Table 1. Concentrations of the Different Types of Micro/Nanoplastics Observed in the Surface Snow and Snowpit Samples^a.

	melted snow			filtered snow (0.2 μm)
sample	match	score	quantity [ng/mL]	match	score	quantity [ng/mL]
snowpit 2017, depth of 2.6 m	PET	61.5	7.0
	PPC	64.4	16.5
snowpit 2017, depth of 2.8 m	PET	65.8 ± 3.1	22.9 ± 13.9	PET	65.6 ± 7.7	18.5 ± 1.5
snowpit 2017, depth of 3.0 m	PET	78.2 ± 14.2	5.6 ± 0.9
	PPC	60.9 ± 2.4	10.8 ± 4.1
	PVC	62.6 ± 5.4	6.9 ± 0.2
surface snow 2017-03-20	n/a		n/a	PET	81.4 ± 7.1	4.6 ± 0.9
surface snow 2017-03-23	n/a		n/a	PET	60.4 ± 9.7	18.5 ± 2.2
surface snow 2017-03-26	n/a		n/a	PET?	57.1 ± 1.5	23.6 ± 3.0
surface snow 2017-03-29	n/a		n/a	PET	70.0 ± 1.7	12.1 ± 2.3
surface snow 2017-04-01	n/a		n/a	PET	62.7 ± 2.5	13.8 ± 2.3

^aNot corrected with an underestimation factor of ∼6.7 (see Materials and Methods). Errors represent standard deviation over the triplicate of all filtered samples and duplicates for melted snow samples, except the pit sample 2.6 M (single run). All the match scores can be found in the Supporting Information.