Current route planners on smart phones or special routing devices try to minimize the traveling time. But many users are no longer interested in the shortest route in time but they prefer a healthier route. In many smart cities there is a centralized distributed network of sensors measuring the pollution in a city on different locations for different time of the day. In this paper we present a routing App computing the less polluted route along the streets using the measurement of the eco sensors. The council of a smart city takes care of the health of their citizens. The developed routing App enables travelers with lung diseases to choose a healthy route. The routing algorithm is based on a special variant of the well-known Ant Based Control routing algorithm. To combine data measuring pollution and shortest traveling time, we solved a special multi-parameter problem. In some experiments we performed a user test of the routing App on different time and location.