Currently 20 percent of US water consumption is supplied by groundwater, and its contamination is causing considerable alarm. In densely populated Central Pierce County (Wash.), groundwater contamination was found to originate from septic tank drainfields. The highest nitrate and coliform concentrations in groundwater occur when infiltrating rainfall dissolves and leaches these contaminants downward.
This report summarizes an earlier short-term evaluation of a fast food restaurant manager training program and presents result from a re-evaluation approximately 1 year later. Thirty-one establishments in a single corporation were evaluated using criteria from the USPHS Food Service Sanitation Manual. Only 12 of the 31 original managers were still with the corporation 18 months after the start of the project. Those managers who participated in the training program tended to maintain or increase the sanitary quality in their establishments when compared with the short-term effects of training. The sanitary quality of the establishments with new managers that had joined the corporation after the training sessions were completed usually reverted to a quality similar to that before the start of the project which was generally unsatisfactory.
Three types of filters, silver, polycarbonate, and cellulose, were evaluated for permeability toward poliovirus suspended in water, salt-containing, and proteinaceous solvents. The ability of virus to pass through cellulose filters depended on the suspending medium; virus did not pass through cellulose filters in either water or salt solution, whereas the use of protein solutions increased filterability. The virus permeability of both the silver and polycarbonate filters was independent of the suspending medium. Apparently, pore size alone determined their permeability toward poliovirus, and electrostatic forces between filters and the particles being filtered did not appear to play a significant role. Both the silver and polycarbonate filters appear to be promising tools for the separation of viruses from contaminating bacteria and fungi.
Three types of filters, silver, polycarbonate, and cellulose, were evaluated for permeability toward poliovirus suspended in water, salt-containing, and proteinaceous solvents. The ability of virus to pass through cellulose filters depended on the suspending medium; virus did not pass through cellulose filters in either water or salt solution, whereas the use of protein solutions increased filterability. The virus permeability of both the silver and polycarbonate filters was independent of the suspending medium. Apparently, pore size alone determined their permeability toward poliovirus, and electrostatic forces between filters and the particles being filtered did not appear to play a significant role. Both the silver and polycarbonate filters appear to be promising tools for the separation of viruses from contaminating bacteria and fungi.
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