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Water, Sanitation and Health: the Millennium Development Goals and Reducing the Global Burden of Disease Jamie Bartram With adaptations by Mark Sobsey, UNCChapel Hill Overview Water, poverty and prosperity Water: a health concern? • Disability adjusted life years (DALYs) Who and where are the disadvantaged? Perspectives / trends Why invest in water and sanitation? Water, poverty and prosperity WSH = disease and poverty ? • Inadequate water supply • Time, financial cost • Unsafe water resources • Disease burden • Inequitable access • Health care costs POVERTY WSH = a motor for development • Improved water supply • Time, financial savings • Safe water resources • Averted disease costs • Universal access • Healthy populations Development Water: A health concern? Leading Causes of Deaths from Infectious Diseases 2004 World Health Report 3963 2777 1798 1566 1271 611 R es pi ra to ry In fe ct io ns D H ia IV rrh /A oe ID al S D is ea Tu se s be rc ul os is M al ar ia M ea sl es Deaths (000s) 4500 4000 3500 3000 2500 2000 1500 1000 500 0 Non-fatal health effects Mortality numbers can dominate conversations about health Also concerned about non-fatal health conditions A metric was needed to quantify non-fatal health outcomes, make informed policy decisions and allocate health resources WHO introduced Disability Adjusted Life Years (DALYs) in 1994 Used to assess risks and benefits associated with various diseases, threats to health and interventions Disability Adjusted Life Years DALY = YLL + YLD • YLL – years of life lost due to early death • YLD – years of life lost to disability YLL = N x L • N = number of deaths • L = standard life expectancy at age of death in years YLD = I x DW x L • I = number of incident cases • DW = disability weight • L = average duration of the case until remission or death (years) DALY – 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, GunningSchepers LJ, van der Maas PJ (1997). Disability Weights for Diseases in the Netherlands. Rotterdam: DALY – Graphical Example Disability weight 1 0.8 0.6 Acute (infectious) disease 0.4 0.2 Premature death 0 0 20 40 60 Age Residual disability 80 How much disease could be prevented by modifying the environment? Prüss-Ustün and Corvalán (2007) How Much Disease Burden can be Prevented by Environmental Interventions?, Epidemiology, 18:1, p. 167-178. Reduction (%) Diarrhoeal disease reduction from drinking water and sanitation improvements 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 Intervention GBD – Selected water-related diseases • Diarrhoea: 1.8 million people, mostly children, die of diarrhoea every year Malaria: 1 million people, mostly children, die of malaria every year Better management of water resources reduces transmission • Schistosomiasis: 200 million are infected, 20 million suffer severe consequences Basic sanitation reduces the diseases by up to 77% • Trachoma 6 million visually impaired, 146 million threatened by blindness Improved sanitary conditions and hygiene practices prevents trachoma The more we know, the more environment matters In addition (2010?) Total disease 2005 5% 4% 3% 2002 WSH caused diarrhoea and parasitic diseases Water hardness and heart disease, hepatitis A and E, fluorosis, arsenicosis, typhoid fever etc. Also WSH-caused malnutrition ? Who and where are the disadvantaged? Improved Drinking Water: Status in 2002 Coverage of improved drinking water sources, 2002 Percentage of population using improved drinking water sources Less than 50% 50 - 75% 76 - 90% 91 - 100% missing data Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of Progress WHO and UNICEF, 2004 WHO/OMS Improved Sanitation: Status in 2002 Sanitation coverage, 2002 Percentage of population using improved sanitation Less than 50% 50 - 75% 76 - 90% 91 - 100% missing data Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of Progress WHO and UNICEF, 2004 WHO/OMS Improved Sanitation: Unserved population by region, 2002 (millions) Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of Progress WHO and UNICEF, 2004 Disparities Masked by National Averages: Rural versus urban sanitation (2002) Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of Progress WHO and UNICEF, 2004 Perspectives / trends Reaching the MD Goals from 2002: What does it mean for Goal 7 Target 10? To halve, between 1990 and 2015, the proportion of the population without improved drinking water and sanitation now means means: Enabling an additional 260,000 people a day up to 2015 to use improved drinking water sources Enabling an additional 370,000 people a day up to 2015 to use improved sanitation Ensuring continuation of services to an unprecedented population and maintenance and renewal of infrastructure Reaching the MD Goals from 2002: Focusing G7 T10 on the wider goals Reaching the target would: • Reduce disease and death •Improve nutrition and food security • Reduce poverty (avert health care costs, time savings) Unserved, children and women likely to benefit most (health and education) Studies show WS&S to be cost effective Improved Drinking Water: Trends in service levels Un-served Other 'improved drinking water source' Piped water at home Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of Progress WHO and UNICEF, 2004 Improved Sanitation: Perspectives Population (in billions) 3,0 2.7 bn 2,5 2.4 bn 2,0 1.9 bn 1,5 1,0 0,5 0,0 1990 2002 2015 If on track to reach the MDG target Current trend Meeting the MDG Drinking Water and Sanitation Target: Mid-term Assessment of Progress WHO and UNICEF, 2004 Population change 1990-2030 9 8 7.5 Population (billions) 7.2 7 5.7 6 6.1 6.5 7.9 6.8 5.3 4.9 5 3.5 4 3 3.1 3.2 3.3 2.9 3.2 3 2.3 2 8.1 2.6 3.3 3.9 3.3 4.2 3.3 4.6 3.3 3.2 1 0 1990 95 00 05 10 15 20 25 30 Year Change 1990-2002 Change 1990-2015 Global: 18% Global: 37% Urban: 31% Urban: 70% Rural: 8% Rural: 12% Global population Urban population Rural population Reaching the MD Goals from 2002: Focusing G7 T10 on the wider goals Reaching the target would: • Reduce disease and death •Improve nutrition and food security • Reduce poverty (avert health care costs, time savings) 1 billion urban dwellers to keep up with urban population growth – targetting slums Unserved, children and women likely to benefit most (health and education) Studies show WS&S to be cost effective 900 million rural dwellers to start to deal with the rural backlog Why invest in water and sanitation? Introduction of Municipal Water Treatment in the United States Introduction of Municipal Water Treatment in the United States Annual cost of not dealing with water and sanitation Lives lost 1.8 million annually due to diarrhoea alone Health care costs: USD7 billion per year to health agencies USD340 million to individuals Value of time lost USD 63 billion per year 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 Interventions 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 (lowtech) for all by 2015. Increasing access to improved WS&S services (lowtech) 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$ per DALY averted) 900 800 Disinfection 700 Halve pop w/o access to WS 600 500 Halve pop w/o access to WS&S 400 300 Improved water supply and basic sanitation 200 100 - AFRO D AFRO E AMRO D EMRO D SEARO D Piped water supply and sewer connection Macro relevance? High malaria versus low malaria countries: 1% difference in annual GDP growth Cholera in Latin America in 1990’s 3.7% average annual growth by poor countries with improved W&S (as opposed to 0.1% for those without) Suggested Reading: Pruss-Ustun, A. and C. Corvalan (2007) How much disease burden can be prevented by environmental interventions? Epidemiology. 18(1):167-78. Further Topic Details at: www.who.int/water_sanitation_health/