As enteroviruses are mainly transmitted by the fecal-oral route, this study was initiated to investigate the nature of the binding of enteroviruses to human skin. Using poliovirus 1, Mahoney, we investigated the overall effectiveness of soap and water hand-washing of 1 and 5 min duration. The virus-skin interaction was studied by kinetic analysis of repeated serial washings. The following results were obtained: (1) Soap and water washing for 5 min reduced the number of infective particles on hands by 2-4 logs of ten. (2) Poliovirus binding to skin was essentially reversible. (3) Removal of virus followed a triexponential decline curve, suggesting loose, intermediate, and strong binding. (4) Washing agents more effective than soap were sand, aluminum hydroxide powder, and buffer alone, suggesting that friction was more important than emulsification. The results demonstrate the tenacity of poliovirus on skin, and offer a rationale for the epidemiology of enteroviruses on experimental grounds. From a practical point of view these results stress the need for an effective chemical hand disinfectant, particularly in hospitals.