Public Health in Emergencies and Disaster: Water, Sanitation and Hygiene (WASH)

Public Health in Emergencies and Disaster, Water, Sanitation and Hygiene (WASH)

Learning Objectives:

• Show awareness of the public health significance of WASH in emergencies
• Identify the causes and route of transmission and spread of WASH related diseases
• Identify prevention strategies in the spread of diseases
• Identify strategies to promote a safe environment during disaster/calamities and emergencies

Common Sanitation-Related Problems During Emergencies

• During emergency situations, prompt and efficient environmental sanitation measures must be undertaken to prevent or minimize health hazards.
• Health protection cannot be effective without the creation of a healthful environment.
• A primary concern in disaster management is the provision of:
  • emergency sanitation facilities
  • services to prevent and control occurrence of sanitation related diseases.
• Disruption and crowding together of people accustomed to living in different less crowded conditions makes adequate sanitation of critical importance
• Facilities to which the evacuees were accustomed are no longer available
• Basic services are often lacking
• Habits may have to be changed
• Indiscriminate disposal of human waste and other waste pose serious threats to the health of individuals, family groups and the community
• General sanitation activities for the protection of the people are interrupted and alternative measures may differ from those of normal periods
• Provision of safe water
• Proper disposal of human excreta
• Disposal of wastewater and solid waste
• Proliferation of insect and rodents
• Personal hygiene and safe food handling practices

Flow of Presentation

• Introduction
• Principles of environmental health related to emergencies
• Effects of disasters on environmental health facilities
• Importance of hygiene promotion, water supply and sanitation
• Standards and indicators on excreta disposal
• Solid waste management, wastewater, drainage
• Summary

Emergencies and Disasters

• Can occur anywhere in the world
• May be predictable to a certain extent, or unpredictable in many incidents
• Can specifically affect individual human health
• Can impact people’s lives, the communities and the infrastructure built to support them

Principles of Environmental Health Related to Emergencies

• Environmental health problems: physical, biological, social environment
• Impact human health, well-being and survival:
  • shelter
  • water
  • sanitation
  • disease vectors
  • pollution, etc.

Effects of Disasters on Environmental Health Facilities

• Most commonly affected:
  • Water supply
  • Solid waste handling
  • Food handling
  • Vector control
  • Home sanitation

Water Supply

• Damage to civil engineering structure
• Lack of drinking water
• Contamination: microbiological, physical or chemical

Water-Related Diseases

• Waterborne diseases:
  • Caused by the ingestion of water contaminated by human or animal feces or urine containing pathogenic bacteria or viruses
  • Include cholera, typhoid, amoebic and bacillary dysentery and other diarrheal diseases
• Water-vector borne diseases:
  • are diseases transmitted by insects harboring and propagating in water
  • Include dengue, filariasis, malaria, yellow fever, chikungunya, zika virus
• Water-washed diseases:
  • Due to lack of water and poor personal hygiene
  • Include scabies, trachoma and flea, lice and tick- borne diseases
• Water-based diseases:
  • infectious diseases transmitted through an aquatic invertebrate organism
  • include Schistosomiasis, Leptospirosis

Solid Waste Handling

• Damage to civil engineering structure
• Collection and transportation failures
• Equipment shortages
• Personnel shortages
• Water and soil pollution

Food Handling

• Shortage of food
• Spoilage of stored/refrigerated foods
• Damage to food preparation facilities
• Transportation failures
• Power outages
• Flooding of facilities
• Contamination

Vector and Pest Control

• Proliferation of vector breeding sites
• Increase in human/vector contacts
• Disruption of vector-borne disease control program
• Examples of common vectors and the corresponding diseases:
  • Anopheles mosquitoes - malaria
  • Aedes mosquitoes – dengue fever
  • Lice – epidemic typhus
• Insects and other arthropods can constitute a major nuisance in disasters

Vectors and diseases likely to be present in emergency settlements:

• Reference: Environmental Health in Emergencies and Disasters: A Practical Guide (WHO)

Home Sanitation

• Destruction of structures
• Contamination of water and food
• Disruption of power, heating fuel, water supply and waste disposal services
• Overcrowding

Importance of Hygiene Promotion, Water Supply and Sanitation

WASH in Emergencies

• It consists of strategies, intervention and concerns related to water supply, sanitation, vector control, waste management and hygiene promotion to minimize morbidities, mortalities, and disabilities in times of emergencies and disasters
• The goal of WASH is to promote good personal hygiene in order to protect health, improve health conditions, promote dignity of living or enhance the quality of life, and protect the environment.
• Hygiene Promotion is the planned, systematic attempt to enable people to take action to prevent or mitigate water, sanitation and hygiene related diseases

Aspects to Consider in Hygiene Promotion

• Shared responsibility
• Needs assessment
• Targeting priority hygiene risks and behaviors
• Reaching out all to sectors of the population
• Managing facilities

Public Health Promotion

• Public Health Promoters (PHP) focus on helping communities to prevent diseases related to WASH.
  1. Distribution of hygiene kits and water kits
  2. Communication and information dissemination on things like:
     • Importance of hand washing, how to keep water clean
     • how to dispose of human waste
  3. Training on use and maintenance of latrines
  4. Vector control and malaria prevention activities
     • Fly and mosquito control chemical sprays;
     • Campaign to clean up after animal waste
     • Destruction of mosquito breeding grounds and ponds
     • Mosquito net distribution

Innovative approach to public health promotion

• Communicating in different ways to influence behaviour change
  • Radio and songs
  • Street theatre
  • Puppet shows
  • Interactive text messaging
• Development of interactive e-learning module on information, education and communication (IEC) in WASH emergencies

Public Health Significance

• In most emergencies, provision of a safe and adequate water supply is the most urgent need of the community.
• Occurrence of waterborne and foodborne diseases is usually associated with the absence of lack of potable and safe water.
• In emergencies water is often not available in adequate quantity and quality, thus creating a major health hazard.

Water Supply

• Mobilize resources to ensure access to adequate and safe water through water quality surveillance, disinfection/ treatment, provision of storage facility, development and protection of water supply sources
• Ensure operation and maintenance of water supply facilities including provision of spare parts

Water Quantity (how much is enough?)

• The minimum amount of water needed to survive is 3-5 liters/person/day.
• Reduction in the quantity of water available to individuals directly affects their health.
• As supplies are reduced, clothes can not be washed, personal hygiene suffers, cooking utensils cannot be properly cleaned, food can not be adequately prepared and finally the direct intake becomes insufficient to replace moisture lost from the body.
• Average water used for drinking, cooking and personal hygiene in any household : at least 15 liters per person per day
• Maximum distance from any household to the nearest water point : 500 meters
• Queuing time at a water source : no more than 15 minutes
• Reduction is reflected in increased incidence of parasites, fungal and other skin diseases, eye infections, diarrheal diseases and the often fatal dehydration associated with them.
• Even those individuals who may have traditionally lived on less than the normally recommended amount of water (e.g. indigenous people) will require more in an evacuation camp because of crowding and other environmental factors.

Water Quality (what is safe water?)

• A large quantity of reasonably safe water is preferable to a small amount of very pure water because quantity is more important than quality.
• The most serious threat to the safety of water is the contamination by feces. Coliforms themselves don’t necessarily transmit diseases, but are indicators of fecal contamination. As such they serve as marker for other pathogens.
• The basic and essential requirement for the first day at the evacuation center is the available water sources protected from pollution. Natural sources such as rivers are more easily polluted of the open contamination.

Water Quality Indicators

• No fecal coliform per 100 ml at the point of delivery
• For piped water supplies, water is treated with a disinfectant – free chlorine residual : $0.2 – 0.5 mg/l$
• No objectionable taste
• No objectionable odor
• turbidity : below 5 Nephelometric Turbidity Unit (NTU)

Physical and Chemical Contamination

• Risk should be assessed rapidly by carrying out physical and chemical analysis

Water Use Facilities Indicators

• Each household: at least 2 water collecting containers of 10-20 liters, plus enough clean storage containers to ensure there is always water in the household
• Personal hygiene : at least 250g of soap per person per month

Emergency Disinfection of Drinking Water System

• Top priority should be given to putting the water system back into operation
• Water pressure should be raised and the chlorine concentrations should be increased
• Repaired distribution systems should be flushed and disinfected with a $50 mg/l$ chlorine solution for a contact period of 24 hours.
• Samples should be taken for microbacteriological examinations

Emergency Disinfection of Drinking Water Sources

• Deep/shallow wells and springs should be disinfected with $50 – 100 ppm$ chlorine solution with a contact period of 12 hours
• Municipal water system should immediately put back into operation and should be disinfected with $50 ppm$ chlorine solution with a contact period of 24 hours
• Springs and wells near the disaster area may be used, but water will have to be treated, depending on the quality of the source

During emergencies and disasters, DISINFECTION, STORAGE, EFFICIENT DISTRIBUTION OF DRINKING WATER SUPPLY SHOULD BE ENSURED.

Water Disinfection and Treatment

A. Boiling

• boiling for at least 3 minutes

B. Chemical Disinfection

• Prepare stock solution of 60-70% available chlorine by dissolving thoroughly
  • One (1) level teaspoon of calcium hypochlorite (powder/granular form) to one (1) liter of water in a dark colored bottle. Keep the bottle out of direct sunlight
    • NOTE: The solution is good only for seven (7) days)
• Chlorination of drinking water
  • From the stock solution, get two (2) teaspoonful and mix with twenty (20) liters (approximately 5 gallons)
  • Stand disinfected water for at least 30 minutes before drinking

Other chemical disinfection method

• Includes using:
  • HYPOCHLOR
  • WATERINE
  • Puritab
  • AQUATABS

Water disinfection by 1.25% Sodium Hypochlorite Using Hyposol

• Step 1: Tupiin sa apat ang malinis na tela (o T-shirt na puti) at gamitin itong pansala ng tubig.
• Step 2: Punuin ng tubig ang 20-liter o 5-gallon container (o jerry can).
• Step 3: Tanggalin ang transparent plastic cap at buksan ang puting cap ng HypoSol.
• Step 4: Gamitin ang transparent plastic cap na panukat. Lagyan ito at sukatin dito ang HypoSol hanggang $3.5ml$ na guhit.
• Step 5: Isalin sa container na may 5-galon na tubig ang $3.5ml$ na HypoSol.
• Step 6: Takpan ang container at alugin ito upang humalo ang HypoSol sa laman nitong tubig. Hayaang may takip ang container sa loob ng 30 minuto o mahigit.
• Step 7: Makaraan ang 30 minuto, buksan ang takip ng container. Hayaang bahagyang nakabukas ito sa loob ng 10minuto o mahigit. Ito ay upang sumingaw ang tubig. Tiyaking di mapapasok ng anumang dumi o insekto ang tubig sa container.
• Step 8: Makaraan ang 10 minuto o mahigit, takpang muli ang container. Ang tubig na nilagyan ng HypoSol ay ligtas nang inumin.

Disinfection of Water Tanks (Mobile/ Static Tanks) and Reservoirs Used for Drinking Purposes

• Cleaning the tank
  • Drain, scrub the walls and bottom of the tank
  • Rinse/ flush the walls and bottom using clean water
• Chlorine treatment for the tank
  • Fill the tank with water up to ¼ level
  • Prepare the chlorine solution
• Weight of Calcium Hypochlorite (chlorine granules) in gms. = Volume of tank (cu m)) x dosage (mg/l) / Percent of available chlorine
• Dissolve slowly the computed weight of Calcium Hypochlorite on a pail of water
• Pour the solution slowly into the tank
• Fill-up the tank with water to full capacity
• Stand for 24 hours
  • Note : To shorten the contact time to 8 hours, increase the Chlorine dosage to$100 mg/l$
• Drain the tank
• If the tank is connected to the piping system, flush it through the pipelines to disinfect the pipes
• All faucets must be open during flushing

NOTE: Water used for disinfection process is not safe for domestic use

The Water Supply Tankering Option

• Often used in the initial emergency purposes
• Water trucking is a method of transporting water from water sources to bladders or tanks set near tap posts or distribution points.
• In this system, water from the source is placed in a clean water tank truck and physically transported located far from the source.
• Avoid having it on routine basis unless absolutely necessary: use it only while permanent systems are being put in place

Water Tanks

• A large storage tank of water that drains in the outlet just few meters from where it stands.
• A good water source is supplied by one international agency

Water Bladder

• Water bladders are a type of water tank made of rubber, PVC and other synthetic materials, which are normally foldable.
• This is a storage container that maintains the water needs of the evacuess..
• To fill the bladder, methods like water trucking supported by borehole or hand dug wells or other water sources are used.
• Any disinfection needed can be done in the bladder itself.
• The bladder tank comes in ranges of sizes, 2000, 4000, 5000, 10,000 and 20,000 litres. $5,000$ and $10, 000$ are most common variations.

Standards and Indicators on Excreta Disposal

Aims of safe excreta disposal program

• Dig the very first day
• Ensure environment free from contamination by human feces
• Isolating parts of the system that works (re-routing of pipes)
• Installing emergency toilets/portable toilets
• Use of septic tanks and containment tanks that can be desludged

Planning Guidelines for Minimum Numbers of Toilets in Disaster Situations

ACCESS TO, AND NUMBER OF TOILETS

• Communal trench latrine- 1 for 50 persons
• Pit latrine, ventilated improved pit latrine, etc - 1 toilet per 20 people
• Must be maintained and kept clean
• Separate toilet for men and women
• Toilets should be located at not more than 50 meters away from the dwellings

Design, Construction and Use of Toilets

• Acceptable facilities
• Depend on the following factors:
  • Preferences and cultural habits of the intended users
  • Existing infrastructure
  • Ready availability of water
  • Ground condition
  • Construction materials
• Design of toilet:
  • Can be used by any section of the population
  • Situated in a way to minimize threats to users
  • Easy to keep clean
  • Provide a degree of privacy
  • Minimize breeding areas for flies, mosquitoes

Safe facilities

• Ensure that women feel safe
• Communal toilets provided with lighting or families provided with torch

Distance from water sources:

• For pit latrines and soak-away
  • $30$ meters away from any groundwater source
  • Bottom of any latrine at least $1.5$ meters above the water table
• In flooded or high water table environments
  • build elevated toilets and septic tanks to contain the excreta and prevent contaminating the environment

Excreta Disposal

• Where municipal systems are disrupted/inadequate:
  • Immediately establish temporary, alternative rearrangements – probably communal trench latrines, and/or chemical toilets
  • Disinfect the immediate environment of any damaged facilities
  • Repair/replace facilities as quickly as possible

Emergency Sanitation

• Consider that in an emergency: large number of people may be on a site with limited or no services available
• Going to the bush is not an option.
• Immediate sanitation options:
  • Shallow low trench latrine
  • Communal latrines
  • Family latrines
  • Urine diversion toilet

Shallow/Deep Trench Latrine

• Intended for short period up to 1 week
• Soil from the digging of the trench should be pilled at the side and users throw/shovel a little in each time to cover their excreta

Communal Latrine

• An intermediate step between emergency sanitation and the ideal of the family latrine
• Still needed for evacuation centers, market and schools even where family latrines are provided

Other sanitation technology option

• ECOSAN TOILET

Other Facilities to Consider

• In addition to latrines:
  • Bathing/washing area for evacuess
  • laundry areas for washing clothes
  • hygienic areas for slaughtering animals

Hand Washing Facilities

• Provide means for the users to wash their hands after defecation
• Set up hand washing stations complete with soap at all latrines and communal facilities

Vector Control Program

• Insects and rodents are vectors that cause diseases:
  • Mosquitoes: dengue hemorrhagic fever, malaria
  • Flies: diarrheal diseases due to viral and bacterial causes
  • Biting flies: painful nuisance
  • Fleas: plague
  • Ticks: relapsing fever
  • Human body lice: typhus & relapsing fever
  • Rats and mice: leptospirosis

Vector Control Objectives

• To reduce human-vector contact.
• To reduce longevity or abundance of disease vectors.
• To reduce vector breeding sites, where and when possible.

What is a Vector?

• A vector is any insect or arthropod, rodent or other animal of public health significance capable of harboring or transmitting the causative agents of human disease (such as dengue and malaria).
• Under certain circumstance insects, arthropods and other animals capable of causing direct human injury or discomfort, but not disease, are sometimes referred to as vectors.

BASIC REQUIREMENTS IN VECTOR CONTROL

• Understand the way of life of the specific vectors:
  • the anatomy
  • the method of growth
  • the time it takes for the vector e.g. for insect to grow from egg to adult
  • habits
  • stage of its life history in which it causes damage
  • its food
  • its common living places

Method of Control

Vector control measures

• Habitat Control
  • Removing or reducing areas where vectors can easily breed can help limit population growth.
  • For example, stagnant water removal, destruction of old tires and cans which serve as mosquito breeding environments and good management of used water can reduce areas of excessive vector incidence.
• Reducing Contact
  • Limiting exposure to insects or animals that are known disease vectors can reduce infection risks significantly.
  • For example, bed nets, window screens on homes, or protective clothing can help reduce the likelihood contact with vectors.
  • To be effective this requires education and promotion of methods among the population to raise the awareness of vector threats.
• Chemical Control
  • Insecticides, larvicides, rodenticides, Lethal ovitraps and repellents can be used to control vectors.
  • For example, larvicides can be used in mosquito breeding zones; insecticides can be applied to house walls or bed nets, and use of personal repellents can reduce incidence of insect bites and thus infection.
• Biological Control
  • The use of natural vector predators, such as bacterial toxins or botanical compounds, can help control vector populations.
  • Using fish that eat mosquito larvae or reducing breeding rates by introducing sterilized male tsetse flies have been shown to control vector populations and reduce infection risks.
• Environmental Management
  • Environmental Management - modify environment to permanently remove vector habitat or periodically manipulate environment that makes it unsuitable for vector feeding, shelter or breeding (e.g. maintaining the cleanliness of immediate premises)
• Educational
  • Provide adequate public information and health education

Solid Waste Management

Impact on environment

• odor problems

• clogging of sewers, drains and waterways

• aesthetic effects

• soil pollution

• contamination of water supply sources

• air pollution

• Waste Minimization

  • Reduction at source
  • Reuse
  • Recycle

• Segregation

  • Color Coding
  • Labeling

• Storage (Use appropriate storage facilities- proper location, security and protection)

Collection and Disposal

Timely Collection is NECESSARY

• SW must be COLLECTED SEPARATELY
• Recommend:
  • Frequency of collection ONCE A DAY
  • Cover total catchment area
  • Suitable lowland for final disposal site
  • Final disposal site to be constructed in a SANITARY and ECOLOGICAL MANNER
  • Compaction and covering daily with soil
  • Community cooperation/participation is vital

Wastewater

• Whenever water is handled, there will be some wastewater
• Every water point must have adequate drainage to avoid becoming a breeding ground for mosquitoes and a means of spreading disease
• Indicators:
  • Storm water drains kept clear
  • Shelter, paths, water and sanitation facilities are not flooded or eroded by water

Blind Drainage

• A satisfactory method of collecting waste water from the kitchen sink.
• This is used in individual households in rural areas without a sewerage system.
• Advantages:
  • It eliminates potential breeding places for mosquitoes and other vectors which maybe carriers of diseases.
  • It also minimizes the possible contamination of ground water supply sources.

Blind Drainage or Soak-away Pit

Drainage

• Indicators:
  • Drainage water do not pollute existing surface or groundwater sources or cause erosion.
  • Sufficient number of appropriate tools are provided for small drainage works and maintenance
• Sullage or domestic wastewater is classified as sewage when mixed w/ human excreta
• On-site disposal
• Drainage from water points and washing areas should be on -site