Proceedings of a Symposium: Arsenic - The Geography of a Global problem
One of the principal outputs of the study was a symposium to present up-to-date perspectives on arsenic pollution around the world. The symposium was held on 29th August 2007 at the Royal Geographical Society (RGS) in London, as part of the RGS Annual International Conference. The symposium was initially organised around four themes, which the basis for the first four sessions:
- Extent, severity and nature of Arsenic contamination
- Inter-relationships of Arsenic, Soil, Food, Water and Health
- Hydrochemistry and management of groundwater
- Mitigation and sustainability of water supply in Arsenic-affected areas
- Short contributions and discussion
However, such was the interest in the meeting that a fifth session was added in the evening to accommodate a series of short presentations on various topics, and an extended discussion of many of the issues raised during the technical sessions. The first two sessions were kindly chaired by Professor Sir Gordon Conway, President of the RGS, and an adviser to Department for International Development (DFID).
The first session was opened by Richard Wilson (Harvard) who gave an overview of the nature and consequences of arsenic pollution, the effectiveness of some of the approaches to mitigation, and the roles played by the various actors who influence their outcomes. Peter Ravenscroft (Cambridge) University gave an update of present knowledge on the geographical extent of arsenic pollution, analysed its environmental associations, and made predictions where arsenic will, and will not, be found in the future. Next, Johanna Buschmann of the EAWAG institute in Switzerland presented an account of arsenic contamination along the Mekong River in Cambodia, explaining how it is relate to local topography. Allan Smith (Berkeley) presented an important update on his group's previous investigations in Chile and West Bengal, emphasising three main conclusions: that the impacts of arsenic on the lungs is much greater than previously recognised; that that exposure in utero and in early childhood causes serious lung disease in adult life; and that cancer risks associated with arsenic at the (old, 50 ppb) drinking water standard are a hundred times worse than for any other water contaminant. On a quite different theme, Peter Atkins (Durham) discussed some the ethical and legal issues associated with environmental justice and arsenic pollution, illustrating this by reference to the notorious BGS case.
Session 2 focussed the interrelationships between arsenic water, soil and food. Andy Meharg (Aberdeen) examined the occurrence and factors that affect the accumulation of arsenic in rice in Bangladesh and rice bought in markets in the UK. Hugh Brammer (ex-FAO) took a broader view of arsenic and rice production, focusing on paddy soils, and the possibility of modifying farming practices to reduce arsenic exposure. Conversely Debapriya Mondal (Manchester) considered the human health risks arising from rice consumption in West Bengal, while V. Devesa (Valencia, Spain) examined the consequences of combined exposure to arsenic from food and water in Northern Argentina. Farhana Sultana (Kings, London) completed the session by demonstrating how gender and class interact to determine the outcome of arsenic exposure in Bangladesh.
In Session 3, attention switched to the geochemistry and hydrogeology of arsenic in groundwater. John McArthur (UCL, London) gave a provocative talk on 'simplicity and complexity' to demonstrate an emerging picture of predictability of arsenic in groundwater, where arsenic intimately linked to the occurrence of iron oxides and iron sulphides. This was followed by four case histories of arsenic occurrence in diverse parts of the world. Jiin-Shuh Jean (Cheng Kung, Taiwan) described the endemic blackfoot-disease area of southwest Taiwan; Ondra Sracek (Prague) described arsenic beneath the Chaco-Pampean Plain of northwest Argentina; Ashok Ghosh (A. N. College, India) presented information arsenic along the Ganga Plains of Bihar; and Willy Burgess (UCL, London) explained ongoing work to assess the risks that arsenic poses to the deep aquifers of Southern Bangladesh.
As a natural follow-up to the earlier presentations, Session 4 turned to experiences of attempts to mitigate arsenic polluted supplies. Bases on experience in Bangladesh, Guy Howard (DFID) elaborated holistic approaches to safe water supply in arsenic affected areas, and also stressed the importance integrating water supply actions with water resources strategies. Meera Hira-Smith (Berkeley) described water quality surveillance and experience with developing safe dug wells in West Bengal. Also from West Bengal, Sudhansu Sinha (ICEF) presented ICEF's experiences with rural supply schemes. Following on the theme introduced by Howard, George Adamson (Manchester) explained the methodology and presented the results of a risk assessment of arsenic mitigation in Bangladesh. In the final talk, Kazi Matin Ahmed (Dhaka) set out the technical and managerial requirements for the continued use of the Deep Aquifer in Bangladesh as a source of safe water supply.
Session 5 included an overview of the arsenic contamination in China by Yan Zheng (Columbia), followed by short presentations on the geochemistry of aquifers in Bengal (Nath, Taiwan); vulnerability in Bihar (Bose, A N College); health impacts and the work of Dhaka Community Hospital in Bangladesh (Rahman, DCH); and the latest mapping of arsenic in India (Nickson, UNICEF).
Editorial Note. Many of the presentations contained animation, sound or other special effects that are not reproduced here. Interested persons may contact the authors directly.