Priority control factors for heavy metal groundwater contamination in peninsula regions based on source-oriented health risk assessment.

Peninsula regions in China face serious environmental issues, such as heavy metal (HM) groundwater contamination. However, attempts to investigate the pollution sources and health risks of HM contamination in such regions require considerable resources and costs. Moreover, the priority control factors for groundwater HMs remain unclear. In this study, absolute principal component score/multiple linear regression (APCS/MLR) was used to quantify the groundwater pollution sources of typical peninsular areas in China, and a health risk assessment (HRA) was performed to assess the health risks caused by different sources. The results showed that the concentrations of Mn and Fe were higher than those of other HMs, and HM pollution was high in shallow groundwater. The dominant source of HMs in groundwater was agricultural activities (31.12 %), followed by natural sources (26.33 %), industrial activities (22.47 %), and atmospheric deposition (20.09 %). The non-carcinogenic risks to residents were acceptable, whereas the carcinogenic risks were high. Agricultural sources, atmospheric deposition sources, and Cr and As were identified as the priority control factors for HM groundwater contamination. This study has implications for improving the control of groundwater HM contamination in peninsula regions and ensuring sustainable groundwater development.

Health Risk Assessment of Heavy Metals in Groundwater of Hainan Island Using the Monte Carlo Simulation Coupled with the APCS/MLR Model.

Groundwater is a significant component of water resources, but drinking groundwater with excessive heavy metals (HMs) is harmful to human health. Currently, quantitative source apportionment and probabilistic health risk assessment of HMs in groundwater are relatively limited. In this study, 60 groundwater samples containing seven HMs were collected from Hainan Island and analyzed by the coupled absolute principal component scores/multiple linear regression (APCS/MLR), the health risk assessment (HRA) and the Monte Carlo simulation (MCS) to quantify the pollution sources of HMs and the health risks. The results show that the high-pollution-value areas of HMs are mainly located in the industry-oriented western region, but the pollution level by HMs in the groundwater in the study area is generally low. The main sources of HMs in the groundwater are found to be the mixed sources of agricultural activities and traffic emissions (39.16%), industrial activities (25.57%) and natural sources (35.27%). Although the non-carcinogenic risks for adults and children are negligible, the carcinogenic risks are at a high level. Through analyzing the relationship between HMs, pollution sources, and health risks, natural sources contribute the most to the health risks, and Cr is determined as the priority control HM. This study emphasizes the importance of quantitative evaluation of the HM pollution sources and probabilistic health risk assessment, which provides an essential basis for water pollution prevention and control in Hainan Island.

[Hydrochemical Characteristics and Controlling Factors of Groundwater in the Leizhou Peninsula].

Groundwater resources in the Leizhou Peninsula provide a strong support for the economic and social development. Therefore, understanding the chemical characteristics and formation mechanism of groundwater in this area is necessary for the rational exploitation and sustainable utilization of water resources. In this study, 43 groundwater samples were collected, and the hydrochemical characteristics and controlling factors were analyzed by descriptive statistical analysis, Piper triangular diagrams, ArcGIS spatial interpolation, Gibbs diagram, and ion ratios. The results showed that:① The anions and cations of the groundwater in the study area were mainly HCO3-, Ca2+, and Na+, and the hydrochemical types were mainly HCO3-Cl-Na-Ca, HCO3-Cl-Na-Ca-Mg, HCO3-Cl-Na-Mg, and HCO3-Na. The contents of Cl-, SO42-, and Na+were higher in the west of Leizhou City compared to other areas. The sites with higher contents of HCO3-, NO3-, Ca2+, Mg2+, and K+ were mainly concentrated in the southwest and eastern coastal areas. ② The chemical evolution of groundwater was mainly affected by water-rock interaction, cation alternating adsorption, and anthropogenic activities. The sources of Na+ and K+ were mainly from evaporative and silicate rocks, Ca2+ and Mg2+ were mainly from carbonate karstification, while NO3- originated from anthropogenic activities.

[Source Analysis and Health Risk Assessment of Heavy Metals in Groundwater of Leizhou Peninsula].

Source identification and health risk assessment of heavy metals in groundwater is one of the key issues in China's new era of environmental management. In order to reveal the status, sources, and health risk of pollutants in groundwater of the Leizhou Peninsula, 44 groundwater samples were collected, and the concentrations and spatial distribution of Cr, Mn, Cu, Zn, As, Cd, Hg, and Pb were measured and analyzed. The sources of heavy metals in groundwater were then determined through correlation coefficient and principal component analysis. Finally, the health risk model was used to evaluate the different health risks associated with these heavy metals. The results showed that the average value of heavy metal elements in groundwater of the Leizhou Peninsula does not inferior to the class Ⅱ water quality standard(GB/T 14848-2017). However, As, Mn, and Cd do not meet the standard. The overall spatial distribution indicated obvious spatial differences, with higher values in the south than in the north. Heavy metal sources can be identified as three principal components (PCs). PC1 (Cu, Zn, Cd, and Pb) metals mainly originate from industrial, agricultural, and traffic sources. PC2 (Cr, Mn, and As) sources can be both natural and man-made, and PC3 (Hg) sources are primarily man-made. For the groundwater of the Leizhou Peninsula, the health risks of 8 metals are with the acceptable range, the carcinogenic risk of adults is higher than that of children, and the risk of drinking exposure is higher than that of skin exposure. The study shows that the environmental protection department should encourage the rational exploitation of groundwater resources and control the sources of pollution to reduce health risks.