Table 1.

SARS-CoV-2 RNA detected in untreated wastewater/sludge from WWTPs from various studies.

Sample locations	Sample types	Sample storage/treatment before analysis	Target genes analyzed	Reference
France [Paris]	Wastewater samples from WWTPs.	4 °C; <24 h	RdRp	Wurtzer et al. (2021s)
India [Chennai]	Samples of hospital wastewater (HWW)	Ice cooled	N1, N2	Chakraborty et al. (2021)
India [Ahmedabad]	Treated wastewater samples for receiving water bodies	4 °C	ORF1ab, N and S	Kumar et al. (2021)
Israel (different Cites]	Wastewater in its raw state from various WWTPs	−80 °C or − 20 °C	E	Bar-Or et al. (2021)
Italy [Milan and Monza]	Effluent from three WWTPs and receiving rivers, both raw and treated	No information	ORF1ab, N, E	Rimoldi et al. (2020)
Italy [Milan and Rome]	Raw wastewater from three WWTPs	−20 °C	ORF1ab, S	La Rosa et al. (2020)
Japan [Yamanashi]	Wastewater from a single WWTP that was treated	Ice; <6 h	N1, N2	Haramoto et al. (2020)
Netherlands [ Different Cities]	Raw samples from WWTPs in five cities and one airport	Melting ice; <24 h	N1, N2, N3, E	Medema et al. (2020a), b
Southeastern Queensland (Australia)	Raw wastewater from a pumping station and two WWTPs	−80 °C; <24 h	N	Ahmed et al. (2020a)
Spain [Murcia]	Sewage from six WWTPs, both raw and treated	4 °C; <24 h	N1, N2, N3	Randazzo et al. (2020)
USA [Massachusetts]	Raw wastewater from a single WWTP	4 °C/30min@90 °C	N1, N2, N3	Wu et al. (2021)
USA [New Haven, Connecticut]	Primary sewage sludge from a single WWTP	−80 °C	N1, N2	Peccia et al. (2020)
Spain [Ourense in north-western Spain]	Raw wastewater and sewage sludge from a single WWTP	4 °C; <24 h	E, N, ORF1ab, RdRP and S	Balboa et al. (2021)
Turkey [Istanbul]	Primary sludge and waste activated sludge from different WWTPs	No information	RdRp	Kocamemi et al. (2020)
Ottawa [Canada]	Primary sludge from different WWTPs	4 °C; <24 h	N1, N2	D'Aoust et al. (2021)