Table 1.

Overview of individual and accumulated scores^a of papers reporting microplastic concentrations in surface water and drinking water.

Author	Type	Sampling methods	Sample size	Sample processing and storage	Lab preparation	Clean air conditions	Negative controls	Positive controls	Sample treatment	Polymer ID	Total Accumulated Scoreb (TAS, max = 18)
Mason et al. (2018)	Bottle	1	2	2	1	2	2	1	2	1	14
Schymanski et al. (2018)	Bottle	1	1	2	2	2	2	0	2	2	14
Oβmann et al. (2018)	Bottle	1	1	2	2	2	2	0	2	1	13
Mintenig et al., 2019a, Mintenig et al., 2019b	Tap	2	2	2	2	1	2	0	2	2	15
Kosuth et al. (2018)	Tap	0	0	0	2	2	2	0	2	0	8
Mintenig et al., 2019a, Mintenig et al., 2019b	DWTP	2	1	2	2	1	2	0	2	2	14
Pivokonsky et al. (2018)	DWTP	1	1	2	1	1	2	0	1	2	11
Mintenig et al., 2019a, Mintenig et al., 2019b	Ground	2	1	2	2	1	2	0	2	2	14
Wang et al. (2018)	Surface	2	1	1	2	2	2	2	2	1	15
Hendrickson et al. (2018)	Surface	2	1	2	1	1	1	1	1	1	11
Di and Wang (2018)	Surface	2	0	2	2	0	0	1	2	1	10
Mani et al. (2015)	Surface	2	2	1	1	1	1	0	1	1	10
Wang et al. (2017)	Surface	1	0	1	2	1	2	0	2	1	10
Baldwin et al. (2016)	Surface	2	1	1	1	1	2	0	1	0	9
Cable et al. (2017)	Surface	2	1	1	1	1	1	0	1	1	9
Dris et al. (2018a)	Surface	2	2	0	1	1	1	0	1	1	9
Lares et al. (2018)	Surface	1	0	1	2	1	2	0	1	1	9
Rodrigues et al. (2018)	Surface	2	2	1	1	0	1	0	1	1	9
Su et al. (2016)	Surface	2	1	1	1	1	1	0	1	1	9
Zhang et al. (2017)	Surface	2	1	1	1	2	0	0	0	2	9
Dris et al. (2015)	Surface	2	1	2	1	1	1	0	0	0	8
Estahbanati and Fahrenfeld (2016)	Surface	2	2	1	0	0	1	1	1	0	8
Hoellein et al. (2017)	Surface	2	1	2	0	0	1	0	1	1	8
Mason et al. (2016b)	Surface	2	1	1	0	0	2	0	1	1	8
Sighicelli et al. (2018)	Surface	2	2	1	0	0	0	0	2	1	8
Vermaire et al. (2017)	Surface	2	1	2	0	0	2	0	1	0	8
Xiong et al. (2018)	Surface	2	1	0	1	1	1	0	1	1	8
Anderson et al. (2017)	Surface	2	1	1	0	0	1	0	1	1	7
Faure et al. (2015)	Surface	1	2	1	1	0	0	0	1	1	7
McCormick et al. (2016)	Surface	1	1	1	0	0	2	0	1	1	7
Miller et al. (2017)	Surface	1	0	1	1	1	2	0	0	1	7
McCormick et al. (2014)	Surface	1	1	1	0	0	2	0	1	0	6
Fischer et al. (2016)	Surface	2	1	1	0	0	0	0	1	0	5
Free et al. (2014)	Surface	2	1	1	0	0	0	0	1	0	5
Lahens et al. (2018)	Surface	1	1	1	0	0	0	0	1	1	5
Leslie et al. (2017)	Surface	1	0	2	0	1	1	0	0	0	5
Eriksen et al. (2013)	Surface	2	1	1	0	0	0	0	0	0	4
Zhang et al. (2015)	Surface	2	1	0	0	0	0	0	0	1	4
Mintenig et al. (2017)	WWTP	2	2	2	1	1	2	0	1	2	13
Ziajahromi et al. (2017)	WWTP	2	2	1	1	1	1	1	1	2	12
Simon et al. (2018)	WWTP	1	1	0	1	1	2	2	2	1	11
Lares et al. (2018)	WWTP	2	0	1	2	1	2	0	1	1	10
Talvitie et al. (2017a)	WWTP	2	1	1	1	1	2	0	0	2	10
Murphy et al. (2016)	WWTP	1	1	2	2	1	1	0	0	1	9
Mason et al. (2016a)	WWTP	2	2	1	0	0	2	0	1	0	8
Vollertsen and Hansen (2017)	WWTP	0	2	1	0	0	0	2	1	1	7
Carr et al. (2016)	WWTP	2	2	1	0	0	0	0	0	1	6
Magnusson and Norén (2014)	WWTP	2	2	1	0	0	0	0	0	1	6
Michielssen et al. (2016)	WWTP	2	1	2	0	0	1	0	0	0	6
Talvitie et al. (2017b)	WWTP	2	0	1	0	0	2	0	0	1	6
Vermaire et al. (2017)	WWTP	1	0	2	0	0	2	0	1	0	6
Dyachenko et al. (2017)	WWTP	1	0	1	0	0	0	1	1	1	5
Leslie et al. (2017)	WWTP	1	0	2	0	1	1	0	0	0	5
Dris et al. (2015)	WWTP	1	0	0	1	1	1	0	0	0	4
Talvitie et al. (2015)	WWTP	2	1	0	0	0	1	0	0	0	4
Browne et al. (2011)	WWTP	0	0	1	0	0	0	0	0	2	3
Average		1.57	1.02	1.20	0.77	0.64	1.18	0.21	0.93	0.89	8.41

^aFor the scoring criteria, the reader is referred to Table S2.

^bTAS values are underlined when all underlying scores are non-zero.