Contamination of PTEs in Sediment and Research

Abstract:

The concern of potential toxic elements (PTEs) contamination in the river ecosystem is growing due to anthropological activity. The contents of seven PTEs in sediments from the Balu River channel were analyzed using atomic absorption spectroscopy (AAS) and an environmental risk model. Several PTEs were found in the sediment at high levels, including zinc (Zn), copper (Cu), arsenic (As), lead (Pb), cadmium (Cd), nickel (Ni), and mercury (Hg), that might pose a risk to human and ecological health. The highest mean concentration of PTEs in sediment followed in decreasing order Zn (1365.21 mg/kg) > Cu (149.34 mg/kg) > Pb (46.34 mg/kg) > Ni (34.78 mg/kg) > As (6.31 mg/kg) > Cd (2.34 mg/kg) > Hg (1.03 mg/kg). In addition, most of these PTEs were significantly correlated (p < 0.05) among the sites and exceeded the safety guideline value. The geoaccumulation index (Igeo), contamination factor (CF), and pollution load index (PLI) showed high levels of PTEs contamination and moderately polluted to highly polluted levels of these elements. At the BL3, BL4, and BL6 sites within the study site, the ecological risk (PERI) score was extremely high, and the PERI values range found was from 75.39 to 355.72. Every PTE had a slightly greater concentration during the dry season than the wet season. Interestingly, PTE accumulation from sediment indicated non-carcinogenic risk (HQdermal) in human health, whereas most of the sites showed carcinogenic risk (CRdermal) to human health (adult and child) due to Cd and Ni accumulation. Multivariate statistical analysis (MVSA) indicated the most likely anthropological sources were the untreated wastes discharged in the river sampling area. People who come into contact with polluted sediments are constantly exposed to Ni and Cd pollution, which increases the risk of cancer and non-cancerous diseases. So, continuous PTE monitoring is advised by this study to assess ecological and human health risks.

Sources: Journal of Contaminant Hydrology 

https://doi.org/10.1016/j.jconhyd.2024.104492 

Potentially Toxic Elements Research

Abstract: There is concern over potential toxic elements (PTEs) impacting river ecosystems due to human and industrial activities. The river’s water, sediment, and aquatic life are all severely affected by the release of chemical and urban waste. PTE concentrations in sediment, water, and aquatic species from river ecosystems are reported in this review. Among the PTEs, chromium (Cr), cadmium (Cd), lead (Pb), and nickel (Ni) revealed high pollution levels in water and aquatic species (fish and shellfish) at many rivers. The Karnaphuli, Ganga, and Lee rivers have high levels of Pb and Cd contamination, while the Buriganga and Korotoa rivers’ water had notable Ni contamination. A number of rivers with PTEs showed ecological risk as a consequence of the sediment’s potential ecological risk (PER), the pollutant load index (PLI), and the geoaccumulation index (Igeo). A comprehensive study suggests elevated PLI values in river sediments, indicating significant pollution levels, particularly in the Buriganga River sediment, marked by high Igeo values. The PER of the Shitalakshya and Buriganga rivers was marked as very high risk, with an E i r > 320, while the Dhaleshwari and Khiru rivers showed ‘high risk’, with 160 = Ei r < 320. It was found that fish and shellfish from the Buriganga, Turag, and Swat rivers have a high concentration of Cr. PTE pollution across several river sites could pose health toxicity risks to humans through the consumption of aquatic species. The CR value shows the carcinogenic risk to human health from eating fish and shellfish, whereas an HI value > 1 suggests no carcinogenic risk. The occurrence of other PTEs, including manganese (Mn), arsenic (As), and nickel (Ni), significantly increases the ecological risk and concerns to aquatic life and human health. This study emphasises the importance of PTE toxicity risk and continuous monitoring for the sustainability of river ecosystems.

Source: Toxics 2025, 13(1), 26; https://doi.org/10.3390/toxics13010026 

Research on Invasive Asian Clam Species

Journal : Environmental Monitoring and Assessment

https://link.springer.com/article/10.1007/s10661-024-13322-6 

Abstract

The invasive Asian clam species, Corbicula fluminea, has significant ecological and societal implications at both local and international levels due to its nutritional aspects. C. fluminea from four urban rivers in Bangladesh exhibited negative allometric growth and degree of contamination with potentially toxic elements (PTEs), which posed a concern to human health based on the AAS and USEPA risk models. The highest mean concentration of PTEs followed a decreasing order: Zn (155.08 ± 4.98 mg/kg) > Cu (53.96 ± 7.61 mg/kg) > Mn (14.29 ± 3.25 mg/kg) > Cd (2.23 ± 0.10 mg/kg) > Pb (1.64 ± 0.14 mg/kg) > As (1.51 ± 0.45 mg/kg) > Ni (1.25 ± 0.27 mg/kg) > Cr (0.65 ± 0.02 mg/kg) in C. fluminea and raising safety concerns. With the exception of Cr and Mn, all element levels were exceeded safety guideline value (SGV) (mg/kg. ww) and exhibited a strong positive correlation (p < 0.05) among the sites. The target hazard quotient of Mn is THQ > 1, and As showed a non-carcinogenic risk in children at OBR, BR, and MR site. The hazard index (HI > 1) value at the BR and MR sites indicated a public health risk associated with the clam. The target cancer risk (TCR) values for As, Cd, and Ni showed that consuming clams posed a carcinogenic risk to human health. These findings suggest that eating these clams may put consumers at significant risk for health issues related to As, Cd, Ni, and Mn exposure. The study emphasizes the need for strict monitoring and preventative measures to reduce the health risks posed by PTEs contamination in clams.

Research Article

 

Source: Journal of Food Composition and Analysis.

https://doi.org/10.1016/j.jfca.2024.106540

 Abstract

The content of heavy metals in the food chain has grown due to human activities and rapid industrial growth. The accumulation of heavy metals in P. betel leaves and the related threat to human health were analyzed by using the AAS that was collected from eleven locations inside the city of Dhaka. High MDA contents indicated contamination in P. betel samples and can regulate biochemical activity by different potential toxic elements (PTEs). The P. betel samples revealed the highest mean concentrations of As (2.09 mg/kg), Pb (0.06 mg/kg), Mn (218 mg/kg), Ni (1.55 mg/kg), Cu (10 mg/kg), Zn (2.6 mg/kg), Cr (5.1 mg/kg), and Cd (0.003 mg/kg) and certain metal exceed the guideline value. Mn, Cr, and As mean values at the research sites are higher than the permitted concentration range. Among all metals, Mn was the most accumulated metal in leaves and enhanced hazard index (HI) and non-carcinogenic risk for children. Individual metal THQ values were all less than 1 (except Mn), indicating that consuming only one metal from betel samples would not pose a serious risk to one's health. However, HI value (> 1) indicates a possible non-carcinogenic health risk to urban city people, especially in children. The assessment revealed that the allowable range of Cr and As content in betel leaves may enhance the carcinogenic risk (CR). Among heavy metals, the CR value of Cr indicated an enhanced cancer risk in children at L3, L5, L6, L7, L8, L9, L10, and L11 sites. This study shows from a health perspective that people who eat contaminated betel leaves are continuously exposed to metal pollution, which can have both carcinogenic and noncarcinogenic effects.