Wastewater surveillance to assess cocaine and methylenedioxymethamphetamine use trends during a major music festival in Brazil. - Gomes CS; de Jesus Soares Freire D; de Souza Ramos Pontes Moura H; Maldaner AO; Pinheiro FASD; Ferreira GLR; de Oliveira Miranda ML; Ferreira LS; Murga FG; Sodré FF; Aragão CFS (Drug testing and analysis, 2025)