Jamie BartramJamie Bartram

With adaptations by With adaptations by Mark Sobsey, UNC-Mark Sobsey, UNC-Chapel HillChapel Hill

Water, Sanitation and Health: Water, Sanitation and Health: the Millennium Development Goalsthe Millennium Development Goalsand Reducing the Global Burden of and Reducing the Global Burden of

DiseaseDisease

OverviewOverview

Water, poverty and prosperity Water, poverty and prosperity Water: a health concern?Water: a health concern?

• Disability adjusted life years (DALYs)Disability adjusted life years (DALYs) Who and where are the Who and where are the

disadvantaged?disadvantaged? Perspectives / trends Perspectives / trends Why invest in water and sanitation?Why invest in water and sanitation?

Water, poverty and Water, poverty and prosperity prosperity

WSH = disease and poverty ?WSH = disease and poverty ?• Inadequate water supply

• Unsafe water resources

• Inequitable access

• Time, financial cost

• Disease burden

• Health care costs

POVERTY

WSH = a motor for developmentWSH = a motor for development

• Improved water supply

• Safe water resources

• Universal access

• Time, financial savings

• Averted disease costs

• Healthy populations

Development

Water: A health concern? Water: A health concern?

3963

2777

1798 15661271

611

0500

10001500200025003000350040004500

De

ath

s (

00

0s

)Leading Causes of Deaths from Infectious DiseasesLeading Causes of Deaths from Infectious Diseases

2004 World Health Report

Non-fatal health effectsNon-fatal health effects

Mortality numbers can dominate Mortality numbers can dominate conversations about health conversations about health

Also concerned about non-fatal health Also concerned about non-fatal health conditionsconditions

A metric was needed to quantify non-fatal A metric was needed to quantify non-fatal health outcomes, make informed policy health outcomes, make informed policy decisions and allocate health resourcesdecisions and allocate health resources

WHO introduced Disability Adjusted Life WHO introduced Disability Adjusted Life Years (DALYs) in 1994Years (DALYs) in 1994

Used to assess risks and benefits Used to assess risks and benefits associated with various diseases, threats to associated with various diseases, threats to health and interventionshealth and interventions

Disability Adjusted Life YearsDisability Adjusted Life Years

DALY = YLL + YLDDALY = YLL + YLD• YLL – years of life lost due to early deathYLL – years of life lost due to early death• YLD – years of life lost to disabilityYLD – years of life lost to disability

YLL = N x LYLL = N x L• N = number of deaths N = number of deaths • L = standard life expectancy at age of death in L = standard life expectancy at age of death in

yearsyears

YLD = I x DW x LYLD = I x DW x L• I = number of incident cases I = number of incident cases • DW = disability weight DW = disability weight • L = average duration of the case until L = average duration of the case until

remission or death (years) remission or death (years)

DALY – Example Disability WeightsDALY – Example Disability Weights

Weight Disease/stage

0.00-0.01 Gingivitis, caries

0.01-0.05 Mild asthma, mild vision loss, mild hearing loss, basal cell skin cancer

0.05-0.10 Low back pain, uncomplicated diabetes case, mild angina

0.10-0.15 Mild depression, osteoarthritis (grade 2), epilepsy

0.15-0.20 Mild/mod. panic disorder, spina bifida (sacral), HIV positive

0.20-0.30 Breast cancer (disease free), anorexia, mild/mod. obsessive- compulsive disorder

0.30-0.40 Moderate depression, relapsing MS, severe asthma, chronic Hep B, deafness

0.40-0.50 Blindness, spina bifida (L3-L5), osteoarthritis (grade 3-4)

0.50-0.65 Paraplegia, AIDS (1st stage), Down syndrome, severe PTSD

0.65-0.8 Cancer (diagnostic/treatment), severe depression, brain injury

0.8-1.0 Disseminated cancer, severe dementia, severe schizophrenia, quadriplegia

1 Stouthard MEA, Essink-Bot ML, Bonsel GJ, Barendregt JJ, Kramer PG, van de Water HPA, Gunning-Schepers LJ, van der Maas PJ (1997). Disability Weights for Diseases in the Netherlands. Rotterdam:

DALY – Graphical ExampleDALY – Graphical Example

0

0.2

0.4

0.6

0.8

1

0 20 40 60 80

Age

Dis

abili

ty w

eig

ht

Residual disability

Premature deathAcute

(infectious) disease

Prüss-Ustün and Corvalán (2007) How Much Disease Burden can be Prevented by Environmental Interventions?, Epidemiology, 18:1, p. 167-178.

.

How much disease could be prevented How much disease could be prevented by modifying the environment?by modifying the environment?

Diarrhoeal disease reduction from drinking Diarrhoeal disease reduction from drinking water and sanitation improvementswater and sanitation improvements

Red

ucti

on (

%)

Intervention

Source: Fewtrell L et al. Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and meta-analysis.Lancet Infectious Diseases, 2005

• Diarrhoea:1.8 million people, mostly children, die of diarrhoea every year Malaria:1 million people, mostly children, die of malaria every yearBetter management of water resources reduces transmission

• Schistosomiasis:200 million are infected, 20 million suffer severe consequencesBasic sanitation reduces the diseases by up to 77%

• Trachoma6 million visually impaired, 146 million threatened by blindnessImproved sanitary conditions and hygiene practices preventstrachoma

GBD – Selected water-related diseasesGBD – Selected water-related diseases

The more we know, the more The more we know, the more environment mattersenvironment matters

?2002

WSH caused diarrhoea and

parasitic diseases

2005

Also WSH-caused malnutrition

In addition (2010?)

Water hardness and heart disease, hepatitis A and E,

fluorosis, arsenicosis, typhoid fever etc.

3%

4%

5%

To

tal

dis

ease

Who and where are the Who and where are the disadvantaged? disadvantaged?

WHO/OMSWHO/OMS

Percentage of populationusing improved drinking water sources

Less than 50%50 - 75%76 - 90%91 - 100%missing data

Coverage of improved drinking water sources, 2002

Improved Drinking Water:Improved Drinking Water:Status in 2002Status in 2002

Meeting the MDG Drinking Water and Sanitation Target: Mid-term Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of ProgressAssessment of ProgressWHO and UNICEF, 2004WHO and UNICEF, 2004

WHO/OMSWHO/OMS

Percentage of populationusing improved sanitation

Less than 50%50 - 75%76 - 90%91 - 100%missing data

Sanitation coverage, 2002

Improved Sanitation:Improved Sanitation:Status in 2002Status in 2002

Meeting the MDG Drinking Water and Sanitation Target: Mid-term Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of ProgressAssessment of ProgressWHO and UNICEF, 2004WHO and UNICEF, 2004

Improved Sanitation:Improved Sanitation:Unserved population by region, 2002 (millions)Unserved population by region, 2002 (millions)

Meeting the Meeting the MDG MDG Drinking Drinking Water and Water and Sanitation Sanitation Target: Target: Mid-term Mid-term Assessment Assessment of Progressof Progress WHO and WHO and UNICEF, UNICEF, 20042004

Disparities Masked by National Averages:Disparities Masked by National Averages:Rural versus urban sanitation (2002)Rural versus urban sanitation (2002)

Meeting the Meeting the MDG MDG Drinking Drinking Water and Water and Sanitation Sanitation Target: Target: Mid-term Mid-term Assessment Assessment of Progressof Progress WHO and WHO and UNICEF, UNICEF, 20042004

Perspectives / trends Perspectives / trends

Reaching the MD Goals from 2002:Reaching the MD Goals from 2002:What does it mean for Goal 7 Target 10?What does it mean for Goal 7 Target 10?

To halve, between 1990 and 2015, the proportion of the To halve, between 1990 and 2015, the proportion of the

population without improved drinking water and sanitation population without improved drinking water and sanitation

now means means:now means means:

Enabling an additional Enabling an additional 260,000 people a day up 260,000 people a day up to 2015 to use improved to 2015 to use improved drinking water sourcesdrinking water sources

Enabling an Enabling an additional 370,000 additional 370,000

people people a daya day up to up to 2015 to use improved 2015 to use improved

sanitationsanitation

Ensuring continuation of services to an unprecedented Ensuring continuation of services to an unprecedented population and maintenance and renewal of infrastructure population and maintenance and renewal of infrastructure

Reaching the MD Goals from 2002:Reaching the MD Goals from 2002:Focusing G7 T10 on the wider goalsFocusing G7 T10 on the wider goals

Reaching the target would:Reaching the target would:

• Reduce disease and deathReduce disease and death

•Improve nutrition and food Improve nutrition and food

securitysecurity

• Reduce poverty (avert health Reduce poverty (avert health

care costs, time savings)care costs, time savings)

Unserved, children and Unserved, children and

women likely to benefit women likely to benefit

most (health and education)most (health and education)

Studies show WS&S to be Studies show WS&S to be

cost effectivecost effective

Improved Drinking Water:Improved Drinking Water:Trends in service levelsTrends in service levels

Un-servedUn-served

Other 'improved drinking water source'Other 'improved drinking water source'

Piped water at homePiped water at home

Meeting the Meeting the MDG MDG Drinking Drinking Water and Water and Sanitation Sanitation Target: Target: Mid-term Mid-term Assessment Assessment of Progressof Progress WHO and WHO and UNICEF, UNICEF, 20042004

Improved Sanitation:Improved Sanitation:PerspectivesPerspectives

0,0

0,5

1,0

1,5

2,0

2,5

3,0

1990 2002 2015

Po

pu

lati

on

(in

bill

ion

s)

If on track to reach the MDG targetCurrent trend

1.9 bn

2.4 bn

2.7 bn

Meeting the Meeting the MDG MDG Drinking Drinking Water and Water and Sanitation Sanitation Target: Target: Mid-term Mid-term Assessment Assessment of Progressof Progress WHO and WHO and UNICEF, UNICEF, 20042004

Population change 1990-2030

8.1

5.35.7

6.16.5

6.87.2

7.57.9

4.9

3.94.2

4.6

2.32.6

2.9 3.2

3.5

3.23.33.33.33 3.1 3.2 3.3

3.3

0

1

2

3

4

5

6

7

8

9

Year

Po

pu

lati

on

(b

illi

on

s)

Global population

Urban population

Rural population

1990 95 00 05 10 15 20 25 30

Change 1990-2002

Global: 18%

Urban: 31%

Rural: 8%

Change 1990-2015

Global: 37%

Urban: 70%

Rural: 12%

Reaching the MD Goals from 2002:Reaching the MD Goals from 2002:Focusing G7 T10 on the wider goalsFocusing G7 T10 on the wider goals

Reaching the target would:Reaching the target would:

• Reduce disease and deathReduce disease and death

•Improve nutrition and food Improve nutrition and food

securitysecurity

• Reduce poverty (avert health Reduce poverty (avert health

care costs, time savings)care costs, time savings)

1 billion urban dwellers to 1 billion urban dwellers to keep up with urban keep up with urban population growth – population growth –

targetting slumstargetting slums

900 million rural dwellers 900 million rural dwellers to start to deal with the to start to deal with the

rural backlogrural backlog

Unserved, children and Unserved, children and

women likely to benefit women likely to benefit

most (health and education)most (health and education)

Studies show WS&S to be Studies show WS&S to be

cost effectivecost effective

Why invest in water and Why invest in water and sanitation?sanitation?

Introduction of Municipal Water Introduction of Municipal Water Treatment in the United StatesTreatment in the United States

Introduction of Municipal Water Introduction of Municipal Water Treatment in the United StatesTreatment in the United States

Annual cost of not dealing with Annual cost of not dealing with water and sanitationwater and sanitation

Lives lostLives lost 1.8 million annually due to diarrhoea 1.8 million annually due to diarrhoea

alonealone

Health care costs:Health care costs: USD7 billion per year to health agenciesUSD7 billion per year to health agencies USD340 million to individualsUSD340 million to individuals

Value of time lostValue of time lost USD 63 billion per yearUSD 63 billion per year

Cost-benefit analysis (CBA)Cost-benefit analysis (CBA)

The aim of the study was to estimate:

the costs (capital and recurrent) the health benefits (diarrhoea cases and deaths) the additional benefits (costs averted, time saved)

Results presented as US$ per year, per capita , per intervention.

Note that these methods are highly dependent upon assumptions and that there are numerous data gaps

InterventionsInterventions

5 interventions were modelled: Halving population w/o improved WS by 2015 (through low-tech

services). Halving population w/o improved WS&S by 2015 (through low-tech

services) (MDG 7). Increasing access to improved WS&S services (low-tech) for all by 2015. Increasing access to improved WS&S services (low-tech) plus

disinfection at point of use, for all by 2015. Increasing access to in-house piped water and sewer connection for all

by 2015.

Cost-effectiveness ratios (US$ Cost-effectiveness ratios (US$ per DALY averted)per DALY averted)

-

100

200

300

400

500

600

700

800

900

AFRO D AFRO E AMRO D EMRO D SEARO D

Disinfection

Halve pop w/oaccess to WS

Halve pop w/oaccess to WS&S

Improved watersupply and basicsanitation

Piped watersupply and sewerconnection

Macro relevance?Macro relevance?

High malaria versus low malaria High malaria versus low malaria countries: 1% difference in annual countries: 1% difference in annual GDP growthGDP growth

Cholera in Latin America in 1990’sCholera in Latin America in 1990’s 3.7% average annual growth by 3.7% average annual growth by

poor countries with improved W&S poor countries with improved W&S (as opposed to 0.1% for those (as opposed to 0.1% for those without)without)

Further Topic Details at:Further Topic Details at:www.who.int/water_sanitation_healthwww.who.int/water_sanitation_health//

Suggested Reading:

Pruss-Ustun, A. and C. Corvalan (2007) How much disease burden can be prevented by environmental interventions? Epidemiology. 18(1):167-78.