In recent decades, the ecological environment of some coastal areas in China has been seriously affected by terrestrial pollutants, and there is an urgent need for ecological risk assessment of China’s coastal environment. The assessment of heavy metal pollution in Hong Kong waters was carried out using different environmental and ecological indicators. The heavy metal contents (Cu, Pb, Zn, Cd, As, Cr, and Hg) in the near coast of Hong Kong were analyzed for two different seasons of the year 2018 (April—spring and September—autumn). We assessed the distribution and enrichment of heavy metals in the near coast of Hong Kong, and the potential biohazardous effects were assessed using the species sensitivity distribution method. The results showed that only Pb, Zn, and Hg in seawater exceeded the Class I standard. Pb, Zn, Cd, and As in organisms exceeded the standard, and no heavy metals exceeded the standard in sediments. The species sensitivity distribution method indicated that the biohazardous factor of heavy metals of the Hong Kong coast is higher in spring than in autumn, and the potential hazard ratio has the characteristics of high northwest and low southeast, which leads to its msPAF also having these characteristics. From the correlational analyses among heavy metals, we found that the pH change in seawater was related to the concentration of heavy metals, the concentration of heavy metals in seawater was proportional to the salinity of seawater, Pb and Cu were likely to have the same source, and Zn and Cd may not have the same emission sources as the other heavy metals. Overall, heavy metal contamination of seawater, sediments, and organisms near the Hong Kong coast was within acceptable limits, but the problem of heavy metal dispersion should be prevented.

Environmental magnetism parameters have become a useful tool in addressing environmental issues. Due to the rapid, sensitive, economical and non-destructive characteristics of environmental magnetism, the present contribution focuses on magnetism parameters as proxy for heavy metal pollution, especially from their relationship with contents of heavy metal. We evaluated heavy metals pollution and examined environmental magnetism in the Dexing section of the Le’an River. The pollution load index (PLI) of Cr, Pb, As, Cu and Zn, as well as the concentration of other heavy metals, were analyzed, and the magnetic indexes of various sediments were analyzed. The results showed that the concentrations of all heavy metals far exceeded the local background values, and that the average contamination factor of Cu was as high as 22.88, making it the element of most serious contamination. The problem of heavy metal pollution near the mine is very serious. The content of magnetic minerals in sediments of Le’an River is relatively high and the composition of magnetic minerals is relatively stable. The stable-single domin (SSD) content is high at S1 and S10, indicating that ferromagnetic mineral content is relatively rich here, which dominates the magnetic characteristics of the sample. In general, it was found that environmental magnetism indicators did not exist in the Dexing section of the Le’an River that could clearly indicate the concentration of heavy metal pollution. Only a few heavy metals can be effectively indicated by magnetic parameters. IRM_-20mT and S_-ratio can be used as indicators of Cr, Pb, As, Cu and Zn, but they are not accurate. The correlation between Sr and magnetic indexes IRM_200mT, IRM_300mT, SIRM, IRM_-300mT and HIRM is significant, which can be used as an indicator of Sr concentration. IRM_20mT can also be used as an indicator of Hg concentration.

The problems of water shortages and groundwater overexploitation are serious in Beijing. Resources are over-exploited to meet the industrial needs of various sectors, and the capacity of groundwater resources to support economic development is also reduced. Therefore, it is of great significance to study the evaluation of regional groundwater resources carrying capacity from the perspective of time and space. This study evaluates the groundwater resource carrying capacity of Beijing from time and space by using the function between water use efficiency and groundwater availability constructed by regional water supply, consumption data and GDP data. The results show that: The proportion of groundwater in water supply in Beijing has decreased and it was still one of the main sources of water supply from 2010 to 2020. From the perspective of time, when the degree of groundwater exploitation (De) was greater than 1, the contribution rate of exploitation degree of economic development (Dg) reached 60% from 2010 to 2015, indicating that the economic development of Beijing is highly dependent on groundwater resources. From 2015 to 2020, the De was less than 1, but the Dg value kept increasing and approaching 90% and the total overload rate was 81.8%. The supporting capacity of groundwater resources will become more fragile. At the spatial scale, only the Dongcheng and the Xicheng regions were overloaded whose rates were 58.48% and 69.92%. The research shows that the degree of groundwater exploitation has approached the saturation state, the economic development is highly dependent on groundwater resources and there is a large space for water saving. Improving the utilization efficiency of water resources cannot improve the carrying capacity of groundwater resources, so it is still necessary to increase the amount of groundwater resources by recharging the groundwater through a series of comprehensive over-exploitation control measures, which is of great significance to the management and sustainable development of regional groundwater.