcement, and other basic services. The United Nations defines slums as ".... informal settlements lacking one or more of the following conditions: access to improved water, access to improved sanitation, sufficient living area, housing durability, and security of tenure."

Urban planning (also called city planning or town planning in some contexts) is the process of developing and designing land use and the built environment, including air, water, and the infrastructure passing into and out of urban areas, such as transportation, communications, and distribution networks, and their accessibility. Traditionally, urban planning followed a top-down approach in master planning the physical layout of human settlements. The primary concern was the public welfare, which included considerations of efficiency, sanitation, protection and use of the environment, as well as taking account of effects of the master plans on the social and economic activities. Over time, urban planning has adopted a focus on the social and environmental "bottom lines" that focuses on using planning as a tool to improve the health and well-being of people and maintain sustainability standards. In the early 21st century, urban planning experts such as Jane Jacobs called on urban planners to take resident experiences and needs more into consideration.

Urban planning answers questions about how people will live, work, and play in a given area and thus, guides orderly development in urban, suburban and rural areas. Although predominantly concerned with the planning of settlements and communities, urban planners are also responsible for planning the efficient transportation of goods, resources, people, and waste; the distribution of basic necessities such as water and electricity; a sense of inclusion and opportunity for people of all kinds, culture and needs; economic growth or business development; improving health and conserving areas of natural environmental significance that actively contributes to reduction in CO₂ emissions as well as protecting heritage structures and built environments. Since most urban planning teams consist of highly educated individuals that work for city governments, recent debates focus on how to involve more community members in city planning processes.

Human waste (or human excreta) refers to the waste products of the human digestive system, menses, and human metabolism including urine and feces. As part of a sanitation system that is in place, human waste is collected, transported, treated and disposed of or reused by one method or another, depending on the type of toilet being used, ability by the users to pay for services and other factors. Fecal sludge management is used to deal with fecal matter collected in on-site sanitation systems such as pit latrines and septic tanks.

The sanitation systems in place differ vastly around the world, with many people in developing countries having to resort to open defecation where human waste is deposited in the environment, for lack of other options. Improvements in "water, sanitation and hygiene" (WASH) around the world is a key public health issue within international development and is the focus of Sustainable Development Goal 6.

In medicine, public health, and biology, transmission is the passing of a pathogen causing communicable disease from an infected host individual or group to a particular individual or group, regardless of whether the other individual was previously infected. The term strictly refers to the transmission of microorganisms directly from one individual to another by one or more of the following means:

• airborne transmission – very small dry and wet particles that stay in the air for long periods of time allowing airborne contamination even after the departure of the host. Particle size < 5 μm.
• droplet transmission – small and usually wet particles that stay in the air for a short period of time. Contamination usually occurs in the presence of the host. Particle size > 5 μm.
• direct physical contact – touching an infected individual, including sexual contact
• indirect physical contact – usually by touching a contaminated surface, including soil (fomite)
• fecal–oral transmission – usually from unwashed hands, contaminated food or water sources due to lack of sanitation and hygiene, an important transmission route in pediatrics, veterinary medicine and developing countries.
• via contaminated hypodermic needles or blood products

Transmission can also be indirect, via another organism, either a vector (e.g. a mosquito or fly) or an intermediate host (e.g. tapeworm in pigs can be transmitted to humans who ingest improperly cooked pork). Indirect transmission could involve zoonoses or, more typically, larger pathogens like macroparasites with more complex life cycles. Transmissions can be autochthonous (i.e. between two individuals in the same place) or may involve travel of the microorganism or the affected hosts.

The fecal–oral route (also called the oral–fecal route or orofecal route) describes a particular route of transmission of a disease wherein pathogens in fecal particles pass from one person to the mouth of another person. Main causes of fecal–oral disease transmission include lack of adequate sanitation (leading to open defecation), and poor hygiene practices. If soil or water bodies are polluted with fecal material, humans can be infected with waterborne diseases or soil-transmitted diseases. Fecal contamination of food is another form of fecal-oral transmission. Washing hands properly after changing a baby's diaper or after performing anal hygiene can prevent foodborne illness from spreading..Toilet flushing & subsequent inhaled aerosols is another potential route.

The common factors in the fecal-oral route can be summarized as five Fs: fingers, flies, fields, fluids, and food. Diseases caused by fecal-oral transmission include typhoid, cholera, polio, hepatitis and many other infections, especially ones that cause diarrhea.

Undernutrition in children, occurs when children do not consume enough calories, protein, or micronutrients to maintain good health. It is common globally and may result in both short and long term irreversible adverse health outcomes. Undernutrition is sometimes used synonymously with malnutrition, however, malnutrition could mean both undernutrition or overnutrition (causing childhood obesity). The World Health Organization (WHO) estimates that malnutrition accounts for 54 percent of child mortality worldwide, which is about 1 million children. Another estimate, also by WHO, states that childhood underweight is the cause for about 35% of all deaths of children under the age of five worldwide.

The main causes of malnutrition are often related to poverty: unsafe water, inadequate sanitation or insufficient hygiene, factors related to society, diseases, maternal factors, gender issues as well as other factors.

Cholera (/ˈkɒlərə/) is an infection of the small intestine by some strains of the bacterium Vibrio cholerae. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea lasting a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This can in turn result in sunken eyes, cold or cyanotic skin, decreased skin elasticity, wrinkling of the hands and feet, and, in severe cases, death. Symptoms start two hours to five days after exposure.

Cholera is caused by a number of types of Vibrio cholerae, with some types producing more severe disease than others. It is spread mostly by unsafe water and unsafe food that has been contaminated with human feces containing the bacteria. Undercooked shellfish is a common source. Humans are the only known host for the bacteria. Risk factors for the disease include poor sanitation, insufficient clean drinking water, and poverty. Cholera can be diagnosed by a stool test, or a rapid dipstick test, although the dipstick test is less accurate.

Community-led total sanitation (CLTS) is a participatory approach used primarily in developing countries to improve sanitation and hygiene practices within communities. CLTS aims to achieve behavior change with a "trigger" that leads to spontaneous and long-term abandonment of open defecation practices, thereby improving community sanitation and overall health. The term "triggering" is central to the CLTS process. It refers to methods of igniting community interest in ending open defecation, usually by building simple toilets such as pit latrines. The effect of CLTS is two-fold: actions that increase self-respect and pride in one's community and actions that promote shame and disgust about one's open defecation behaviors. CLTS takes an approach to rural sanitation that works without hardware subsidies by facilitating communities to acknowledge the problem of open defecation, taking collective action to become "open defecation free," and improve sanitation.

The concept was developed around 2000 by Kamal Kar for rural areas in Bangladesh. CLTS became an established approach around 2011. Local governments may reward communities by certifying them with "open defecation free" (ODF) status. The original concept of CLTS purposefully did not include subsidies for toilet installations, as they might hinder the process.