(45)To ensure the protection of the environment and that adequate action is taken under any risk assessment to be carried out for the implementation of this Directive as well as for the implementation of other Union law, Member States should monitor a broad spectrum of pollutants at the inlets and outlets of the urban wastewater treatment plants. To avoid an unnecessary burden, only pollutants that can be expected to be found in urban wastewater should be monitored, taking into account the high variety of pollutants which could reach urban wastewater treatment plants, including from non-domestic wastewater sources. Member States should be able to reduce the monitoring frequency if pollutants are not found in subsequent sampling campaigns. More specifically, recent data shows that PFAS are found in urban wastewater, sometimes at high concentrations. The most recent scientific evidence shows that PFAS are a concern for the environment and for public health due to their persistence. It is therefore essential to better understand the pathways of PFAS into the environment and to monitor them in the inlet and outlet of the urban wastewater treatment plants. This monitoring should start in the first instance where the discharges reach catchment areas used for the abstraction of drinking water, due to the high risks of being exposed to PFAS and their impact on health.