Table 3. Contents of microplastics detected in saline water-based solutions immersed plastic and wooden shelters for 6 weeks

	Solution type	PE	PP	EVA	Polyester	PU	Total
1^st day	Tap water	4	7	1	-	-	12
1^st day	Solar salt	48	19	-	30	-	97
2^nd week	Plastic shelter	6	1	1	14	3	25
2^nd week	Wooden shelter	1			7	1	9
4^th week	Plastic shelter	1	9	1	4	-	15
4^th week	Wooden shelter	3	-	-	3	2	8
6^th week	Plastic shelter	34	10	7	1	-	52
6^th week	Wooden shelter	8	2	-	3	-	13

PE: polyethylene, PP: polypropylene, EVA: ethylene-vinyl acetate copolymer, Polyester: polyethylene terephthalate, polybutylene terephthalate, and others, PU: polyurethane.