The Swedish Environmental Epidemiology Center is collecting wastewater samples from cities across Sweden and investigating frequency of variant specific SARS-CoV-2 mutations. Samples from Kalmar, Umeå, Uppsala, Örebro, Stockholm, Malmö wastewater treatment plants were analyzed. PIs: Maja Malmberg (maja.malmberg@slu.se), Anna J. Székely (anna.szekely@slu.se), Zeynep Çetecioğlu Gürol (zeynepcg@kth.se).