In particular, how many drugs are we taking into our body when we drink municipal water?
According to recent research environmental pollution by pharmaceuticals is increasingly recognized as a major threat to aquatic ecosystems worldwide. A variety of pharmaceuticals enter waterways by way of treated wastewater effluents and remain biochemically active in aquatic systems.
A recent study  looked at the altered behaviour of perch when exposed to oxazepan, a tranquilizing drug used to treat anxiety and insomnia and alcohol withdrawal, at levels often found in surface water. They noted