Environmental Health Flashcards
House
Physical structure we live in
Dwelling or physical shelter for living purposes
Healthy house
House that is sited, designed, built, Renovated, and maintained in ways that support the health of its residents
Housing environment
Physical structure used for shelter and it’s environment containing all necessary services , facilities, equipments, and devices required for for health of an individual or a family
Housing tenure
legal conditions under which people live in their dwellings
Room occupancy
Number of persons living in a single room
Household
Individuals who share a single dwelling unit and share common spaces
Why is having a healthy house important ?
Because people spend about 70% of their time in their houses
Tenants living in poor conditions can expose to health hazard like mold, air pollution, pests exposure etc..
Protection of most vulnerable population as they are more fragile ( children, elderly, immune compromised )
Prevent apparition of diseases and injuries so that there’s no high cost for health
Reduce chances of deaths due to home injuries and fires etc.
Types of houses in Ghana
Rooms in compounds Rooms Separate house Flats and apartments Semi detached houses Huts Buildings Tents Improvised housing like
principles of healthy housing
Satisfaction of physiological needs
Protection against infections
Types of physiological needs to satisfy to have a healthy house
Adequate ventilation
Sleep
Lighting
Temperature regulation.
What is considered adequate ventilation
At least 2 windows with one opened to an open space
20% of floor areas should be windows
40% of floor area should be doors and windows
How to ensure good sleep
Separate room
No disturbance and pollution
What is good Lighting
Enough Sun and artificial lights
How to have good Temperature regulation
Should protect from outside weather
How to protect against infections in a house
Safe water supply - protected water source , safe storage and use
Safe human waste management - proper latrines use and presence
Safe solid waste management - waste storage and disposal arrangement
Safe liquid waste management - liquid waste disposal facilities
Good personal hygiene - handwashing facilities
Food safety - hygienic kitchen, proper storage
Vector control - good cleaning, separate animal shed
How to protect against injury in a house
Trip and falls - avoid slippery floor, avoid high or low steps
Collapse of buildings - ensure good structure of roof and walls
Burns - good electrical wire, no improper fuel
Chemical poisoning - good handling and storage of drugs and chemicals
Lack of air breathing - separate kitchen with hood or vents
Electric shock - good installation, no rats to eat wires
How can a house protect against psychological and social stress
Presence of school for children
Presence of water
Presence of places of worship
Presence of places of recreation
Humanitarians assistance and shelter for displaced persons
Diseases associated with substandard housing
Crowding cause PTB , Meningococcal disease, gastroenteritis ,home injury, social tension
Cold indoor causes highBP, Asthma, poor mental health
Poor hygiene causes diarrheal diseases
Factors that affect quality of housing
Poverty Éducation Climate Culture Population mobility
Location guidelines for model housing
Elevated site to prevent flooding
Avoid site of potential natural disaster
Avoid site with unprotected hazard
Site with access to Main Street
Subsoil water at least 3m below
Site away from nuisance, excessive noise breeding sites
Setback definition
Open space around house which allows light and ventilation
Setback guidelines for model housing
Built up area should be 1/3 of overall area in rural and 2/3 in urban
Floor guidelines in model housing
Imperméable
Smooth
Not prone to cracks
Kitchen guidelines for model housing
Separate room
Vented
Impervious floor
Separate storage space for food and provisios’
Latrines guidelines for model housing
Improved facility
Provision for handwashing
Bathrooms and laundry guidelines for model housing
Privacy
Exclusive to the dwelling
Region of Africa where decrease in slums is the most remarkable
West Africa
Slums definition
Dwelling with lack of at least one of these :
Infrastructural integrity
Sufficient living space with no more than 3 persons in a room
Easy access to safe water
Accès to adequate sanitation
Security of tenure with no forced evictions
Benefits of improved housing conditions
Save lives Reduce disease Increased quality of life Reduce poverty Help mitigate climate change Health and sustainable cities
Housing sector percentage in global greenhouse gas emissions
19%
Housing sector percentage in black carbon emissions
1/3
Pollutant types in kitchen
Nitrogen oxides ( respiratory irritants )
Particulate matter, carbon monoxide ( respiratory disorders, lung cancer )
Bathroom indoor air pollution
Mold, Bacteria ( allergies , asthma, respiratory disorders)
Utilities room indoor air pollution
Animal dander from pets ( allergies )
Living room air pollution
Tobacco smoke ( lung cancer )
Furniture chemicals ( respiratory problems )
VOCs , formaldehyde ( mucosal irritant )
Bedroom air pollution
Dust mite
Bed bugs
Pet hais
Insect debris
All cause allergies
Bathroom air pollution
Mildew
Cleaning chemicals
Asthma , exacerbations, cough, wheeze, dyspnoea
The 4Hs determinants of health
Hereditary
habitats
habits
health systems
All the parts scope of environmental health
Ecosystem ecology housing water foods meat hygiene waste solids and liquids pests and vector control
Ecology or ecosystem definition
Community of living things and the environment in which they live
Human ecology defintion
Interaction of humans with the physical environments
Physical environment types
Land water air weather plants animals
Social cultural environment types
Beliefs
practices
norms and values
religion
Challenges of rural environment
Soil depletionn Bush burning continuous cropping Deforestation oil spillage river pollution
Urban environment challenges
No planning in expansion of Cities Noise pollution industrial pollution overcrowding poor refuse and sewage disposal  Indiscriminates location of industries fuel stations
Classes of host
Definitive hosts intermediates hosts paratenic hosts natural hosts accidental host Reservoir host
Definitive host
Harbor parasites while it reproduces sexually
Intermediate host
Harbor parasites during some developmental
Paratenic host
Harbor parasites without showing any developments of parasites
Natural host
Naturally infected with certain species of parasites
Accidental host
Host which is usually not infected with a particular
Reservoir host
Infected animals that make Thursday it’s available for transmission to other hist
Classification of parasites based on location in the host
Ectoparasites (ticks, flies, lice …)
endoparasites (protozoans, worms ..)
Classification of parasites based on level of dependence on the host
Obligates ( Must spend some of the lifecycle in host)
accidental (When parasite attack unusual host)
aberrant (reaches site in hosts where he cannot leave or develop further)
facultative ( I free living normally but kind of thing nutrients from the host)
Types of biological relationships
Symbiosis ( Live in close association)
commensalism ( One organism benefits and the other unaffected)
parasitism ( An organism benefits at the cost of the other)
Mutualism (Both partners benefits)
opportunism (Harm host in state of immune depression)
Some causes of food insecurity
Low technology poor funding noexposure to current knowledge politicization of fertilizer distribution food distribution challenge food storage challenges
Some consequences of food insecurity
malnutrition
weak immune system
morbidity
Factors Contributing in morbidity and mortality in
Communicable disease non-communicable disease STI’s HIV / aids water borne disease avoidable deaths
Factors affecting environmental decay
frustration
poverty
ignorance
cultural beliefs and practices
imbalance between population size and resources
lack of political will to implement environmental laws
Some recommendation to obtain ecological homeostasis
Policies that are formulated by experts, that are people oriented , feasible , backed by political will and legislation , draw from needs assessment
Mass education 
Moderate fertility
migration only when necessary
appropriate hygiene practices
increase in food production
environment friendly and sensitive
sanctions and rewards of application of environmental laws 
attitudinal and behavioral change
preparedness response and recovery of the governments and the citizens
How many deaths can be avoided by making environment healthier
13 million deaths
Proportion of disease burden caused by environmental factors for children below five years
1/3
Developing countries main environmentally- caused disease
Diarrhea
lower respiratory tract infections
malaria
unintentional injuries
Public health definition
Science and art of preventing disease prolonging health through organized effort and informed choices of society organizations public and private communities and individuals
Environment definition
Living in nonliving things that make up our surroundings
Health definition
State of complete physical mental social well-being of an individual and he’s not necessarily the absence of this is
Disease definition
Illness resulting from infection
Infection definition
Entry multiplication and survival of an organism within a host regardless of whether symptoms develop
Hazard definition
Event or situation which has the potential for causing harm to people property or environments
Risk definition
Measure of undesirable events in terms of the likelihood of its occurrence
Sustainable development definition
Developments that meets the needs of the present without compromising ability of future generations to meet their own needs
Environmental health definition
Branch of public health which protects against effects of environmental hazards that can affect health or the ecological balance essential to human health and the environmental quality
Physical hazard
Physical elements from natural or man-made activity which insurance health by damaging effects on sale tissues organs and homeostatic systems or on mental or social well-being
Biological hazards
Biological elements which are from natural or man-made origin which was direct risk to human health through ingestion inhalation inoculation or physical contact
Social hazards
Behaviors associated with human life that are a consequence of settlement in communities and habitation and Influence health and well-being
Psychological hazards
Attitudes and mental processes that have an adverse effects on healthy person or community
Operational skills of environmental health practitioners
Assess consult advise enforce Train / educates advocates evaluates Research report
What are the different landmarks in the evolution of environmental Health
Hunting and gathering age
age of agriculture
colonization of the New World
Industrial revolution
What was the challenge for environmental health in the hunting and gathering age
Humans settled in Africa and Americas and Europe in small groups and relied on hunting specific species of animals which caused some damage to the nature but was limited because the groups of humans were small so small pressure on resources
What event created to switch from hunting and gathering to agriculture
Global population had reached maximum that could be supported by gathering in hunting so it was difficult to get food
What are the Environmental healthchallenges of the age of agriculture
Depletion of nutrients in the land
depletion of water holding capacity
bareness of the soil
animals could not lived anymore in certain places
disruption of nutrient recycling
usage of fertilizers
irrigation techniques which altered content of the soil
What are the Environmentalhealth challenges of colonization each
Settlers used lands for habitation
used animal for food
amount of population went beyond capacity of land
created cities which were against the way of life of natives
brought disease
Environmental health challenges in the industrial revolution
Consumption of raw materials for steam engine and railroads etc.
more wood usage for houses furniture etc.
Expanded markets of wheat corn beef
more productive and efficient agriculture reducing biological diversity
mining activities leading to pollution of the land and water
deforestation
oil discovery leading to pollution
garbage accumulation
consummation of more natural resources
damage to the ecosystem from pesticides
Several environmental issues in the early industrial age
Inadequate water supplies
Unemptied privy vaults
Ill functionning sewers
Unpaved streets littered
stench
noise from horse hooves ,wagon ,wheels ,and railways
regular outbreaks of cholera ,yellow fever
Air pollution water pollution land pollution
What’s Charles Turner thackrah outcry created
The factory act 1833 and mines acts 1842 in UK
Where was occupational health pioneered and by who
In the US by Alice halmiton She documented links between Taxi Gh and exposure and illness in working groups
Who became a pioneer of demography by analyzing the bills of mortality the weekly death records in London
John Graunt
Who showed that Environmental conditions contributed to illness and death
William farr Which led to the passing of the Liverpool sanitary act in 1846
Who pioneered social epidemiology mixed with environmental health
Edwin Chadwick after showing that there is a link between living conditions and health which led to public health act in 1848
Who pioneered the first environmental epidemiological study
Jon Snow for cholera outbreak by observing her proportion of illness among persons we lived near or drink from a Broad Street pump compared to other sources of water
What is the epidemiological triad
Host human
agent
environment
What are the components of the environment
Physical environment
the biological environment
the psycho social environment
Environmental risk factors for disease
Pollution microbes food contaminants weather conditions natural disasters pesticides chemicals Pests,parasites radiation poverty lack of access to healthcare
Are healthy people more productive
Yes
How is life expectancy at birth and economy growth linked
For every 10% increase in life expectancy at birth there’s 0.4% economic growth per
What are the key determinants of health in Africa
Food and nutrition
physical environment
risk factors because of lifestyle
What are the components of the total disease burden in Africa
2/3 communicable disease
1/3 noncommunicable disease, injury
Malaria mortality evolution in Africa
Decreased by 50%
Maternal mortality rate evolution in Africa
Declined by 41%
Under five mortality rate evolution in Africa
Declines from 173 to 95 per thousand
Millennials development goals directly relevant to environmental health
Goal7: ensure environmental sustainability
What are some development gaps in Africa
Access to improve drinking water 64%
access to improved toilets 33%
How many AFRICAN countries were on tract to meet MDG targets
4
According to the Libreville declaration of health what are some major challenges in Africa
Safe drinking water sanitation and hygiene services water soil and air pollution vector control chemicals and waste management food safety health in the workplace
What are some factors contributing to poor health environments in Africa
Climate change
unplanned urbanization
Uncontrolled rapid population growth
urban migration
What are the consequences to public systems of poor environment
Pressure on health systems due to illnesses and cancers
pressure on public utilities due to increased population and unplanned settlements
pressure on public authorities to maintain environmental sanitation education and prevention
What are some consequences of poor environments to human health
Physical ( aesthetics ;odors, noise)
biological (microbial burden , rodents, pest, illnesses, cancers)
social (stigma of minority groups ,conflict ,antisocial behavior
psychological (depression and anxiety)
Is it better to have water sources located upstream of human activity to limit contamination ?
Yes
How much does a person should drink per day
2L per day
How much water does a human consume per day (personal hydiene, cleaning …)
20L per days
Basic requirement for water source
Water collection should not exceed 1km or take more than 30mins for reasonable supply
3 types of water sources
Rainwater
Surface water (lake,s rivers, streams, ponds)
Groundwater (springs, wells, boreholes)
Types of Improved water sources
Piped water on premises
Public stand pipe Borehole, tubewells Protected dug wells Protected springs Rain water collection
Types of unimproved water sources
Unprotceted wells and springs Vendors of water Tanker trucks Cart with small tank Surface water (river, dam, lake, pond, stream) Bottled water
When is bottled water an improved source of water
When bottled water + handwashing and cooking from also improved source
Ghana proportion of access to improved water source hen bottled water included
9/10
Ghana proportion of households that have access to imporved source of water when bottled water not considered
6/10
Availability of water in premises in fhana from 2008 to 2014
23% to 15%
Percentage of Access to sources within 30 mins from 2008 to 2014
51 to 71%
Access to improved water source in urban area
97%
Access to improved water source in rural areas
81%
Does surface water requires treatment before consumption
Yes
Type of chemicals found in groundwater
Arsenic
Fluoride
Nitrates
What is a spring
Permeable layer of underground rock and impermeable layer of underground rocks meet ground surface
How do you protect a spring
No human or animal activity around
Fence around source
Diversion of water coming from rain by drain away from spring
3 types of wells
Shallow wells
Deep well
Artesian well
Characteristics of shalllow well
Situated in aquifer, above firs impermeable layer of rock ‘Less than 10m deep Hand dug Easily contaminated May be Dry in hot season
Charcateristics of deep well
Situated in aquifer, below at least one impermeable layer of rock
Machine dug
Pure water
Water all year round
Chharcateristics of artesian well
Water that flows under natural pressure
Aquifer between impervious layers of rock
Average size of hands dug wells
Diameter about 90 to 180 cm
Depth about 4.5 to 10.5 m
Average size of a borehole well
I Diameter about 5 to 75 cm
Depth 7.5 to 18 m
Why is there a casing of concrete in the borehole well
To prevent collapse of surrounding soil and rock
Driven well characteristics and size
Has metal pipe with a screen attached to the lower end
Diameter from 2.5 to 5 cm and less than 15 meters deep
Dimensions for jetted Wells
Diameter 5 to 30 cm
30m depth
How can we protect water sources
Avoid discharge of waste above water supply
avoid installing intakes below waste discharge
diversion of local storm water flows
enclosure of the water source from animals
control of human activities within boundaries
promote community awareness of impacts of human activity on water quality
What are the characteristics of a sanitary well
Distance of at least 15 m from source of contaminants( recommended 30 to 50 m )
pipe casing in boreholes wells
cement lining with depth of at least 3 m in the wells with wide diameter
lining of well should extends upwards up to 60 to 90 cm above ground level
installation of parapet for at least 70 to 75 cm above ground level
No stagnant water within 2 m of the hand pump
cover for the well
cement concrete platform that extends 1 m around the well
cement concrete platform should slope towards a drain leading away from the well
platform should not be cracked
installation of abstraction pump
fence around well to keep out animals
What are some ways Springs water stores are protected
Intake and overflow pipes screened
fence around surroundings
diversion ditches
sloped cover
sloped apron
inspection hole
tightly covered and secured with a lock
disinfection of water after construction or repairs with chlorine solution
What can contaminate rainwater
Bird droppings leaves dust dirt paints on the roof or roofing materials roof and gutters
What are some ways to protect rainwater
Cleaning of roof and gutters
first flush diversion to allow rainwater to drain away from storage points
mesh screen between roof gutters and the supply pipe leading to storage tank
intact and cleaned mesh screen
no crack on storage tank
water collection area should have adequate drain that is away from the storage tank
no source of contamination around the tank
Which type of water source is preferred
Ground water because of low levels of microbial contamination
When is water safe for consumption
Free from Pathogens
free from harmful chemicals
pleasant to taste
usable for the domestic purposes
How does water appear when there is ferrous iron
Brown discoloration which promotes growth of iron bacteria
How does water appear when there is manganese
Black deposits and pipes stain sanitary wear
When does water smell like rotten egg
When there is hydrogen sulfide when oxygen is depleted
What does it mean when there is a change in taste of water
Deficiencies in water treatment or changes in quality of the raw water source
What does turbidity of the water matter and what level should it not exceed
Because it can interfere with disinfection and microbiological determination should not exceed 5nephelometric units
Consequences of hardness of water
Scale deposition in distribution pipes
excessive soap consumption
scum formation
What does a pH level less than seven cause for water
Enhance corrosion in distribution pipes and raise levels of lead
What does a pH level more than seven means for water
Decreases efficiency of chlorination doing water treatment
Most common source of pathogens in water
Feces
What is used for fecal contamination
Total coliforms
fecal coliforms
E. coli
What is total coliforms
It’s test for all bacteria found in human and animal feces ,found in soil and other natural environments
Z What is fecal coliform test
Subset of total coliform sounds in fishes include some species that may not be a fecal origin
What is e coli test
Only found in feces of human and warm blooded animals
so if it’s there it means that there’s physical condition and possible presence of intestinal pathogens
Should you detect at least a small amount of E. coli and total coliform bacteria in 100 mL sample of water
No nothing
What is the source of nitrates and nitrates poisoning of water and what health problems can it cause
Due to application of fertilizers , seepage of waste water into surface and groundwater
Can cause methaemoglobinaemia can cause cyanosis in young children
Source of fluoride in the water and health problems related
Earth ,manufacture use of phosphate fertilizers, aluminum production
Can cause mottling of children teeths, skeletal fluorosis, crippling ,dental caries
Source of arsenic in water and health problems related
Dissolution from minerals and ores, industrial effluents
Carcinogen (cancer of the skin lungs liver bladder)
darkening of the skin
warts on extremities and torso
decreased production of blood cells
Mercury origin in water and health related problems
Industrial effluent
Inorganic mercury impairs renal function
Methyl mercury effect Central nervous system
Cadmium source in water and health related problems
Galvanized pipes ,metal fittings mindustrial effluents, batteries
Damages kidney
Cyanide stores in water and health problems related
Industrial effluent, inadequately processed cassava
affect thyroid and nervous system
Lead source in water and health related problems
Plumbing system soil things
Neurotoxic
neurobehavioral deficits
calcium metabolism interaction
What is pollution
Introduction into the natural environments of substances that can cause harm to human or animal health plants and other aspects of the ecosystem
Is point source pollution easy to control
Yes
Is nonpoint source pollution easy to control
No because origin difficultly known
What are some different types of water pollutants
Suspended solids and sediments nutrients biological pollutants chemical pollutants pharmaceuticals municipal waste water Leachates agricultural waste
What are suspended solids and sediments water pollutants
Fine particles of inorganic material which are responsible for brown color of weavers during rains
What are the biological pollutants
Bacteria (S. Typhi, v.cholera)
Viruses ( rotavirus, poliovirus, hepatitis A)
Protozoa ( cryptosporidium, giardia )
Helminths ( guineaworm, schistosoma)
Types of chemical pollutants
Heavy metals
Pesticides, herbicides, insecticides, fungicides (malathion, parathion, delthametrine)
What is eutrophication
Nutrients are discharged in large quantities into water bodies
What is algal bloom
Excessive and sudden increase of microscopic algae in water
Why is there dead zone in water source
Algae die and when they decay by bacteria this dissolves dissolved oxygen level
Consequences of pharmaceuticals in water source
Endocrine function of aquatic animals disrupted
How do humans get exposed to contaminated water source
Drinking Cooking Washing Bathing Recreation
People at risk to water contamination
Infants young children
People living in unsanitary conditions
Debilitated persons
Elderly
Types of water pollution based on disease transmission route
Water borne route (pathogen ingested by feco oral route)
Water washed diseases (person to person condition, due to hygienic conditions)
Water based disease (transmission by aquatic intervertebrate host, helminths)
Water related disease ( insect vectors breeds in or near water)
Contro strategies of water borne diseases
Improve water quality
Hygiene
Education
Waterwashed diseases control ( scabies, trachoma)
Improve water quantity , availability, access
Hygiene education
Water based diseases control (schistosomiasis , guinea worm )
Decrease contact with contaminated water
Public education
Improve domestic plumbing
Dry flood damaged homes
Water related diseases control ( dengue, malaria, trypanosomiasis , onchocerciasis
Larvicide Biological control Decrease passage through breeding sites Insecticides Improve stormwater drainage Public education
Houselhod treatment of water
Boiling water
Filtration and chlorination by using bleach
Solar disinfection by exposition to sunlight for 6h
Sterilizing tablets to put into water
Filter with pore of 1micron for protozoa removal
Municipal and industrial water treatment
Coagulation (merging of suspendable material, colloidal material and bacteria when adding aluminum sulphate)
Flocculation ( mixing and inter particle contact)
Filtration (removal of fine particles )
Sediment(bacteria and particulates settle at bottom)
Disinfection (chlorine ti destroy microorganism)
Adsorption (carbon removes taste , odors,, organic chemicals )
Ion xchange (ions removal)
Distillation (evaportation and condensation to desalinate)
Gas exchange (removal of dissolved gases, iron , manganese etc)
Uv radiation (remoal of tate and odors)
Reverse osmosis (removes total dissolved solids, hardness
Control measure at distribution system of water
Fully enclosed of distribution systems Storage tank secured with external drainage Backflow prevention devices Positive pressure maintenance Adequate residual desinfection Efficient maintenance Law enforcement
What is waste water
Combination of domestic effluent , water from commercial establishments in institution , industrial effluent , stormwater , urban run off,
agricultural horticultural aquacultural effluent
What is sewage
Liquids or wet waste with excreta , effluents from household waste ,water rain in industrial sources
What is soulage
Storm water and household waste water Devoid of excreta
Sewers
Pipes through which sewage flows
What’ is black water
Water water from toilets with excrements
Black water amount produced per year per person
10000 to 25000
Grey water definition
waste water from bath and kitchen devoid of excrement
Amount of grey water produced per day per person
100,000
Is urine sterile in individuals
Yes
Domestic Nutrients in urines
Nitrogen
Phosphorus
Potassium
What is the amount of urine excreted annually per person
500L
Amount of fecal matter excreted annually per person
50kg
What is the main source of pathogens and microbes
Feces
What is sanitation
Provision of services and facilities for safe collection ,disposal ,and reuse of human excreta and other liquid watse
What is safe disposal
Excreta is contained, treated so that doesn’t affect human health
What procedures composed environmental sanitation
Excreta disposal and management
Solid waste management
Drainage
Hygiene practices
What is the goal of environmental sanitation
Prevent diseases by hindering pathogens associated with excreta and waste water that come into contact with people
When can you say that sanitation and waste water system are sustainable
Economically affordable Technically appropriate Socially acceptable Protects environments Protect natural resources
What is the biochemical oxygen demand
Amount of oxygen required Over 5 days at 20degrees to oxidize organic constituents of sewage
What is the importance of biochemical oxygen demand
Measures amount of organic contamination in waste water
If high then very contaminated
Does decomposition of organic waste increases or decreases amount of available oxygen
Decreases
Raw sewage BOD
300-400 mgL
BOD of slaughterhouse waste water
2000
What is the chemical oxygen demand
Amount of oxygen required to oxidize organic and inorganic solids
Which one is higher , BOD or COD
COD
Broad category of latrines
On site
Off sites
What is on site latrines
Containment and treatment at the toilet location
Examples of on site latrine
Simple pit latrine Ventilated improved pit latrine VIP Kumasi ventilated improved pit latrines Ecological sanitation toilet Bio digester system
What is off site latrines
Based on sewerage systems which requires water supply and provision of treatment systems for waste water
Where do you find off site latrines
Advanced countries
Areas of high population
Example of off site latrine
Water closer connected to sewerage systems
What is a non water carriage system
Dry sanitation system which remove pathogenic germ in latrine content to make them hygienically safe without destroying nutrient
What is water carriage system
A wet sanitation system which uses water to push content into an on site treatment option
What are examples of non water carriage latrine s
Cartage , bucket latrine San plat , pit latrine Ventilated improved pit latrine VIP KUMASI VENTILATED improved pit latrine Composting latrine
Examples of water carriage latrines
Hanging latrines
Aqua privy
Flush toilets
What is an improved sanitation fac8kity
Hygenically seperates human excreta from human contact
Components of improved sanitation facility
Flush toilet Pour flush toilet Urine diversion dehydrating latrine VIP KVIP pit latrine with slab Composting toilet
Components of unimproved sanitation facility
Flush or pour toilet that does not go to piped sewer system, septic tank, pit latrine
Pit latrine without slab Open pit Bucket latrine Elevated latrine Hanging latrine Shared facilities of any type No facilities
What are the characteristics of a sanitary latrine
No handling of fresh excreta
No contamination of the ground or surface water
No contamination of soil
no accès to vectors or vehicles of transmission
No nuisance due to odors or poor aesthetics
Benefits of latrines use
Dignity due to Privacy Safety Clean environment Reduced malodor Improved hygiene Resource and energy recovery Transmission cycle of disease broken
Pit latrine characteristic s
Rectangular pit
1-1.5 m in diameter or square
3-4m deep
Lined with Pottery rings, blocks, stones, or woods,
Cement , mortar or brick reinforcement
Base Of superstructure elevated 15cm above ground to prevent flooding
Minimum of 2m from groundwater table
6m away from dwellings
30-50m away and downstream from water source
Why is concentre used in squatting slab pit latrine
Support strength
Ease cleaning and washing
Should you close the squat hole of pit latrine when not in use
Yes
Why is the superstructure of pit latrine dark
To discourage flies
When is pit latrine not used anymore
Used till full , sealed and left to decompose for 2 years
What characteristics do ventilated improved pit latrine have that differentiates them form the regular one
Vent pipe 1 m above roof of superstructure
Vent pipe with minimum of 100m
Fly screen in vent pipe to overcome odor and flies
Convection current should bring back cold air inside the pit
Is air in the pit warmer of colde than the outside due to the environment
Warmer
Mechanism of action of pit latrine
Feces broken down by bacteria and soil organism
Anaerobic digestion decompose it
Hot air from decomposition drawn from pit
Fresh air gets into pit by vent pipe
Number of person supported by pit latrine
20-50
Time of duration of pit latrine
20 years
When is a pit considered full
If sludge over 0.5 of slab
Compost toilet characteristics
Aerobic bacterial action on feces
Can have solar power
Minimal water requirements
Can be built on site or pre fabricated
What is composting
Anaerobic decomposition of organic matter by microoorganism and worms which produces co2 , water, heat and hummus
Should you totally empty compost latrine
No to maintain organisms required for decomposition
3 phases of composting processes
Mesophile - ( few days , 20-40 degrees)
Thermophile - (40-70 degrees days to months )
Cooling - over several months
Characteristics of flush toilets
Under water seal u shaped
Maintained water level
1 bucket per day to make up for losses evaporation
Anaerobic digestion in septic tank
Do you need to de sludges septic tank periodically
Yes
What is the purpose of treating waste water
Produce disposable effluent which is harmless and prevent pollution of the environment
Remove contaminant
What is the by product of treating waste water
Effluent and sludge
Percentage of waste water that receives adequate treatment worldwide
Repartition around the world
20 percent globally
70% in advanced countries
8% in low income countries
Types of contaminant in waste water
Plant nutrients - nitrogen, phosphorus , potassium
Pathogens - viruses, bacteria , Protozoa , helminthique
Heavy metals - cadmium , chromium, copper, mercury , nickel , lead, zinc
Organic pollutants - polyaromatic hydrocarbons , biodegradable organic
Micro pollutants - pharmaceuticals, personal care products, cleaning agents
What does 1 gram of feces contains
10,000 viruses
1,000,000 bacteria
1000 parasites cysts
100 parasitic eggs
Examples of on site treatment of sewage
Septic tanks
Bio digesters
Example of off site treatment of sewage
Waste stabilization ponds
Central sewage treatment plant via sewers
Examples of waste water collection system
On site system Centralized system Combined on site and centralized system Semi centralized system Decentralized system
Characteristics of centralized system
Collection and removal of urban waste water
Linked to treatment plant where waste water and sludge are treated and disposed under controlled conditions
Characteristics of on site and semi centralized systems
Collection, treatment , and disposal or reuse of waste water from small communities
Many small sanitation
Waste water treatment facilities designed and built locally
Decentralized system characteristics
Maintain solid and liquid fractions of waste water near origin
minimize collection network
Septic tank characteristics
Water tight chamber which receives black water form toilets and grey water
Sedimentation and anaerobic digestion by bacteria work on solids
Sludge dug out periodically
Soak pit characteristics
Porous walled chamber allows water to slowly soak in ground
Filled with coarse rocks and gravel for support
What is a constructed wet land
Natural systems in which waste water flows through
Made of sand or gravel
Physical and biological treatment
Sewage treatment steps
Primary treatment
Secondary treatment t
Tertiary treatment t
What is sewage pre treatment
Screening to remove large objects
Grit removal to remove sand, grit, stones, broken glass
Fat and grease removal
Primary treatment of sewage
Clarifiers help with sedimentation of sludge
Oil and grease removed
Saponification
Removes 60-65% of suspended solids
Secondary treatment of sewage
Degradation of biological content
Aerobic process
Secondary treatment of sewage
Fixed film
Suspended growth system
Zoogleal layer with algae , fungi, Protozoa which oxidizes effluent
Oxidation and nitrification to form coagulative mass
Secondary settling tank of heavy mass
Anaerobic auto digestion causes Sludge to Broke down into
Methane
Co2
Ammonia
End product of secondary treatment
Effluent with low levels of organic material and suspended matter
Tertiary treatment
upgrade quality of water before it foes to environment Filtration Lagooning Engineered reedbeds Nutrient removal Disinfection
Filtration in tertiary treatment
Sand removes residual suspended matter
Activated carbon to remove residual toxin
Lagooning n tertiary treatment
Aerobic environment and reed removes fine particulates
Engineered removal in tertiary treatment
Provides aerobic environment
Nutrient removal in tertiary treatment
Nitrogen and phosphorous removal
Désinfection in tertiary treatment
Ozone , chlorine, up radiation, and sodium hypochlorite to reduce microorganism in water
Waste stabilization ponds
Man made water bodies created for low cost treatment of black water. Grey water and fecal sludge
Where do you find stabilization ponds
In rural areas
3 types of stabilization. Ponds
Anaerobic
Facultative
Aerobic
Stabilization ponds characteristics
Nitrogen and phosphorus in effluent
Minimum permeability of grounds
Lining of clay, asphalt, compacted earth if permeable
Fencing area to provide protection animals
Hot li
Advantages of stabilization ponds
Low investment Ow operation cost Minimal technique equipment Long life span High resource recovery
Disadvantage of stabilization ponds
Form reservoirs for breeding vectors
