Among emerging pollutants found in surface and ground waters, pharmaceuticals are currently receiving a particular interest. There are several physico/chemical parameters that could describe the fate of pharmaceuticals in the environment, so as their toxicity for ecosystems and human health. The idea is to create an integrated parameter that would relate of the relative influence of these physico/chemical characteristics. Potential impact of pharmaceuticals on the environment could be then ranked using this parameter. Different methods will be tested for ranking (weighted average, mathematical distance functions from the no effect point, ELECTRE, etc). The weights were evaluated in order not to support only a scientific point of view, but also economical and social considerations. For this concern, cooperation with scientists from various fields so as human health managers was carried out. The different methods will be finally compared together so as with previous ranking published in literature. The goal here is not to impose a relative importance of the parameters we integrate, but to introduce the concept of the relative influence for environmental parameters when we deal with water quality problems that could affect ecological systems and human health.