Heavy Metals in Suspended Particulate Matter of the Zhujiang River, Southwest China: Contents, Sources, and Health Risks

Jie Zeng,Yang Tang,Qixin Wu,Guilin Han

doi:10.3390/ijerph16101843

Abstract

To investigate the abundance, water/particle interaction behavior, sources, and potential risk of heavy metals in suspended particulate matter (SPM), a total of 22 SPM samples were collected from the Zhujiang River, Southwest China, in July 2014 (wet season). Nine heavy metal(loid)s (V, Cr, Mn, Ni, Cu, Zn, As, Cd and Pb) in SPM were detected. The results show that the selected heavy metal(loid)s in SPM appear in the following order: Mn (982.4 mg kg−1) > Zn (186.8 mg kg−1) > V (143.6 mg kg−1) > Cr (129.1 mg kg−1) > As (116.8 mg kg−1) > Cu (44.1 mg kg−1) > Ni (39.9 mg kg−1) > Pb (38.1 mg kg−1) > Cd (3.8 mg kg−1). Furthermore, both the enrichment factor (EF) and geo-accumulation index (Igeo) indicate that SPM is extremely enriched in metal(loid)s of Cd and As, while SPM is slightly enriched, or not enriched, in other heavy metals. According to the toxic risk index (TRI) and hazard index (HI), arsenic accounts for the majority of the SPM toxicity (TRI = 8, 48.3 ± 10.4%) and causes the primary health risk (HI > 1), and the potential risks of V and Cr are also not negligible. By applying a correlation matrix and principal component analysis (PCA), three principal components (PC) were identified and accounted for 79.19% of the total variance. PC 1 (V, Cr, Mn, Ni, Cu, and Pb) is controlled by natural origins. PC 2 (As and Cd) is mainly contributed by anthropogenic origins in the basin. PC 3 (Zn) can be attributed to mixed sources of natural and anthropogenic origins. Moreover, all the partition coefficients (lgKd) exceeded 2.9 (arithmetical mean value order: Mn > Pb > Cd > V ≈ Cu > Cr ≈ Ni), indicating the powerful adsorptive ability of SPM for these heavy metal(loid)s during water/particle interaction.

Highlights

IntroductionHeavy metals are one of the most significant pollutants in the environment, in the aquatic environment, that may cause severe deterioration of water quality and do harm to living organisms due to their toxicity, persistence, non-biodegradability, and bio-accumulation [1,2,3]
Heavy metals are one of the most significant pollutants in the environment, in the aquatic environment, that may cause severe deterioration of water quality and do harm to living organisms due to their toxicity, persistence, non-biodegradability, and bio-accumulation [1,2,3].Generally, heavy metals in the aquatic system can be divided into three phases: dissolved load, suspended particulate matter (SPM), and sedimentary [4,5,6,7,8]
This study indicates that systematic analyses of data on nine heavy metal(loid)s in SPM samples of the Zhujiang River using multi-indicators/statistical techniques—including partition coefficient, enrichment factor (EF), geo-accumulation index (Igeo ), toxic risk index, hazard index, correlation analysis and principal component analysis—can provide important support regarding the prevention–control of heavy metal pollution, and health risk control in the whole basin

Summary

Introduction

Heavy metals are one of the most significant pollutants in the environment, in the aquatic environment, that may cause severe deterioration of water quality and do harm to living organisms due to their toxicity, persistence, non-biodegradability, and bio-accumulation [1,2,3]. Heavy metals in the aquatic system can be divided into three phases: dissolved load, suspended particulate matter (SPM), and sedimentary [4,5,6,7,8]. The dissolved phase is believed to be more toxic to aquatic organisms and humans, its content is usually lower than the suspended particle phase [9]. Because of the high surface area and reactivity of suspended particulate matter, the dissolved heavy metals are absorbed by SPM [8,10]. Public Health 2019, 16, 1843; doi:10.3390/ijerph16101843 www.mdpi.com/journal/ijerph

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