In 1997, arsenicosis was reported as a result of ingesting arsenic-containing rice grown in arsenic (As)-rich soil, irrigated with high As water from shallow tube wells (STW) and deep tube wells (DTW) in Bangladesh. Of the 4 million ha irrigated fields, 60% were under STW and 15% under DTW waters; almost all were arsenic contaminated in varying quantities since they were used. In the present study, it was determined that irrigation from STW water having 500 µg As/l produced rice grains with 2.56 mg As/kg in a field with initial 3.21 mg/kg soil, leaving 8.27 mg/kg soil compared to pond water irrigation where only roots absorbed 0.105 ± 0.069 mg As/kg leaving ≤2.6 mg/kg soil. About 2.5 mg As/kg soil may be considered a safe level for arsenic-free rice cultivation. Bio-mitigation of the STW water using duckweed (DW) (Spirodela polyrhiza) was expensive and disposal in various ways of As-loaded DW produced was hazardous returning arsenic to ecosystems. Alternative to the groundwater (GW), surface water can be made available by constructing rubber dams and converting rivers into surface water reservoirs to overcome the arsenic toxicity and protecting rice and other grains, integrating aquaculture of the DW and Azolla pinnata var. pinnata for fish and poultry feeds. Permanent solution could be achieved executing “Delta Plan 2100” saying “No to groundwater use for irrigation, let the Arsenic stay in the underground”.
Part of the book: Protecting Rice Grains in the Post-Genomic Era