Transcript Global Water Sanitation and Health: What this Course is about Mark D.

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 drinkingwater, 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)
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 the house or yard from public distribution
systems, protected wells and springs, public stand posts, rain
water collection; 17% of world population
• 2.6 billion (42% of population) lack access to basic sanitation
– sewerage, on-site septic waste treatment system, latrine
• 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 drinking-water are
rural dwellers, but future populations will be mainly urban
• Peri-urban slums are among the most underserved and
unsanitary places on earth
Lack of WSH = Disease and Poverty
• Inadequate water supply
• Time, financial cost
• Unsafe water resources
• Disease burden
• Inequitable access
• Health care costs
POVERTY
WSH = An Engine for Development and Productivity
• Improved water supply
• Time, financial savings
• Safe water resources
• Averted disease costs
• Universal access
• Healthy populations
Development
UN Millennium Declaration
Overall Goal: Poverty Reduction
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:
Five F’s of WSH
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Feces
Fingers
Flies
Fields/Food
Fluids
Fomites
Water Treatment
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
Roman latrine
have serious deficiencies
• Sanitation is one of the
biggest technological
gaps we have globally
• Pathogens go
VIP latrine
Latrine
everywhere as a result
Inferior/No Community Wastewater Treatment Systems
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
Norovirus
Hepatitis A&E
Rotaviruses
Polio-/enteroviruses
Cholera
Diarrhea
Typhoid fever
Dysentery
Amebic dysentery
Giardiasis ( bever fever)
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
Adapted from Charles P. Gerba et al. 1975
Spinach!
E. coli
Issues in Water and Health
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Quality
Quantity
Access
Habitat and Ecology
Resources and Management
Economics
Behavior and Beliefs
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 (?)
Handwashing Hygiene to
Prevent Disease
• Handwashing with soap
and water after contact
with fecal material can
reduce diarrheal diseases
by 35% or more
Source: Almedom et al. 1997
Piped and Non-Piped Water Supplies
• Most people lack piped water
– They collect water or have it delivered
• Sources are often contaminated (UNSAFE!)
• Piped water is often contaminated
– Classified as “improved” but UNSAFE!
• Collected, stored water often becomes
contaminated in the home (UNSAFE!)
• Water is often not treated – used directly
• Boiling is widely practiced, but……
– 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 Health-Risk
Based Framework
• Risk-based framework
• Source-to-consumer
management approach
• Establishes health based-targets
for performance
• Can set acceptable level of
risk appropriate to setting and
population
– Establish and carry out
Management Plans
– Independent surveillance
• Integrated. Consistent across,
compatible with and applicable to
all WSH measures
These principles apply to all
types of 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