‘Water quality: addressing global problems at source’, Presentation by Dr Jim Wright, Geography and Environment, University of Southampton. Multidisciplinary Research Week 2013. #MDRWeek.
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‘Water quality: addressing global problems at source’, Presentation by Dr Jim Wright, Geography and Environment, University of Southampton. Multidisciplinary Research Week 2013. #MDRWeek.

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Multidisciplinary Research Week 2013 at the University of Southampton. #MDRWeek. World Water Day and International Year of Water Cooperation 2013. ...

Multidisciplinary Research Week 2013 at the University of Southampton. #MDRWeek. World Water Day and International Year of Water Cooperation 2013.
Water quality: addressing global problems at source’, Presentation by Dr Jim Wright, Geography and Environment, University of Southampton.
See the latest videos, interviews, pictures, tweets and views from the floor at: www.southampton.ac.uk/multidisciplinary

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‘Water quality: addressing global problems at source’, Presentation by Dr Jim Wright, Geography and Environment, University of Southampton. Multidisciplinary Research Week 2013. #MDRWeek. ‘Water quality: addressing global problems at source’, Presentation by Dr Jim Wright, Geography and Environment, University of Southampton. Multidisciplinary Research Week 2013. #MDRWeek. Presentation Transcript

  • World Water Day: Water Cooperation Multidisciplinary Research Week 2013‘Water quality: addressing global problems at source’, by Dr Jim Wright, Geography and Environment, University of Southampton.
  • Water quality: addressing global problems at source Dr. Jim Wright, Geography and Environment University of Southampton
  • The Millennium Development GoalTarget 7C:‘Halve, by 2015, the proportion of the population withoutsustainable access to safe drinking water and basic sanitation’ http://www.un.org/millenniumgoals/ View slide
  • Millennium Development Goal for Water – Met?NEW YORK/GENEVA, 6 March 2012 – The world has met the MillenniumDevelopment Goal (MDG) target of halving the proportion of people withoutsustainable access to safe drinking water, well in advance of the MDG 2015deadline, according to a report issued today by UNICEF and the World HealthOrganization (WHO). Between 1990 and 2010, over two billion people gained accessto improved drinking water sources, such as piped supplies and protected wells.United Nations Secretary-General Ban Ki-moon said, “Today we recognize a greatachievement for the people of the world. This is one of the first MDG targets to bemet….” (http://www.wssinfo.org/) View slide
  • The Joint Monitoring Programme (JMP) classification ofimproved (safe) and unimproved (unsafe) source types Source class Types of source included Improved: Piped into dwelling, plot, or yard Piped water connection located inside the user’s dwelling, plot, or yard. Improved: other sources Public taps or standpipes, tube wells or boreholes, protected dug wells, protected springs, or rainwater collection. Unimproved drinking water sources Unprotected dug well, unprotected spring, cart with small tank/drum, surface water (river, dam, lake, pond, stream, canal, irrigation channels), and bottled water. (http://www.wssinfo.org/definitions-methods/watsan-ladder/)
  • Photo: Jim Wright
  • Rapid Assessment of Drinking Water Quality (RADWQ)
  • Rapid Assessment of Drinking Water Quality (RADWQ) Nationally representative sampling of water as consumed Cr0ss-sectional Parameters of major public health concern Thermotolerant coliforms Arsenic Fluoride nitrate
  • A comparison of 1990 baseline, 2008 coverage and progress towards 2015 targets based on(i) access to improved sources, as published by JMP (ii) improved and ‘microbiallycompliant’ sources as adjusted using the RADWQ and (iii) improved and ‘overall compliant’sources for five countries.a. Tajikistan is based on 1995 data and that Jordan estimates for 2008 are the same as 1990 except for (i) where itis 1% lower. (Bain, et al., Bulletin of the World Health Organization 90:228–235A, 2012)
  • Dimensions of safe water access Quality – safety and aesthetics Available – quantity and continuity Affordable Accessible Non-discriminatory Collection time Sustainable – environmental, financial, organisational Equitable
  • Socio-economic inequality in safe water access (The Millennium Development Goals Report 2011)
  • Peruvian piped water users (Yang, et al., Environmental Science & Technology 47: 1222-1230, 2013)
  • Bangladeshi tubewell users (Yang, et al., Environmental Science & Technology 47: 1222-1230, 2013)
  • Water testing in remote locations Source: Ince et al (2010)
  • Photo: Melissa Loudon, University of Cape Town
  • Photo: Melissa Loudon, University of Cape Town
  • Studies of diagnostic accuracy E. coli or thermotolerant coliform test resultH2S test result Positive Negative true positive false positivePresent (tp) (fp) false negative true negativeAbsent (fn) (tn)
  • Literature review: search terms Terms for H2S test Terms for standard tests (e.g. hydrogen sulphide (e.g. fecal coliform hydrogen sulfide faecal coliform Pathoscreen, H2S) thermotolerant coliform E. Coli) Terms for water samples (water)
  • Literature Review: Results(Wright et al. Tropical Medicine and International Health 17: 94-105, 2012)
  • How does H2S test typically perform?In B, the three crosses in the top left corner represent the sensitivities and specificities of a.Colilert (Edberg et al., 1988), b. Colitag (NEMI, 2009), c. Colisure (McFeters et al., 1995). (Wright et al. Tropical Medicine and International Health 17: 94-105, 2012)
  • Contamination rates are important True positives Lab test False positives resultH2S test result Present AbsentPositive 191 36Negative 29 244Total 220 280H2S test sensitivity1 0.87H2S test specificity1 0.82Water source contamination rate(from RADWQ Survey)2 44%H2S test positive predictive value 0.841: Source – Wright et al, 2012; 2: Source – (Ince et al. 2006); 3: Source – (Ince et al.2006)
  • Contamination rates are important True positives Lab test False positives resultH2S test result Present AbsentPositive 26 61Negative 4 409Total 30 470H2S test sensitivity1 0.87H2S test specificity1 0.82Water source contamination rate(from RADWQ Survey)2 6%H2S test positive predictive value 0.301: Source – Wright et al, 2012; 2: Source – (Ince et al. 2006); 3: Source – (Ince et al.2006)
  • green / (green + pink) False positives & source contamination (Wright et al. Tropical Medicine and International Health 17: 94-105, 2012)
  • ConclusionsExisting H2S method very cheap….…but variable accuracy Evaluate before useCaution needed with such tests where contaminationuncommonOther alternatives: Aquatest device DelAgua
  • ConclusionsAlthough target 7c met, still substantial populationwithout safe water accessField diagnostics for remote areas could contribute to Measuring safe water access Remediating unsafe sourcesRequires a multi-disciplinary approach
  • AcknowledgementsParticular thanks to Rob Matthews - University of BristolAquatest consortium:Prof. Stephen Gundry, Rob Bain, Rob Matthews - University of BristolDr. Hong Yang – University of SouthamptonProf. Jamie Bartram, Rob Bain – University of North CarolinaDr. Steve Pedley, John Elliott – University of SurreyDr. Kate Walker – London School of Hygiene and Tropical MedicineProf. Ulrike Rivett, Melissa Loudon – University of Cape TownFunding:This research has been funded by the Bill & Melinda GatesFoundation, under a grant to the University of Bristol,whose purpose is to develop a low-cost test of waterquality for use in developing countries.
  • World Water Day: Water Cooperation Multidisciplinary Research Week 2013See the latest videos, interviews, pictures, tweets and viewsfrom the floor at:Website: www.southampton.ac.uk/multidisciplinaryBlog: http://blog.soton.ac.uk/multidisciplinary/tag/mdrweek/Youtube: Search #MDRWeek Follow us on Twitter @Multisoton #MDRWeek