HC Deb 12 March 1990 vol 169 c104W
Mr. Kirkhope

To ask the Secretary of State for the Environment what harmful bacteria have been identified as generally present in a carbon water filter.

Mr. Heathcoat-Amory

Carbon filters absorb organic matter present in water and also promote the decomposition of chlorine. Therefore, a carbon filter can support the development of a wide range of bacteria by providing nutrients for growth and by protecting bacteria from the disinfectant action of chlorine.

The following potentially harmful species of bacteria have been detected in carbon water filters: Pseudomonas Aeruginosa, Aeromonas Hydrophilla, Klebsiella.

These species are all known to be opportunistic pathogens and as such as potentially harmful to the very young, the elderly and immuno-compromised patients.