Concentrations, Possible Sources and Health Risk of Heavy Metals in Multi-Media Environment of the Songhua River, China

Abstract

Heavy metal pollution in the river environment has been a source of widespread interest due to potential threats to human health and ecosystem security. Many studies have looked at heavy metal pollution in the context of single source-pathway-receptor relationships, however few have sought to understand pollution from a more wholistic multi-media perspective. To investigate potential risks in a more wholistic way, concentrations of six heavy metals (Cd, Cr, Ni, Cu, Zn and Pb) were detected in multi-media (water, sediment and riparian soil) collected from 14 sampling sites in the main stream of the Songhua River. Chemical analyses indicated that the average concentration of heavy metals in water followed: Zn > Cr > Cu > Pb > Ni > Cd, with a different trend observed in sediments and riparian soil: Zn > Cr > Ni > Pb > Cu > Cd. The potential risk was evaluated using the heavy metal pollution index (HPI), Nemerow pollution index (P N ), hazard index (HI) and carcinogenic risk (CR) metrics. Results showed that all HPI values were lower than the critical level of 100 indicating that the levels of these targeted heavy metals were within drinking water safety limits. The P N indicated that both sediment (2.64) and soil (2.95) could be considered "moderately polluted", with Cd and Zn providing the most significant contributions. A human health risk assessment suggested that the non-carcinogenic risks were within acceptable levels (HI < 1), as was the cancer risk associated with dermal adsorption (CR <10 −6 ). However, the CR associated with ingestion exposure (4.58 × 10 −6 ) exceeded the cancer risk threshold (10 −6 ) indicative of elevated cancer incidence in exposed populations. Health-risk estimates were primarily associated with Cd in the Songhua River. Source apportionment was informed by Pearson correlation analysis coupled with principal component analysis (PCA) which indicated that Cu was mainly derived from natural (geogenic) sources; Cr and Ni were associated with industrial emissions; Pb might be derived from agricultural and transportation sources; Zn might be from industrial, agricultural activities and transportation; while Cd is likely from industrial and agricultural emissions. The source apportionment information could provide the basis for a risk-management strategy focused on reducing Cd and Zn emissions to the riverine environment. Results from this study will provide the scientific knowledge that is needed for measuring and controlling heavy metals sources and pollution characteristics, and identifying the potential cancer risk with different exposure pathways, as well as making effective environmental management policies at catchment or regional scales.

Heavy metal contamination and ecological risk in sediment from typical suburban rivers

“…The concentration of Cr was significantly higher than that found in the Majiagou River ( p < .05) (Cui, Zhang, et al, 2019), which flows through the central area of Harbin City and has a relatively long history of receiving inputs/discharges of a large range of pollutants, while the concentrations of Cu and Ni were significantly lower ( p < .05). The concentrations of Cr and Ni were significantly lower than those in the Songhua River (Li et al, 2020) ( p < .01), while the concentrations of Cu and Zn were significantly higher ( p < .05). Considering that these three rivers are secondary tributaries of the Songhua River, the elevated levels of Cu and Zn may pose a negative effect on the water quality and the resident health because the Songhua River is an important source of drinking and irrigation water (Li et al, 2020).…”

“…The concentrations of Cr and Ni were significantly lower than those in the Songhua River (Li et al, 2020) ( p < .01), while the concentrations of Cu and Zn were significantly higher ( p < .05). Considering that these three rivers are secondary tributaries of the Songhua River, the elevated levels of Cu and Zn may pose a negative effect on the water quality and the resident health because the Songhua River is an important source of drinking and irrigation water (Li et al, 2020). However, the concentrations of heavy metals were significantly lower than those in the Pearl River (except for Zn) ( p < .01), which is located in one of the most developed areas of China (Zhang, Bai, et al, 2017).…”

“…PC1 had the highest cumulative contribution rate, accounting for 41.40% of the total variance, including Pb and Zn (consistent with Pearson's correlation analysis; Figure S1). Pb and Zn are likely from domestic garbage, solid waste and the application of pesticides and fertilizers, as well as automobile tires, brake pads and additives for vehicle lubricants, which can cause Pb and Zn to enter the aquatic environment via soil runoff or atmospheric deposition (Bressi et al, 2014; Li et al, 2020; Wuana & Okieimen, 2011). Thus, PC1 can be considered a comprehensive source, including domestic, agricultural and traffic sources.…”

Health Risk and Water Quality Assessment of Surface Water in an Urban River of Bangladesh

“…The health risk assessment for two population groups (adults and children) were done base on their body weight and exposure time. Increasing developmental and industrial activities along the river were identified as the cause of this pollution which was making the water unsuitable for use [18][19][20][21]. To the best of our knowledge, there has been no study conducted yet to investigate the water physicochemical parameters and heavy metal pollution from upstream to downstream of the river.…”

Emergy evaluation of human health losses for water environmental pollution

“…After continuous improvement by the U.S. EPA and other agencies, the four-step evaluation method has developed into a human health risk assessment model (HHRA) (US National Research Council, 1983), which has been widely accepted. It has been used to evaluate the human health risks of drinking water (Pérez et al, 2019;Kujlu et al, 2020), surface water (Zhang et al, 2015;Zhu et al, 2015;Li et al, 2020), groundwater (Edokpayi et al, 2018;, and polluted water by a large number of researchers. Zhao et al (2020) found that the human health risk through drinking water is two to three orders of magnitude greater than that of skin contact after the risk analysis of heavy metal pollution in the surface water of the Three Gorge Reservoir.…”