PUROH is a tool that can be very useful for reducing the severity of contagions and respiratory conditions in children. Respiratory syncytial virus infections affect 95% of children under two years of age and in some cases can cause lung infections. Children with asthma can see their crises not improve in environments with urban or industrial pollution. PUROH is a device based on the well-known natural Open-Air Factor that prevents and reduces the frequency of contagion episodes by reducing the viral and bacterial load of their environment.