1. The Impact of Dams and Reservoirs on Public Health Teresa Yamana 1.096 Env. Eng. Clinic Merowe Dam Group March 8, 2004

2. Health Issues Involving Water Waterborne Water contaminated by human, animal, chemical waste eg. Cholera,typhoid Water-based Organisms living in water eg. Schistosomiasis Water-related Transmitted by vectors living in or around water eg. Malaria Water-washed Preventable by increased hand-washing eg. trachoma

3. Dams’ Threat to Public Health Stagnant water in reservoirs and irrigation ditches provide habitat for vectors Constant supply of water - Dry season no longer limits vectors Relocated population

4. Merowe Health Impact Analysis Conducted by Blue Nile Associates 27 major health impacts 7 positive Less river blindness Less diarrhea Less malnutrition 20 negative More malaria More schistosomiasis More river blindness Rift Valley Disease

5. Malaria single-celled protozoa Plasmodium transmitted by Anopheles mosquitoes causes 1 million deaths per year fever-like symptoms high resistance to drugs

6. Malaria - prevention and control bednets and window screens drugs habitat reduction insecticides WHO/TDR/Crump

7. Schistosomiasis (Biharzia) Schistosoma fluke carried by snails transmitted through water Fishermen, farmers especially at risk severe damage to urinary tract, abdomen, spleen, liver enters water via urine and feces - Sanitation!! WHO/TDR WHO/TDR/Stammers

8. Schistosomiasis WHO/TDR/Don-Arthur WHO/TDR/Crump

9. River Blindness (Onchocerciasis) Onchocerca volculus worm transmitted by blackfly causes itching, depigmentation, blindness lives in humans 14 yrs flies breed in fast- moving water WHO/TDR/Stammers WHO/TDR/OCP

10. Rift Valley Fever Viral disease - causes lethal hemorrhaging Transmitted by ticks and mosquitoes Predominantly found in sheep and cattle Occurs when dam filled for first time or after drought - explosion in vector population Two major epidemics at Aswan Dam, three along dams on Senegal River

11. Some Mitigation Strategies Minimize vector habitat Destroy vector populations Locate settlements away from vector habitats Provide clean water and sanitation, health education, health facilities to resettled communities Screen newcomers for diseases Manage water level and shoreline of reservoir

12. Engineering data for disease prevention Source: Jobin, W. Dams and Diseas, 1999