Microplastics contamination and characteristics of agricultural groundwater in Haean Basin of Korea

Jihye Cha; Jin-Yong Lee; Rogers Wainkwa Chia

doi:10.1016/j.scitotenv.2022.161027

Microplastics contamination and characteristics of agricultural groundwater in Haean Basin of Korea

Sci Total Environ. 2023 Mar 15:864:161027. doi: 10.1016/j.scitotenv.2022.161027. Epub 2022 Dec 19.

Authors

Jihye Cha¹, Jin-Yong Lee², Rogers Wainkwa Chia³

Affiliations

¹ Department of Geology, Kangwon National University, Chuncheon 24341, Republic of Korea; Research on Microplastics in Groundwater (RMPG), Kangwon National University, Chuncheon 24341, Republic of Korea.
² Department of Geology, Kangwon National University, Chuncheon 24341, Republic of Korea; Research on Microplastics in Groundwater (RMPG), Kangwon National University, Chuncheon 24341, Republic of Korea. Electronic address: hydrolee@kangwon.ac.kr.
³ Department of Geology, Kangwon National University, Chuncheon 24341, Republic of Korea; Research Institute for Earth Resources, Kangwon National University, Chuncheon 24341, Republic of Korea.

PMID: 36549528
DOI: 10.1016/j.scitotenv.2022.161027

Abstract

The quality of groundwater is critical to human health. MPs have access to groundwater from the soil, polluted by various agricultural activities. However, to date, there have been no studies on the occurrence of MP in groundwater from an agriculture field without any adjacent sources of contamination, such as nearby landfills. In this study, the occurrence and distribution of MPs in groundwater of an agricultural area in the Haean Basin, Korea, without any definite source of pollution, was examined. MP and groundwater samplings were conducted in the dry season in 2020, the wet and dry seasons in 2021, respectively. In this study, the reliability of MP analysis was improved through good practices from laboratory to field campaigns, collecting large groundwater samples (300-500 L) volumes. Any involvement of plastic materials was avoided during the full procedures as possible and. Detailed investigation was conducted for the distribution of potential plastics sources like mulching, plastic covers, dripping pipes and shading nets, and hydrogeological properties affecting MPs occurrence. Groundwater MP concentrations of 0.02-0.15 particles/L (median = 0.06 particles/L), 0.02-2.56 particles/L (median = 0.43 particles/L) and 0.20-3.48 particles/L (median = 0.83 particles/L) were found in three rounds of sampling that comprised of the exploratory investigation in 2020, the wet season, and the dry season in 2021, respectively. The identified polymer types were polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS) and polyamide (PA). The MPs concentrations showed no statistically significant seasonal variation but revealed an apparent strong positive correlation (r = 0.71) of MPs with the amount of groundwater use. Findings of this study need more clarification from repeated samplings for multiple years. This study reveals the occurrence of MPs in groundwater in Korea for the first time to the best of our knowledge.

Keywords: Agricultural irrigation; Fertilizers; Groundwater; Haean Basin; Microplastics.