Discussion

    The slowness of the bactericidal activity in some of the shampoos causes initial pause as to the generalness of recommending the use of these common commercial products for making potable water. However it must be remembered that the newspaper-filtration process takes 30 minutes or longer to produce the first 50 mL. All during that time, the germ-killing activity is on-going. Thus, in reality, there is sufficient time for even the slowest of the shampoos to be effective.

    Thus the four critical criteria have been met. (1) The first is that the process is intuitive and easy to remember. (2) The second is that the materials are extremely low-tech, and readily available in almost any disaster area in the world. Shampoo in its floating, non-breakable containers, newspaper and some sort of support such as baskets or screening are strewn widely to the extent that many set-ups can be made and running simultaneously. (3) The third is that bacterial pathogens are effectively eliminated. Since the vast majority of pathogens are diarrheal, and in the non-spore-forming groups, the method is shown effective. (4) And the fourth is that protozoan and other near-microscope eggs of parasites are also eliminated. This the newsprint filter does with efficiency.

    Unlike solar stills, this apparatus is not dependent upon light or warmth other than its being above freezing. Furthermore, it is much faster than similarly sized solar stills in processing water.