1. Thursday January 15th 2008 International Confernence in Dhaka Community Hospital Richard Wilson Mallinckrodt Research Professor of Physics Harvard University The importance of Chlorinatio in Bangladesh http://arsenic.ws http://physics.harvard.edu/~wilson/arsenic/ arsenic_project_introduction.html

2. KERATOSIS BOWEN”S CARCINOMA DYSPIGMENTATION GANGRENE

3. 1982: R.C Saha observed keratoses and dyspigmentation in West Bengal -IGNORED 1995 DCH physicians saw lesions in Bangladesh. 30,000,000 drinking water with >50 ppb arsenic ACTION BEGAN in 1998 (1) Use uncontaminated deep aquifer (2) Treat the water at household level (3) return to surface waters ALL WILL WORK At this meeting we address only the last Surface wells

4. WHO guidelines for construction No bucket to get water Animals cannot fall in Far from latrines Flood water cannot enter But not enough in a tropical climate

5. Sanitary well: no animals fall in no buckets! (L) Electrically pumped to tank (R) Lady has running water for first time in history

6. Piped water system very popular among women who carry the water Enables more families to be served by one well. Large (INDARA) wells can serve 50 families (1) Maintenance cost spread (2) Large size ensures oxidization and inhibits arsenic release (3) Measurements by Golam Mostafa even in 2007 mosonn show bacteria leels tolerable. Marvellous lEts do more! BUT not yet accptable: Lets do better!

7. >10 after 23 days and reached from 35 to 180+ in the water samples of all dugwells at the end of the month. Fig 1: Faecal coliforms count in water samples of 10 dugwells (DW2, DW3, DW6, DW7, DW8, DW10, DW21, DW29, DW34, and DW66) of Pabna district in the month of July. No. of days after chlorination Fae cal coli for m cou n/ 100 ml

10. To compare different health outcomes Murray (HSPH) recommended (1991) Disability Adjusted Life Years lost (DALYs) Quality Adjusted Life Years lost (QALYs) Faecal coliform is an indicator of problems. Bacterial disease depend on conditioning Few people in Bangaldesh looked for it, DCH was better, but not frequent enough and after, nor before cleaning Ahmed and Howard in 2005 took a selection of wells from various technologies dugwells seemed bad MEDIAN Faecal coliform was 3500 /100ml DCH was at or below 5th percentile

11. DALYs calculated byAhmed and Howard for a NON RANDOM sample of Bangladesh technologies DCH (Pabna) wells are at or below lower (5%) bound of dugwells

12. Chlorination method of DCH: Shock Chlorination Does not work for flooded tube wells. (Luby, Johnston 2006) Works for sufcae dugwells BUT CHLORINE TASTE IS NOT GOOD Canadaian recipe: Minimum resuiual chlorine 0.01 to o.02 mg/Liter 1/50 of that used by DCH for shock treatment Center for Disease Control USA (CDC) up to 1 mg/Liter CDC presents to DCH a kit for measuring free Chloine In last 10 years we have lots of measurements

15. A lot of work on Chlorination at Point of Use Karachi, Zambia, Kenya, and Bolivia vey polluted wells but diarhea reduced Cost less than bottled water Maybe in Dhaka

16. MY recommendation for Bangladesh If deep tube wells ONLY FOR HOUSEHOLD: NEVER FOR IRRIGATION Use surface waters for irrigation ONLY build to WHO standards (DCH) River water filters Pond sand fikters Dugwells Chlorine (household bleach every evening (chlortech) adequate to get 0.o2 mg/L Use piped water system; it leads to the long term emphasize large systems: Indara wells

17. ALL DCH tests are on the web at: http://DCHTests.arsenic.ws http://physics.harvard.edu/~wilson/ arsenic/remediation/dugwells/DCHtests Some project well tests also: