ABSTRACT
The.high.usage.of.drugs.throughout.the.world,.their.partial.metabolism.after.ingestion,.and. inconsistencies. in. the.way. they.are.disposed.make. their.presence. in. the. aquatic.environment. inevitable..Their.sources. in.natural.waters.are.not. limited. to. excretion.of.parent.compounds.and.their.metabolites.by.individuals.and.pets.but.also. include. disposal. of. unused. medications. to. sewage. systems,. underground. leakage. from.sewage.system.infrastructures,.release.of.treated.or.untreated.hospital.wastes,. disposal.by.pharmacies.and.physicians,.and.humanitarian.drug.surplus.to.domestic. sewage.systems..Transmission.routes.include.release.to.private.septic.fields;.treated. effluent.from.domestic.sewage.treatment.plants.discharged.to.surface.waters;.overflow.of.untreated.sewage.from.storm.events.and.system.failures.directly.to.surface. waters;.transfer.of.sewage.solids.to.land;.release.from.agriculture;.dung.from.medicated.domestic.animals.and.confined.animal.feeding.operations;.direct.release.via. washing,. bathing,. or. swimming;. discharges. from. industrial. manufacturing. and. clandestine.drug.laboratories,.as.well.as.illicit.drug.usage;.leaching.from.defective. landfills;. and. release. from.aquaculture.1.After. release. into. the.environment,.most. pharmaceutically.active.compounds.(PhACs).are.eventually.transported.to.the.aqueous.domain.and.are.expected. to.be.only.partially.degraded.and. transformed. into. other.products.by.phototransformative,.physicochemical,.and.biological.degradation. reactions..The.environmental.fate.of.only.a.fraction.of.these.compounds.has.been. evaluated.in.laboratory.studies,.and.only.recently.has.their.occurrence.in.drinking.
