List of Contributors. 1. Kurt J. Irgolic 1938 - 1999 (W. Goessler). Occurrence and Exposure. 2. Arsenic: the "King of Poisons" in antiquity - a possible threat to future sustainability (I. Thornton). 3. International perspective on naturally-occurring arsenic problems in groundwater (P.L. Smedley et al.). 4. Characterization of arsenic bearing sediments in Gangetic Delta of West Bengal, India (D. Chakraborti et al.). 5. Geochemical and palaeohydrological controls on pollution of groundwater by arsenic (P. Ravenscroft, J.M. McArthur, B.A. Hoque). 6. Progress on research of endemic arsenism in China: population at risk, intervention actions, and related scientific issues (Guifan Sun et al.). 7. Arsenic in Latin America: occurrence, exposure, health effects and remediation (A.M. Sancha, M.L. Castro). 8. Impacts of historic arsenical pesticide use on residential soils in Denver, Colorado (D.J. Folkes, R.A. Litle). 9. Arsenic speciation in fresh-water fish and bivalves (I. Koch et al.). 10. Determination of organoarsenic compounds in finishing chicken feed and chicken litter by HPLC-ICP-MS (W. Pavkov, W. Goessler). Health Effects Epidemiology. 11. Individual susceptibility to arseniasis (Chien-Jen Chen et al.). 12. Bayesian model averaging with applications to the risk assessment for arsenic in drinking water (K.H. Morales et al.). 13. Epidemiological study on various non carcinomatous manifestations of chronic arsenic toxicity in a district of West Bengal (D.N. Guha Mazumder et al.). 14. Possible effects of arsenic on visual perception and visual-motor integration of children in Thailand (U. Siripitayakunkit, S. Lue, C. Choprapawan). 15. Interactions between arsenic and other factors in relation to carcinogenicity (I. Hertz-Picciotto). 16. Arsenic in drinking groundwater from Transylvania, Romania: an overview (E.S. Gurzau, A.E. Gurzau). 17. Preliminary analysis of lung cancer incidence in arsenic exposed population (V. Bencko, J. Rames, M. G tzl). 18. Arsenic ingestion and health effects in Bangladesh: epidemiological observations (M. Rahman, O. Axelson). 19. Occurrence of cancer in arsenic contaminated area, Ronpibool District, Nakorn Srithmmarat Province, Thailand (C. Choprapawon, Y. Porapakkham).