Sunflowers growing in pots were placed, with their roots submerged, in the pond contaminated with radioactive elements. The sunflowers kept growing; in the process, they absorbed radioactive elements. Within twelve days, 85 percent of the radioactive elements were removed from the water, which is no less than can be accomplished with the much more expensive conventional filtration techniques. Scientists ttherefore propose using sunflowers for decontamination wherever there are radioactively contaminated ponds.
The statement 'Some plants other than sunflowers can also remove radioactive elements from water' points to a limitation on the applicability of the proposed method of decontamination.