Water safety frameworks in developing countries: science-policy linkages

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Water safety frameworks in developing countries
science-policy linkages

• Dr Guy Howard, DFID

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Policy and science

• Policy requires evidence the role of science
• BUT other factors social, ethical, political
  also important
• SO policy often evidence-informed rather than
  evidence-based
• Policy works through formal and informal
  processes
• dont get fixated on policy documents

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Policy and science fraught with
mis-understanding

• Scientists think policy-makers do not follow
  evidence
• Policy-makers think scientists narrow technicians
• Further complicated when science is
• Limited in its development in-country
• Small number of voices dominate
• Limited operational research of policy relevance

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Water safety framework science and policy in
action

• Water safety framework comprises (WHO 2004)
• Health-based targets
• Water safety plans
• Surveillance
• Driven by improving public health
• Also allows transparent trade-offs
• Applied in Bangladesh

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Health-based targets and quantitative risk
assessment
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Bangladesh context

• In early 1990s reached 97 coverage in rural
  areas (WHO Unicef 2000) contribution to
  reduced diarrhoea
• 1993 arsenic first detected
• Survey (1999-2000) indicates 27 tubewells
  gt50µg/l and 46 gt10 µg/l (BGS DPHE 2001)
• Blanket testing shows 29 gt 50µg/l (about 20 of
  country total)

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Policy context

• Technologies identified for use in mitigation
• Dug wells
• Rainwater harvesters
• Pond sand filters
• Deep tubewells
• Arsenic-removal technologies
• Surface water use prioritised
• Priority given to 1st 3 technologies
• Others only to be used when these failed

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Risk substitution

• These policy choices equate to Specified
  technology Health-based targets
• BUT no consideration given to risk substitution
• Pathogens
• Cynaobacterial toxins
• Other chemicals (natural or anthropogenic)
• QHRA undertaken to estimate impact of these risks
  and benefits of policy choices

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RAAMO method (abbreviated)

• Representative set of main technologies tested
  monsoon dry season using cluster sampling
• Model developed with output in DALYs for
  microbial arsenic risks
• 3 reference pathogens
• Composite model bacteria, cryptosporidium and
  rotavirus
• Input data from indicator organisms - derived
  relationships to pathogens
• Arsenic disease burden input data direct arsenic
  measurement and focus on main health outcomes

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Model architecture (Howard et al 2007)
Pathogen in sewage
E. coli in sewage
MeasuredTTCfor option
Volume ofwater consumedunboiled locally
RatiopathogenE. coli
RatioTTCE. coli
MeasuredTTClocally
MeasuredE. colilocally
Dose of pathogens
PredictedE. colifor option
Predictedpathogenfor option
Inputs to or outputs from the model
Infection withRotavirus, Shigella,
Cryptosporidium
MeasuredArsenicfor option
Cancer of lung, bladder and skin
Model process steps
Disease Burden for option
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Results Microbial DALYs
Technology Dry season Monsoon season
Dug well 1.11-2 1.34-2
Deep tubewell 6.98-5 1.26-3
Pond sand filter 1.07-2 1.3-2
Rainwater harvester 6.48-3 3.73-3
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Results arsenic DALYs
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WHO reference level of risk

• GDWQ suggests reference levels of risk can be
  used in setting health-based targets
• Suggested 10-6 DALYs broadly equivalent to 10-5
  lifetime cancer risk used in chemical guideline
  derivation
• Conceptually elegant, but poses practical
  problems
• E.g real-life considerations of impact of
  diarrhoea cancer

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RAAMO findings reference risk

• Microbial contaminants
• Reference risk not achievable for any
  technologies year-round
• Arsenic standard already much higher DALY score
  than WHO reference risk
• Not clear how useful the concept of reference
  risk is in such circumstances
• Better to use comparative measures aim for best
  achievable result

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Changes in practice policy

• Chlorination on dug wells and PSFs increasingly
  standard overcame previous resistance
• Led to re-emphasis by implementing agencies on
  technologies with lower health risk
• Review of National Policy and Implementation Plan
  now initiated

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Water safety plans and surveillance
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Water safety plans

• Identified as critical to improving water safety
  from RAAMO
• OM failures particularly highlighted in relation
  to microbial quality
• In principle agreement by all major players that
  should be followed
• BUT needed locally relevant WSPs with evidence
  in-country of their effectiveness

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The process that was followed

• National conference on water quality
• Government, donors NGOs agree need for pilot
  projects
• Workshop to develop a set of draft WSPs for rural
  technologies
• Govt, donors, NGOs involved
• Pilot projects to apply WSPs
• Consolidation of experience and revision of WSPs

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Developing the WSPs

• Generic WSPs developed
• Cover all water supplies with particular
  technology
• Developed using proformas existing knowledge
  and experience

• Systematic assessment of
• hazards,
• degree of risk,
• control measures,
• monitoring,
• validation and
• verification
• Actions plans developed

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Technologies considered

• Protected dug wells
• Pond sand filters
• Rainwater harvesters
• Deep tubewells
• Shallow tubewells

• Piped systems
• From tubewell
• From surface water after multi-stage filtration
• Gravity-fed (minor)
• Later
• Arsenic removal systems

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Pilot projects

• 3 NGOs covering 82 communities across Bangladesh
  (also Unicef/GoB)
• Every major technology addressed
• Baseline, intermediate and final water quality
  assessments undertaken
• Community caretakers supported with pictorial
  monitoring tools

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Key findings

• Reductions in sanitary risks for all technologies
• Microbial quality improved
• Water handling hygiene practices improved
• 12 reduction in diarrhoeal disease in one pilot
  project
• Greater caretaker accountability
• Pictorial tools found useful

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Water quality risk grading scheme
Count per 100ml Category Comments
0 A Very low risk
1-10 B Low risk
11-100 C Intermediate risk
101-1000 D High risk
gt1000 E Very high risk
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Evidence to practice

• All major water rural programmes committed to
  WSPs
• Moved into 2nd edition regular interactions
• Capacity support offered via ITN-BUET (training,
  consultancy)
• See www.buet.ac.bd/itn

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Key lessons

• Bangladesh showed possible to get wide
  stakeholder buy-in
• Important to get all major players agreed on
  single set of products and approaches
• Need to develop more standardised approaches
• More cost-effective
• Consistency and coherence

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Surveillance

• Surveillance protocol developed and approved by
  GoB
• Limited but practical
• Emphasis on cost-effective survey methods
• Very difficult to implement
• Funding for monitoring scarce and very limited

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Implications and conclusions
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Implications

• RAAMO WSPs showed could get change in policy
  and practice
• BUT also highlighted informal as well as formal
  policy processes
• Formal policies relative recent so no immediate
  change likely
• Water Sanitation Program now leading process of
  formal policy review

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Future challenges

• Climate change and impacts on water supply and
  sanitation
• DFID/WHO funding joint work
• Decadal forecasting to 2020 and 2030
• Assessment of technology susceptibility
• Focus on hotpsots and longer-term policy
  implications

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Conclusions

• Bangladesh water safety framework
• Good illustration of policy-science interactions
• Uncertainty could be managed provided transparent
  and quantified
• Evidence based practice important
• Highlighted value of informal as well as formal
  policy processes
• This type of approach needs wider replications