Suspended particulate matter-associated environmental corticosteroids in the Pearl River, China: Occurrence, distribution, and partitioning

Jian Gong; Yong-Shun Zhou; Can-Yuan Lin; Qiang Li; Chong Han; Ke-Xin Yang; Ying Huang; Wei-Quan Lin; Cui-Qin Wu; Shu-Han Zhang; Jia-Yu Huang

doi:10.1016/j.scitotenv.2023.163701

Suspended particulate matter-associated environmental corticosteroids in the Pearl River, China: Occurrence, distribution, and partitioning

Sci Total Environ. 2023 Aug 1:884:163701. doi: 10.1016/j.scitotenv.2023.163701. Epub 2023 Apr 25.

Authors

Jian Gong¹, Yong-Shun Zhou², Can-Yuan Lin², Qiang Li³, Chong Han³, Ke-Xin Yang², Ying Huang², Wei-Quan Lin⁴, Cui-Qin Wu², Shu-Han Zhang², Jia-Yu Huang⁴

Affiliations

¹ Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China. Electronic address: jiangong@gzhu.edu.cn.
² Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
³ School of life Sciences, Guangzhou University, Guangzhou 510006，China.
⁴ School of Chemistry and Chemical Engineering, Analytical and Testing Center of Guangzhou University, Guangzhou University, Guangzhou 510006，China.

PMID: 37105482
DOI: 10.1016/j.scitotenv.2023.163701

Abstract

Suspended particulate matter (SPM) plays an important role in the geochemical behavior and fate of organic micropollutants in aquatic environments. However, the presence of trace emerging endocrine disruptors such as environmental corticosteroids (ECs) in SPM is less well understood. This study focused on the occurrence, distribution, and partitioning of SPM-associated ECs in the Pearl River system, China. Ubiquitous particulate ECs were found in the surface water of the rivers at average concentrations (dry weight) between 0.46 ng/g (flumethasone) and 8.83 ng/g (clobetasone butyrate). The total EC (∑ECs) concentrations of the 24 selected target compounds varied from <1.03 ng/g to 62.3 ng/g, with an average and median of 17.6 ng/g and 13.7 ng/g, respectively. Higher SPM-bound EC levels were commonly observed in winter (dry season), and spatially, their relatively high contamination in urban tributary networks decreased while flowing to mainstreams and then gradually attenuated from upstream to the estuary. Despite the approximately 90 % mass distribution of ∑ECs in the aqueous phase, approximately 50 % of their effect burden was derived from the suspended particulate fractions. For the first time, in situ SPM-water partitioning coefficients (K_p) and their organic carbon-normalized ones (K_oc) of ECs were determined in surface waters, and a field-derived preliminary linear equation was proposed to estimate K_oc for ECs using basic physicochemical parameters n-octanol/water partitioning coefficient (K_ow), which is of importance with regard to the assessment of transport, fate, and risk of these emerging hazardous chemicals. Furthermore, the significant logK_oc-logK_ow relationship for ECs reveals that nonspecific hydrophobic partitioning is a major association mechanism between SPM and ECs. Moreover, hydrogen bonding is suggested to be a prevailing specific binding mechanism and provides more contribution to nonhydrophobic interactions between ECs and particulate organic matter than environmental estrogens.

Keywords: Binding mechanism; Corticosteroid; Partitioning; Spatiotemporal distribution; Surface water; Suspended particulate matter.

MeSH terms

Adrenal Cortex Hormones
China
Dust
Environmental Monitoring
Geologic Sediments / chemistry
Particulate Matter / analysis
Rivers* / chemistry
Water
Water Pollutants, Chemical* / analysis

Substances

Water Pollutants, Chemical
Particulate Matter
Adrenal Cortex Hormones
Water
Dust