Transcript Document 7144337

Global Water Sanitation and Health:
What this Course is about
Mark D. Sobsey
University of North Carolina
Department of Environmental Sciences and
Engineering
[email protected]
Kofi Annan
United Nations SecretaryGeneral
“We shall not finally defeat AIDS,
tuberculosis, malaria, or any of the other
infectious diseases that plague the
developing world until we have also won
the battle for safe drinking-water,
sanitation and basic health care.”
Global Burden of Disease Attributable to
Selected Major Risk Factors
Underweight
Unsafe sex
Tobacco
(within region)
Percent of total burden
Overweight
5% -
Water, sanitation and hygiene
(5.5%)
Indoor air (3.7 %)
Zinc deficiency
Tobacco
1% -
Alcohol
Overweight
Ambient air Lead Occupational injuries
Climate change
Developing countries (high mortality)
More recent estimate even higher!
Alcohol
Physical
inactivity
Occupational risks
Unsafe sex
Ambient air Water, sanitation and
hygiene
Lead
Developed countries
Global Burden of Poor Water,
Sanitation and Hygiene (WSH)
• 1.1 billion people (~17% of the population) lack access
to improved water
– tap water in house/yard from public distribution
systems,
– protected wells & springs
– public stand posts
– rain water collection
• 2.6 billion (42% of population) lack access to basic
sanitation
– sewerage, on-site septic waste treatment system, latrine
Global Burden of Poor Water,
Sanitation and Hygiene (WSH)
• 1.8 million people die every year from diarrheal
diseases (including cholera)
• 90% are children under 5
• mostly in developing countries.
• 80% of the population without access to drinkingwater are rural dwellers, but future populations
will be mainly urban
• Peri-urban slums are among the most underserved
and unsanitary places on earth!
The Older Conventional View:
Lack of WSH = Disease and Poverty
• Inadequate water supply
• Time, financial cost
• Unsafe water resources
• Disease burden
• Inequitable access
• Health care costs
POVERTY
The Newer Optimistic View!
WSH = An Engine for Development and Productivity
• Improved water supply
• Time, financial savings
• Safe water resources
• Averted disease costs
• Universal access
• Healthy populations
Development
Millennium Development Goals
•Goal 1 Eradicate extreme poverty and hunger
•Goal 2 Achieve universal primary education
•Goal 3 Promote gender equality and empower women
•Goal 4 Reduce child mortality
•Goal 5 Improve maternal health
•Goal 6 Combat HIV/AIDS, malaria, and other diseases
•Goal 7 Ensure environmental sustainability
• Target 9: Integrate the principles of sustainable development into
country policies … reverse loss of environmental resources.
• Target 10: Halve by 2015 the proportion of people without
sustainable access to safe drinking water and basic sanitation
•Target 11: improve the lives of at least 100 million slum dwellers
•Goal 8 Develop a global partnership for development
What a lot of this course will be about:
The “F”s of WSH
• Feces
• Fingers
• Flies
• Fields/Food
• Fluids
• Fomites
Water Treatment
A Lot of What Else this Course is About
• Air pollution
• Solid waste
management
• Vectors &
vector-borne
diseases
• Disasters and
emergencies
• Climate change
health effects
Human Sanitation:
Fundamental but Often Lacking
• Excreta
management
and disposal
• Hygiene
behaviors
– Handwashing
• Safe water
Sanitation: Our Biggest Failure
• Our sanitation systems
don’t work well and
result in pathogen
release
• Whether community or
on-site, they all fail or
have serious
deficiencies
• Sanitation is one of the
biggest technological
gaps we have globally
• Pathogens go
everywhere as a result
Roman latrine
Latrine
VIP latrine
Inferior/Absent Community Wastewater
Treatment Systems
Rx.
No Rx.
Rx. Often Absent!
Untreated/poorly treated wastewater is discharged to land or
natural waters
Water, Disease and Health
• Water-borne
– Exposure mainly by ingestion of contaminated water
– Primarily enteric diseases transmitted by the fecal-oral
route
• Water-washed
– exposure is reduced by water use for personal and
domestic hygiene: washing (clothes, floors, other
household chores), bathing & other personal hygiene
• Water contact and water vector-borne
– Exposure by skin contact with infested water
• Ex: schistosomiasis
– Exposure to water habitat "insect vector" diseases
The Microbial World: Types and Sizes of Microbes
SOME BAD ONES!
Norovirus
Hepatitis A&E
Rotaviruses
Polio-/enteroviruses
Cholera
Diarrhea
Dysentery
Typhoid fever
Amebic dysentery
Giardiasis
BACTERIUM
~ 1 µM
Helminth (Worm)
(eggs shed in feces)
>30 microns
(Ascaris lumbricoides)
Waterborne Pathogens Come Primarily from
Feces by Various Routes of Exposure
Excreta from humans and animals
Land
Runoff
Sewage
Solid Waste
Landfills
Oceans and
Estuaries
Rivers and
Lakes
Groundwater
Irrigation
Crops
Aerosols
Shellfish
Recreation
Water
Supply
Human
E. coli from Spinach
Lettuce & Tomatoes!
Adapted from Charles P. Gerba et al. 1975
Issues in Water and Health
• Quality
• Quantity
• Access
• Habitat and Ecology
• Resources and Management
• Economics
• Behavior and Beliefs
• Enabling Environment and Policies
Analyzing the Role of WSH in Reducing
Disease
Recent metaanalysis
shows major
impacts by
• Hygiene
• Sanitation
• Water quality
• Water supply
Comparison of Impacts of WSH Interventions:
Fewtrell et al. 2005 vs. Previous Studies
All Studies
Good Studies
• Water quality interventions (POU water Rx) was more effective than previously thought
• Multiple interventions (combined WSH) were not more effective than single interventions (?)
Piped and Non-Piped Water Supplies
• Most people lack piped water
• They collect water or have it delivered
• Most wells in developing countries deliver NO or
UNSAFE water!
• Sources are often contaminated
• Piped water is often contaminated
• Classified as “improved”, but still unsafe
Piped and Non-Piped Water Supplies
• Collected, stored water often becomes
contaminated in the home
• Water is often not treated, but used directly
• Boiling is widely practiced
• Disadvantages:
–
–
–
–
–
Cost
Inconvenience
no residual protection (gets recontaminated in use!)
environmental degradation (deforestation)
air pollution (health effects)
Barriers against Microbial Contamination
and Waterborne Disease
• Collect from a safe source
• Store it with contamination safeguards:
• Treat water to reduce microbial contamination
– Physical treatments:
• Heat, sunlight (heat + UV), UV lamp radiation &
filtration
– Chemical treatments (disinfection):
• chlorine
– Combined physical-chemical treatments:
• coagulation-flocculation-chlorination
(“conventional Rx”)
Behavioral and Educational Components of
WSH Interventions
Increase awareness of the link
between the 5Fs and disease and the
benefits of appropriate hygiene
behaviors
Behavior change techniques:
•social marketing
•community mobilization
•motivational interviewing
•communication
•education
World Health Organization HealthRisk Based Framework
• Risk-based framework
• Source-to-consumer
management approach
• Establishes health basedtargets for performance
• Can set acceptable level of
risk appropriate to setting
and population
– Establish and carry out
Management Plans
– Independent surveillance
• Integrated. Consistent across, These principles apply to all
types of WSH measures!
compatible with and
applicable to all WSH
measures
WSH, Addressing the Global Burden of
Disease by Working towards Meeting the
MDGs:
Still Plenty to Do
• Research
• Implementation/Dissemination
• Communication
• Advocacy
• Finance
• Policies
• Diplomacy and Politics
Celebrating Water for Life
The International Decade for Action
2005 to 2015
2008: International Year of Sanitation