Abstract

1. Dams are an essential form of national infrastructure for utilizing river power, flow stabilization, agriculture and other development purposes. However, transboundary rivers present difficulties because any construction upstream may impact downstream nations. Bangladesh is situated on the alluvial plain of one of the largest deltas in the world, the Ganges-Bramhputra-Meghna delta. The country’s socioeconomic wellbeing largely depends on the rivers that flow from the surrounding neighboring country India. According to the International Convention on Joint River Water, no single country alone can control the trans-boundary rivers without the consent of the downstream river nation. Despite being a signatory of this convention, India has not complied. The ‘Farakka’ dam that India constructed on the Ganges near to the Bangladesh boarder has resulted serious transboundary environmental and ecological damage over the past four decades. The adversities include reduced flow of fresh water, increased salinity in the soil, surface and ground water, intrusion of salt water inland, arsenic contamination, loss of agricultural production, impeded navigation, and destruction of biodiversity in the coastal zone. The situation is becoming challenging as India implements the Rivers Linking Project, which will divert water flow from Bramhaputra and Meghna rivers exposing Bangladesh to severe water scarcity. Furthermore, there will be an increased threat of flood, drought, and earthquake as some dams are proposed to be constructed in a seismic zone. Millions of people in Bangladesh are at high risk of environmental disaster as well as the subsequent, related adverse health outcomes. Abstract Introduction Published and unpublished scientific articles were reviewed for this paper. Secondary data sources were used for strengthening arguments. The data and literature were accumulated via electronic sources using Google Scholar and the Health Sciences Library, JABSOM, University of Hawaii at Manoa. Searches were limited between 1999 and 2011 and relevant key words were used such as ‘dams on rivers and health in Bangladesh’, ‘Trans-boundary Rivers and health in Bangladesh’ and ‘trapping water flow and health in Bangladesh’. Inclusion criteria included: published in English, full article accessible, river water flow and health focus and Bangladesh. A total of 923 articles were found of which 91 were used. Methodology During the past few decades, intrusion of saline water inland and increasing salinity in soil and surface and ground water were observed in coastal areas of Bangladesh. Salinity has encroached more than 100 km inland into domestic ponds, groundwater supplies and cultivated lands through various estuaries and water inletsthat are linked with major rivers. Adverse effects include decreased availability and productivity of agricultural land, increased food insecurity and increased salinity in natural drinkingwater sources. Approx20 mil people living on the coast are affected by salinity in drinking water from natural sources. Evidence suggests that the world’s largest mangrove forest, Sundarbans, near the Bay of Bengal, has been affected by increased salinity intrusion due to reduced flow of water from the Ganges (Bhuiyanet al 2011). During the post-Farakka era there was a continuous inward intrusion of salt water leading to a saline water imbalance in the eco-system and caused the death of trees, various plants and animals. In addition, riverine fisheries in the region have been adversely affected with five million people struggling for their livelihood who primarily live on fish (Gregory et al., 2010). Health problems linked to increased exposure to salinity in the coastal areas in Bangladesh include an increased burden of communicable diseases, hypertension, premature delivery due to (pre) eclampsia, skin diseases, and acute respiratory infection (Khan et al 2011). Among communicable diseases, diarrhea and choleraare most common in the coastal areas. Vibrio cholerae, the bacterium causing cholera, can survive longer in saline waters, making Bangladesh’s coastal belt an ideal breeding ground for the disease agent (Khan et al 2011). India’s construction of dams on the transboundary rivers have caused floods and droughts in Bangladesh. India opens the dams during monsoon season and traps water flow during dry season. The direct health impacts of floods are downing and injuries leading to increased mortality and morbidity, especially among children (Khan et al 2011). For instance, a 2000 landslide in Tibet caused a dam across the river Tsang-po to collapse, releasing a 26-meter wall of water that destroyed every bridge on the Siang in the Indian boarder state of Arunachal Pradesh. The water then rushed through Assam and within a week, devastated parts of Bangladesh. Human casualties and damages to property were extensive (Bhattarai2009). There are mental health and psychological aspects of floods. The interaction between physical and mental health is complex and life stressors like natural disasters can increase susceptibility not only to physical but also to mental illnesses (Khan et al 2011). In addition to outbreaks of infectious diseases due to flood, nutritional deficiencies in women and children were observed due to drought. Droughts may have wide ranging effects on health including malnutrition, infectious diseases, and on forest fires causing air pollution, particularly in low-income countries (Haines et al2006). Epidemiological research found that the diagnosis of hypertension and (pre) eclampsiain women undergoing antenatal checkups was significantly higher in coastal regions than in noncoastal regions (Khan et al 2011). A seasonal pattern to the incidence of hypertension among pregnant women was observed, which coincides with the dry season when salinity in rivers and groundwater is higher. Research found that hypertension in pregnancy is associated with increased rates of adverse maternal and fetal outcomes, both acute and long term, includ­ing impaired liver function, low platelet count, intrauterine growth retardation, preterm birth, and maternal and perinatal deaths (Khan et al2011). Environmental and Health Impacts Conclusions The people of Bangladesh have experienced many adverse health outcomes due to India’s irrational damming of transboundary rivers and their agriculture and biodiversity have been seriously affected. As a resource-poor country, Bangladesh struggles with this situation that is challenging health and economic development and that is violating human rights. According to the International Convention on Joint River Water, no single country alone can control the trans-boundary rivers without the consent of the downstream river nation. India did not abide by these international laws despite being a signatory of this convention. One of the components of the 1996 Treaty was that India must share the design and environmental impact assessment with Bangladesh before building any dam on any common river. Evidence suggests that India never kept its promise regarding the equitable distribution of Ganges water nor shared any information before building dams on common rivers. International mediators including WHO and World Bank need to step forward and advocate for the rational distribution and ethical use of transboundary fresh water between India and Bangladesh. Saline water intrusion potentially affects all 11 Asian mega-deltas and other large deltas such as the Nile and Mississippi. If salinity intrusion in the coasts remains unchecked, a global crisis in freshwater quality and availability will have devastating human implications. References Khan AE et al. Drinking water salinity and maternal health in coastal Bangladesh: implications of climate change. Environ HlthPersp, 2011;119(9):1328-1332. Chen CTA. The Three Gorges Dam: Reducing the Upwelling and thus Productivity in the East China Sea. Geophys Res Let, 2900;27(3):381-383. Adel MM. The background state leading to arsenic contamination of Bengal Basin groundwater. J Water Health, 2005;3(4):435-452. Richter BD et al. Lost in development’s shadow: The downstream human consequences of dams. Water Alt, 2010;3(2):14-42. Lerer LB, Scudder T. Health impacts of large dams. Environ Impact Assess Rev, 1999;19:113–123 Bhuiyan MJAN, Dutta D. Assessing impacts of sea level rise on river salinity in the Gorai river network, Bangladesh. Estuar, Coast Shelf Sci, 2011;96:219-227. Rahaman MM, Varis, O. Integrated water management of the Brahmaputra basin. Natural Resources Forum, 2009;33:60–75. Khan AE et al. Climate change, sea-level rise, & health impacts in Bangladesh. Environment: Sci Pol SustDev, 2011;53(5):18-33. Sood A, Mathukumalli BKP. Managing international river basins: reviewing India–Bangladesh transboundary water issues. Int’l J River Basin Mmgt, 2011;9(1):43–52. Haines A et al. Climate change and human health: impacts, vulnerability, and mitigation. Lancet, 2006:367:2101–09. Bhattarai DP. (). An analysis of transboundary water resources. J Inst Engineer, 2009:7(1):1-7. Gregory NG. Recent concerns about the environment in Bangladesh. Outlook on Agriculture, 2010:39(2):115–120. NIPORT. Bangladesh demographic and health survey 2007. National Institute of Population Research and Training, Maryland, USA, 2009. Saikia P. Bangladesh on the Tipaimukh Dam: A print media analysis. The Daily Star. http://www.thedailystar.net, 2012 February 11. Tariq SM. Implementation of Indus Water Treaty. PLIDAT. Islamabad, Pakistan: Pakistan Institute of Legislative Development and Transparency, 2010. River basins are the natural systems for water resources in Bangladesh. The three rivers (Ganges-Bramhaputra-Meghna) provide 90% of stream flow and 80% of freshwater inflow into the country. Overall, Bangladesh has more than 200 large and small rivers out of which 57 are trans-boundary rivers enter from India. Over 93% of the catchment area of rivers flowing in Bangladesh lies outside the country. Studies found that the volume of water carried during the monsoon (June-October) by these three rivers is the second only to that of Amazon (Gregory, Biswas, & Chowdhury, 2010). Thus, Bangladesh relies on its neighbors, especially India, for the quality and quantity of freshwater for the population (Sood & Mathukumalli, 2011). Bangladesh ground water is contaminated by arsenic due to water diversion from the Ganges and other rivers in addition to seepage of contaminated water from West Bengal (Adel, 2005). 125 mil people living in alluvial plains of Ganges-Bramhaputra-Meghna basin are exposed. Of this, 87 mil are exposed to levels greater than the WHO standard of 0.01 mg/l (Gregory et al 2010). There is a significant risk of hypertension to the presence of inorganic arsenic in drinking water(Adel 2005). Another concern of large dams is earthquake. India is constructing a dam on the Barak river at Tipaimukhpoint. This will not only trap the water flow to the Meghna river, but will expose Bangladesh to a high risk of ecological disaster. Experts opined that the dam area is in an active seismic zone which has experienced more than eight major earthquakes with a magnitude of more than 8 on the Richter scale. Therefore, there is high possibility of severe earthquake causing dam failure and environmental disaster causing unimaginable destruction in the lower Surma-Kushiyara-Maghna basin (Saikia, 2012). Bangladesh and India have agricultural populations that are heavily dependent on river water. Common rivers are critical in the GDPs and cultures of both countries (Soodet al 2011). In Bangladesh, rivers have shaped the physical form of the land, and major changes to the river regime could disturb the delicate balance of life. For instance, if less water flows downstream due to water abstraction and more sediment flows due to upstream floods, is a strong possibility of changing the land shape in Bangladesh gradually and even dramatically (Bhattarai2009). India constructed the Farakka dam in 1975 on the river Ganges about 18 km from Bangladesh boarder where the Ganges enters Bangladesh. The dam reduced 75% of the water flow into the country, causing drastic shortages during dry seasons and sudden water releases during the rainy seasons causing extensive flooding and damaged lives and property (Chen 2000, Adel 2005). Of the 3.6 x1012 m3 of water withdrawal annually by humans worldwide, the single largest withdrawal takes place upstream of Bangladesh – about 3.7 x 1010 m3 annually from the Ganges (Adel 2005). This impacts annual rainfall patterns and increases local temperatures. Frequencies of 100 mm or more rainfall were halved after the diversion. This caused a proportional drop in runoff which was 40% of the rainfall. The water level effectively dropped by 50% in post-Farakka years and rainfall records from 1973 to 1990 show a decrease of over 30% (Adel, 2005). Furthermore, a significant increase in sediment discharge was recorded in the Brahmaputra and Ganges between 1980 and 1991, which was attributed to reduced flow of the Ganges downstream of the Farakka dam (Soodet al 2011). Recently, under the US$200 billion Rivers Interlinking Project (RIP), India plans to unilaterally divert water from the Brahmaputra and Tista to the Ganges by two major links entirely through Indian territory. The problems that the Farakka dam in the Ganges river has caused, highlights concerns by Bangladesh that India has similar plans to withdraw water from the Brahmaputra and Tista rivers as well as the Meghna river (building dam on ‘Sari’ river to the north-eastern of Bangladesh which supplies water to ‘Surma’ river). The diversion of water from the Brahmaputra, which is part of the third largest water resources in the world, and provides 67% of the country’s fresh water flow in the dry season, would cause an ecological disaster for riverine Bangladesh (Bhattarai2009, Rahaman et al 2009). Conclusions Background Global Health & Population Studies, Department of Public Health Sciences, University of Hawaii at Manoa, Honolulu, Hawaii Mohammad MasadulAlamMPH GradCert GHPS & Deon V. Canyon PhD DBA MPH FACTM Indian Damming of Transboundary Rivers and Flow-on Health Concerns in Bangladesh