Azolla filiculoides Lam. and A-pinnata R. Brown to measure arsenic pollution in groundwater

Effects of arsenic on the growth and pigmentation of Azolla filiculoides Dh 115 and A. pinnata var, pinnata Dh113 were studied under controlled growth room conditions with the aim of measuring arsenic in contaminated water. A. filiculoides Dh115 became rosy to blood-red while A. pin,tata var, pinnata Dh113 became golden-brown coloured after certain period of growth in prese nce of arsenic. A. filiculoides Dh115 particularly, showed distinct changes in colour depending on the concentrations of arsenic in the defined inorga nic medium. Arsenic contaminated hand-tube well water also caused red colou ration in leaves. The characteristic red colour of the A. filiculoides Dh11 5 could be used in the identification and measurement of arsenic in water b y matching with the standard series. The amount of anthocyanin synthesized (causing red colour) per unit quantity of the A. filiculoides Dh115 biomass vary with arsenic concentration This biochemical analysis method could be also used in the precise measurement of arsenic in the groundwater comparin g with the standard series. Three to six day incubations would be needed fo r complete manifestation of characters depending on the light and temperatu re regimes. The A. filiculoides Dh115. thus could be effectively used in me asuring arsenic concentration in groundwater samples.