Tracing sources and ecological risks: seasonal-spatial variations of potentially toxic element (PTE) pollution in marine sediments of Beibu Gulf.

Source-specific ecological and health risks of potentially toxic elements in agricultural soils in Southern Yunnan Province and associated uncertainty analysis

This study investigated the accumulation levels, ecological and health risks, and the impact of socio-economic development on potentially toxic elements (PTEs) present in road dust collected from the major roads of low latitude industrialized City, Dongguan, China. The concentrations of PTEs decreased in the order of zinc (Zn) > lead (Pb) > chromium (Cr) > arsenic (As) > cadmium (Cd) > mercury (Hg). Similarly high levels of Cd and Zn accumulation were observed, and other PTEs were generally moderately accumulated or enriched. The ecological risk was relatively high for Cd and Hg and low for other PTEs. Most of sampling sites were moderately to heavily polluted, and the ecological risk was generally moderate to very high. The non-carcinogenic risks to both adults and children were safe at internationally accepted levels. However, higher levels of carcinogenic risk were observed in males and females, mainly due to the contribution of Cr and As. Spatial distribution patterns revealed higher accumulation level, ecological and health risks in districts of Binhai, Central City with higher GDP. In the present study, a positive relationship was observed between PTEs concentrations and GDP of Dongguan's six districts (R = 0.66, p = 0.15) and a similar significant pattern was revealed for the first time at the global level (R = 0.66, p = 0.0021). It is evident that socio-economic development had a significant impact on PTEs contamination and the resulting ecological and health risks. Therefore, industrial cities such as Dongguan need to adopt broader strategies that decouple the relationship between socio-economic development and the emission of PTEs concentration (e.g. Cd, Cr and As), to mitigate this emission during economic growth and transition towards a more sustainable development model.

Ecological risk assessment and sources identification of potentially toxic elements in the surface sediments of Qinghai Lake

Concentrations, spatial distribution, sources and environmental health risks of potentially toxic elements in urban road dust across China

The primary goals of this study were to reveal the environmental status of potentially toxic elements (PTEs) and their ecological risks, as well as their associated health risks in the Baoshan area, southwest China, which has been surveyed with the scale of 1:250,000 geochemical mapping. Based on a comparison of the PTE concentrations with the soil environmental quality of China and the enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (Cf), and potential ecological risk indexes (Eri and PERI), as well as the potential non-carcinogenic hazard indices (HI and CHI) and carcinogenic risks indices (TCR and CTCR), the following conclusions were drawn: The PTE concentrations in the surface soil samples that were collected from the investigated area (1.65% sites) exceeded the risk intervention values (RIV) for soil contamination of agricultural land of China. Cadmium (Cd) and mercury (Hg) posed higher ecological risks than other PTEs (arsenic (As), chromium (Cr), lead (Pb), copper (Cu), nickel (Ni), and zinc (Zn)), which was highlighted by their toxic response factor. Arsenic was the main PTE with a non-carcinogenic risk (19.57% sites for children and 0.25% sites for adults) and the only PTE that carries a carcinogenic risk (2.67% sites for Children and 0.76% sites for adults) to humans in the research area. Children are more vulnerable to health risks when compared to adults because of their behavioral and physiological traits. Geological genesis was responsible for the high concentrations, ecological risk, and health risk distribution patterns of the examined PTEs. Even though the present research highlights several important aspects related to PTE pollution in the research area, further investigations are needed, especially in mining areas.

Rapid developments in industrialisation and urbanisation have resulted in serious environmental pollution. It is therefore imperative to evaluate contamination levels, sources, and ecological and human health risks of potentially toxic elements (PTEs) in soils. This work examined the degree of PTE pollution in soils collected from Ikorodu Industrial Layout in Lagos, Nigeria. Concentrations of PTEs were determined by digesting the soil samples with aqua regia and analysing them using an atomic absorption spectrophotometer (ICE 3000 series). The results showed that the majority of the PTEs analysed did not exceed the guideline values, but Zn was enriched at about 27% of the sampling locations. The enrichment and contamination factor computations revealed Zn and Ni as the highest and lowest contaminants, respectively. Pollution assessment tools employed Enrichment factor and Contamination factor (EF and CF) showed a similar PTE pattern (in descending order): Zn > Pb > Cd > Cu > Fe > Mn > Ni. Ecological risk assessment revealed that about 70% of sampling locations had significant potential ecological risks. Correlation and hierarchical clustering identified geogenic, anthropogenic and mixed contributions to soil PTE load. Hazard index indicators for children and adults wer less than 1, which suggests there was no potential for significant toxicity risks. Carcinogenic risks were estimated for Cd, Ni and Pb and results were within acceptable risk levels, but children are more vulnerable to cancer and non-cancer risks than adults.

Deciphering multi-media occurrence and anthropogenic drivers of potentially toxic elements in a rapidly urbanized estuary: A neural network-enhanced source apportionment.

Changes in ecological and health risk assessment indices of potentially toxic elements associated with ambient air particulate matters (PM2.5) in response to source, land use and temporal variation in Isfahan city, Iran

In this study, the contamination, ecological and human health risks as well as source apportionment of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and V in street dusts of different land-uses in Kermanshah, Iran were investigated. A total of 192 dust samples were taken from 16 sites and were analyzed for their elemental contents using ICP-OES. The computed mean values for the geo-accumulation index (I-geo) and the pollution index (PI) ranged from − 6.07 to 2.67 and from 0.023 to 9.58, respectively, indicating ‘unpolluted’ to ‘moderately to heavily polluted’, and ‘slight to very high polluted’ pollution levels, respectively. The pollution load index (PLI) with a cumulative mean value of 1.03 reflected moderate pollution levels across the entire study area. Moreover, the ecological risk (RI) of 135 indicated moderate ecological risks throughout the study region. The mean hazard index (HI) values for the analyzed potentially toxic elements (PTEs) for both adults and children were all within the safe limit (< 1). Furthermore, the total carcinogenic risk (TCR) values showed that the carcinogenic risks associated with As, Cd, Cr, and Ni for both target populations were at tolerable to unacceptable levels. The positive matrix factorization (PMF) model identified traffic emissions and sources, fossil fuel combustion and natural sources, and industrial emissions as the major sources of tested elements. Hence, a thorough investigation into the sources of ecological health risks associated with dust contamination from potentially toxic elements (PTEs) is recommended for future studies.

In this study, a total of 180 Pinus eldarica bark samples were collected from different regions of Hamedan megacity, Iran, in 2023, and contents of Cd, Cr, Cu, Mn, Ni, Pb, and Zn in the samples were determined using ICP-OES. The results illustrated that the average contents of all the analyzed elements were greater than those in the background contents, which presumably demonstrated anthropogenic sources of these potentially toxic elements (PTEs). The greatest concentrations of the analyzed PTEs for different functional areas were observed in specimens collected from commercial or industrial areas, indicating the impact of human entries. The I-geo values were in the range of "unpolluted to moderately polluted" to "moderately to heavily polluted", PI showed "moderate to very high pollution", and PLI reflected high to very high pollution levels for the whole study area. Additionally, the cumulative mean value of ecological risk (RI) was found to be 152, demonstrating moderate ecological risk across the study area. The results of positive matrix factorization (PMF) showed that the PTE contamination in the air of Hamedan could mainly have an anthropogenic origin (82.7%) and that the traffic emissions as the primary pollution source (33.6%) make the highest contribution to the PTE pollution and ecological risks in the study area. In residential areas, demolition and construction activities could be considered the main sources of PTEs, while in commercial and industrial areas traffic emissions and industrial emissions, could be regarded as the main sources of such pollution, respectively. In conclusion, this study provides a useful approach to identifying the sources and contributions of the toxic elements in different functional areas and can inform future endeavors that aim at managing and controlling metal element pollution.

Characterization, source identification, risk assessment of potentially toxic elements (PTEs) in the surface water and sediment of the Beibu Gulf, China

It is crucial for effectively controlling potentially toxic element (PTE) pollution to understand the pollution situation, ecological risks, health risks, and migration patterns of PTEs. However, currently, no research has been conducted on the migration patterns of soil PTEs from coal mining subsidence areas to waterlogged areas under different restoration modes. In this study, a total of 15 sediment samples and 60 soil samples were collected from landscaped wetlands, aquaculture wetland, fish–photovoltaic complementary wetland, photovoltaic wetland, and waterlogged areas with untreated coal mining subsidence. The PTE pollution status, ecological risks, health risks, migration patterns, and the important factors influencing the migration were analyzed. The results indicated that the comprehensive pollution level of PTEs in waterlogged areas with coal mining subsidence can be reduced by developing them into landscaped wetlands, aquaculture wetlands, fish–photovoltaic complementary wetlands, and photovoltaic wetlands. Additionally, the closer to the waterlogged area, the higher the Cu content in the subsidence area soil is, reaching its peak in the waterlogged area. The Cd was influenced positively by SOC and pH. The research results were of great significance for formulating reclamation plans for waterlogged areas and controlling PTE pollution.

With rapid economic and industrial development, the potentially toxic element (PTE) pollution of farmlands in China has become increasingly serious. Based on the Hakanson potential ecological risk index (RI) and national food pollutant limit standards (GB 2762-2017), the effects of exogenous potentially toxic elements (PTEs), i.e., arsenic (As) and mercury (Hg), on rice growth were studied. Common varieties of hybrid (YY 538, CY 84) and conventional (XS 134, JH 218) rice were grown in pots having representative paddy soil from Zhejiang Province, China. The results showed that As and Hg in soil significantly inhibited growth; however, the plant height of hybrid rice was less affected. Further, there were significant correlations between concentrations of PTEs in soil and rice grains; however, hybrid rice had a stronger ability to absorb and accumulate PTEs. The comprehensive potential ecological RI of soil PTEs was 39.4–89.9, which is below the level of ‘minor ecological hazard’, and the contribution rate of Hg was 79.9%–84.2%; as such, Hg posed the greatest potential ecological risk in the study area. The ecological risk limits of As and Hg in the safe production of different rice varieties decreased in the order XS 134 &gt; JH 218 &gt; YY 538 &gt; CY 84. The ecological risk limits of As and Hg for conventional rice were higher, and the risk limits of As and Hg for hybrid rice were lower, than the limit of the soil environmental quality assessment index in the national “Soil quality control criteria for soil pollution in agricultural land (for trial implementation) (Trial)” (GB15618-2018). The health risk limit of soil As in the typical paddy soil of China decreased in the order XS 134 &gt; JH 218 &gt; CY 84 &gt; YY 538. The health risk limit of Hg decreased in the order XS 134 &gt; JH 218 &gt; YY 538 &gt; CY 84. The health risk limit of As was lower, whereas the risk limit of Hg was higher, than the limit of the soil environmental quality evaluation index in the national “Soil quality control criteria for soil pollution in agricultural land (for trial implementation) (Trial)”(GB15618-2018).

Potentially toxic elements in lake sediments in China: Spatial distribution, ecological risks, and influencing factors

Comprehensive assessment of exposure and environmental risk of potentially toxic elements in surface water and sediment across China: A synthesis study