Microplastics and trace metals in river sediment: Prevalence and correlation with multiple factors

Thi Lan Huong Nguyen; Thi Lim Duong; Thi Huong Thuy Nguyen; Tran Quan Dang; Thi Hue Nguyen; Ngoc Nhiem Dao; Kien Trung Nguyen; Cong Dien Duong; Ngo Nghia Pham; Bac Quang Nguyen

doi:10.1016/j.scitotenv.2023.165145

Microplastics and trace metals in river sediment: Prevalence and correlation with multiple factors

Sci Total Environ. 2023 Oct 15:895:165145. doi: 10.1016/j.scitotenv.2023.165145. Epub 2023 Jun 28.

Affiliations

¹ Institute of Geography, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Viet Nam.
² Graduate University of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Viet Nam; Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Viet Nam.
³ Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Viet Nam.
⁴ Institute of Mechanics, Vietnam Academy of Science and Technology, 264 Doi Can, Ba Dinh, Hanoi 100000, Viet Nam.
⁵ Faculty of Chemistry, VNU University of Science, 19 Le Thanh Tong, Hoan Kiem, Hanoi 100000, Viet Nam.
⁶ Graduate University of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Viet Nam; Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Viet Nam. Electronic address: quangbac1993@gmail.com.

PMID: 37385491
DOI: 10.1016/j.scitotenv.2023.165145

Abstract

Microplastics (MPs), which are ubiquitous, are no longer novel emerging pollutants, yet our knowledge of them is insufficient. This study investigates the prevalence of MPs and trace metals in sediment belonging to Ma River, Vietnam, and their interaction with various parameters, including nutrients such as total carbon (TC), total nitrogen (TN), and total phosphorus (TP), grain sizes, and MPs in surface water. The study revealed that the abundance of MPs in sediment (MPs/S) is relatively high (i.e., 1328.3 ± 1925.5 items.kg^-1 dry weight), while the concentration of MPs in surface water (MPs/W) was relatively low (i.e., 57.3 ± 55.8 items.m^-3) compared to other areas. Notably, the study found that arsenic and cadmium concentrations exceeded baseline levels, indicating their anthropogenic origin. To interpret the relationship between MPs/S, metals, and the aforementioned parameters, principal component analysis and Pearson correlation analyses were employed. The results demonstrated a significant correlation between metals and nutrients, as well as small grain sizes such as clay and silt. It was observed that the majority of metals displayed co-occurrence with one another but showed weak associations with the levels of MPs present in both water and sediment. Additionally, a weak correlation was observed between MPs/W and MPs/S. In conclusion, these findings suggest that the distribution and behavior of MPs and trace metals in aquatic systems are influenced by multiple factors, including nutrient levels, grain size, and other chemical and physical characteristics of the environment. While certain metals may have natural sources, others may result from human activities such as mining, industrial discharge, and wastewater treatment plants. As a result, understanding the sources and aspects of metal contamination are critical for determining their relationship with MPs and developing effective strategies for mitigating their impact on aquatic ecosystems.

Keywords: Microplastics; Nutrient; Sediment; Trace metals; Vietnam.