In India, high concentrations of both organochlorine and organophosphorous pesticides have been found in surface and ground water samples. Reverse-osmosis water filters are expected to remove pesticide residues. We tested the 10 brands for pesticide residues. They were all able to reduce the pesticide residues and scored equally well. FOR TOXIC METALS/MATERIALS
The Bureau of Indian Standards (BIS) has specified requirements for removal/reduction of heavy metals in IS:16240. We tested the 10 brands for presence of the following heavy metals:
Arsenic: As many as six brands – Tata Swach, Zero B, Kent, Aquaguard, Electrolux and Usha – did not meet the requirement (a maximum 0.01 mg/l). Copper: None of the brands met the requirement set by Indian Standard (0.05 mg/l).
Mercury: All the brands more or less met the specified requirement – minor deviations were observed in Pureit, Aquaguard and Usha.
Cadmium: Minor deviation was observed in one brand, Pureit. All other brands met the standard requirement.
Iron: All the brands met the requirements, with the exception of deviation in two brands, Whirlpool and Usha. requirements. Brand LG Whirlpool AO Smith Usha Aquaguard Electrolux Pureit Kent Zero B Tata Swach