who recommendations for hwts technology performance...

WHO Recommendations for HWTS Technology Performance Evaluation:

The Nuts and BoltsProf. Mark D. Sobsey, PhD

Department of Environmental Sciences and EngineeringGillings School of Global Public Health

University of North CarolinaChapel Hill, NC USA

Email: [email protected]

UNC Water and Health Conference30 October 2012

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Overview

• Introduction to WHO Guidelines for Drinking-water Quality

• Water safety plans

• Household water treatment and safe storage (HWTS)

• International Network

• Criteria to evaluate technologies/methods

• National policies and regulations

• Challenges in HWTS and future needs


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WHO Guidelines for Drinking-water Quality: Background

• History '84/'85 1st edition published; 2011 4th edition published

• Aim -Protection of human health-Support setting of national standards

and regulations• Approach Health risk/benefit, advisory in

nature, multiple barriers, incremental improvements

• Target audience Policy makers, regulators, water suppliers, implementers

• Risk Framework, health based-Risk assessment, i.e. quantitative microbial risk assessment (QMRA)


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A Framework for Safe Drinking Water: WHO Guidelines for Drinking Water Quality

Health-based targets(National regulatory body)

Independent surveillance(Surveillance agency)

Water Safety Plans(Water utility; water provider)


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Household Water Treatment and Safe Storage (HWTS)

• One (interim) way to achieve safe water: treat it at point-of-use (POU)

• Fills a gap in the water supply sector for safe water at POU (Now)

• Empowers communities and households to achieve safe water themselves, at home

• Included in the WHO GDWQ– Embraced by WHO and other

stakeholders• Promoted globally• International WHO Network

BUT…..Which ones really work?


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International Network on HWTS

• Initiated by WHO in 2003; as of 2011 co-hosted with UNICEF

• Over 100 participating organizations (international organizations, NGOs, governments, private entities, academia,......

• Phase II Strategy (2011-2016) aims to:– Support national policy and framework development– Strengthen evidence base– Evaluate and disseminate best practices in

implementation– Realize tangible results in scaling-up


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Overview of WHO Recommendations on HWT Performance

• Goal: Protect the health of HWTS users, increase access to safe water• Audience: certification organizations, governments, regulators, evaluators, manufacturers and implementers• Target pathogens: viruses, bacteria and protozoa • Derivation of targets: Based on Guidelines for Drinking-water Quality risk-based approach •QMRA models, DALYs, log10 microbe reductions• Tiered approach: Highly protective > protective > interim • Lab protocols: Performance verification methods

Provides a rational basis to find out and know what works, in principle and in context


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Rating Log10 reduction:

bacteriaLog10 reduction:

virusesLog10 reduction

protozoa

Highly protective(10-6 DALYs/ P/yr)

≥ 4 ≥ 5 ≥ 4

Protective(10-4 DALYs/ P/yr)

≥ 2 ≥ 3 ≥ 2

Interim Achieves “protective” target for two classes of pathogens and results in health gains

Performance Criteria

Examples: Boiling, ultrafilters, combined technologies

Examples: Membrane (micro) filters, flocculant-disinfectant

Examples: Chlorine, ceramic filters, biosand filters


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Labelling, Certification and Regulation(WHO does not endorse or certify technologies)

Recommendations: Locally developed and understood, supply sufficient information to make "informed choice"

Cascade Design, MicrofilterProcter and Gamble, Coag-Floc

99.99999% removal of bacteria and 99.99%

removal of viruses, 99.9% protozoa

Hindustan Unilever, Microfilter

Meets EPA standards for virus and bacteria removal.

P&G packets have been proven to eliminate disease causing microorganisms. P&G packets result in removal of more than 99.99999% of intestinal bacteria (including those that cause cholera), 99.99% of intestinal viruses (including those that cause hepatitis A) and 99.9% of protozoa. P&G packets remove dirt and other pollutants. P&G packets are considered an effective technology by the World Health Organization.

Effective against bacteria and

protozoa.


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Challenges in HWTS and Future Needs

• Improving correct and consistent use• Ensuring vulnerable groups have access to

clean drinking-water (HWTS is one solution)

• Communicating health benefits within greater global health community (HIV/AIDs & TB, malaria, nutrition, and respiratory diseases)

• Ensuring national policies and strategies support selection of optimal devices and make them available in high risk areas

• Utilizing effective delivery and financing mechanisms (cost-recovery, partial subsidy, full-subsidy, good commercial marketing, etc.)

WHO/ R Granich


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Further Information• WHO HWT Performance Recommendationshttp://www.who.int/water_sanitation_health/publications/2011/household_

water/en/index.html

• WHO Drinking-water Guidelines

• Network

http://www.who.int/water_sanitation_health/dwq/guidelines/en/index.html

http://www.who.int/household_water/en/index.html

http://www.waterinstitute.unc.edu/hwts/newsletter(UNC communications portal)

Acknowledgements: Maggie Montgomery and Jennifer de France, World Health Organization, Geneva


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Thank You

Questions? Stanford University/Amy Pickering


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