Open Access

Article

Article ID: 2115

Bioaccumulation of metals and metalloids in soils and in the earthworm Hyperiodrilus africanus from uncontrolled landfills in Kinshasa, Democratic Republic of the Congo

by Marie-Madeleine O. Akonga, Honoré M. Mutwejile, René V. Gizanga, Jean S. Kayembe, Dieudonné E. Musibono, Fernando P. Carvalho, John Poté, Emmanuel K. Atibu

Journal of Toxicological Studies, Vol.3, No.1, 2025;

To better understand the ecological impact of pollutants from uncontrolled landfills and to assess the potential risks they pose to terrestrial ecosystems and public health, soil samples were collected from uncontrolled landfills in three municipalities of Kinshasa and analyzed for 17 metals and metalloids (including metals Fe, Zn, Mn, Cu, Pb, Cr, Co, Sn, Ni, Cd, Sc, Ag, Mo, and Hg, and metalloids Se, As, Sb) using ICP-MS and AAS. The following decreasing order of elemental concentrations was generally observed in soils: Fe > Zn > Mn > Cu > Pb > Cr > Co > Sn > Ni > Cd > Se > As > Sb > Sc > Ag > Mo > Hg. The Geoaccumulation Index (Igeo) and the Enrichment Factor (EF) indicated very severe to extremely severe soil contamination by metals, with high enhancement of Cu, Zn, As, Ag, Cd, Sb, Pb, and Hg concentrations. Furthermore, several ecotoxicological indices, such as the Potential Ecological Risk Index (RI), highlighted serious soil pollution, particularly in the samples from the landfill receiving industrial waste at Limete municipality. Therefore, the use of these soils from uncontrolled landfills for fertilization of agricultural fields, as farmers currently do, poses a serious risk to public health. Concentrations of metals and metalloids were determined also in the earthworm Hyperiodrilus africanus, collected in the same areas, and the earthworm bioaccumulation factor (on a dry weight basis) displayed values greater than one in most samples and up to 15.3. This bioaccumulation of metals and metalloids from the soil suggests that earthworms can be used as a bioremediation agent for contaminated soils. Based on the results from this research, several recommendations are made to improve the pollution control and to protect public health.

Open Access

Review

Article ID: 2772

Heavy metals in the environment: Detection techniques and toxicity

by Imene Hadj Henni

Journal of Toxicological Studies, Vol.3, No.1, 2025;

Heavy metals are characterized by their relevance, toxicity, and capacity to accumulate in the natural environment. Therefore, their emission into the air can cause long-term environmental hazards. In addition, they can be transported in the atmosphere over long distances and deposited in regions far from the emission location. Among the pollutants currently implicated by their toxicity in the environment, we can cite, in order of importance, mercury, cadmium and lead, which are currently a matter of concern. Mercury is transported over long distances in the atmosphere, and its biotransformation into toxic methylated compounds and bioaccumulation in the trophic chain have made it a major pollutant. Cadmium, which is relatively rare and is mainly found in ores, is considered one of the most toxic metals. Its accumulation in different types of sediment and its capacity for remobilization constitute particularly worrying risks. Finally, although Pb is less toxic than Hg and Cd, it is very abundant in its natural state and is used in large quantities in industry, which makes this ubiquitous toxin a permanent threat to the health of populations. This review provides an analysis of the occurrence of heavy metals in the environment, including Cu, Pb, Ni, Hg, Cr, Zn, Fe, and Cd, their toxicity potential, their impact on human health, and detection technologies using Field-Effect Transistor (FET) sensors.

Open Access

Article

Article ID: 2201

Protective role of exercise and curcumin on regional BMD and oxidative stress induced by lead

by Valiollah Dabidi Roshan, Sara Pouriamehr

Journal of Toxicological Studies, Vol.3, No.1, 2025;

The current study aimed to assess the impacts of 8-week non-pharmacological strategies on the regional bone mineral density (BMD) and the oxidative stress among rats regarding lead acetate (Pb) exposure. Randomly, we divided 40 rats into 5 groups: Pb, SHAM, curcumin+Pb, exercise+Pb, and curcumin+exercise+Pb. The rats received Pb (20 mg/kg), curcumin solution (30 mg/kg), and/or treadmill running 5 times/week during an eight-week research protocol. The femur and tibia regional BMD were measured by the DEXA system. Additionally, blood collections were performed to measure oxidative/antioxidant markers. It was demonstrated that BMD lessened significantly in the femur and tibia of rats exposed to Pb, particularly in their distal epiphysis. Whereas TBARS remarkably elevated, TAC dropped in the Pb group. On the other hand, the curcumin supplementation alone did not affect BMD, while performing the weight-bearing exercise resulted in a significant elevation of BMD in spongy tissue (i.e., the proximal and distal epiphysis of femur and tibia bones), specifically a combination of exercise and curcumin consumption protocols. Therefore, exercise training and consuming curcumin supplements may provide osteoprotective benefits against Pb-induced toxicity.

Open Access

Article

Article ID: 2187

Tracking heavy metal pollution and potential ecological threats in soils around Mfamosing cement plant, Nigeria

by Udiba U. Udiba, Blossom U. Ejah, Abo I. Nta, John Ama, Amah J. Etim, Ekom R. Akpan, Ekpo E. Antai

Journal of Toxicological Studies, Vol.3, No.1, 2025;

This study, conducted from June to December 2022 around the Mfamosing cement plant in Akamkpa, Nigeria, evaluated soil pollution status and potential ecological risks posed by heavy metals using an Atomic Absorption Spectrophotometer (Model AA-6800, Japan) after wet digestion. The ranges of lead, cadmium, mercury, arsenic and chromium concentrations (mg/kg) were: 9.11–84.73, 0.21–9.94, 0.64–0.78, 4.63–5.92, 8.25–37.23 respectively. The mean soil metals concentrations were below US-EPA maximum permissible limits and Dutch soil intervention values, cadmium being the only exception. The high spatial variations reflecting decreased metal levels with increasing distance from the cement plant suggest the cement plant may be responsible for the elevated soil metal concentrations. Metals contamination factors correspond to contamination status ranging from low contamination to very high contamination. Index of geo-accumulation (Igeo), revealed that Farms 1, 2, 3, and 4 ranged from unpolluted to strongly polluted. Ecological risk factor revealed that the metals pose a range of low to high potential ecological risk to other components of the environment. Given these findings, metal speciation analysis is strongly recommended to better understand the mobility, bioavailability, and toxicity of the contaminants. This would provide essential insights into potential uptake by crops, ecological transfer, and leaching risks, thereby guiding more targeted environmental management and remediation strategies.

Open Access

Article

Article ID: 1570

Prevalence and impact of dye adulteration in toffee consumption: A case study on mildly acute or acute toxicity affecting the population in misbranded toffee and candy consumption; an occupational health study report and branding strategies in marketing new products

by Saurabh Dilip Bhandare

Journal of Toxicological Studies, Vol.3, No.1, 2025;

Advancements in toxicological research have led to the development of several innovative methods for assessing the safety and potential risks of chemicals and toxic substances. This study investigates the prevalence and health implications of dye adulterants in toffees in excess amount from various brands distributed during a corporate year-end evaluation in Navi Mumbai, New Bombay 2015. The research employs random and stratified sampling methodologies to ensure a comprehensive analysis of the market. Laboratory tests reveals that dye X is present in 100% of samples from each brand, contradicting the natural flavour labels. Descriptive statistics indicate variations in dye concentration among brands, and ANOVA results demonstrate statistically significant differences in mean dye concentrations. Despite the presence of dye X across all brands, the chi-square test does not show a significant association between dye presence and brand at a 0.05 significance level. Employees reported adverse health effects, including dysuria, fatigue, and cardiovascular disturbances, after consuming the toffees, and tea. These findings highlight the need for stringent regulatory measures and consumer awareness to ensure food safety and mitigate health risks associated with food dye adulteration. The primary focus of this research study was to advance new methodologies for health monitoring and toxicology analysis that minimise large-scale disruptions. It aimed to foster innovation in medical science and establish new, documented methods for healthcare practitioners and professionals. These methods are designed to comprehensively analyse and document toxic events and systematically record data, enhancing the ability to manage and understand toxicological risks in a more controlled and efficient manner.

Open Access

Article

Article ID: 2216

Assessment of heavy metal contaminations in irrigation water, soils, and onions in the Isser and Zemmouri Regions, Algeria

by Younes Mohamed Aksouh, Amal Rabahi, Nadjib Benosmane

Journal of Toxicological Studies, Vol.3, No.1, 2025;

This study investigates heavy metal contamination in irrigation water, soil, and onion (Allium cepa L.) samples from the Isser and Zemmouri regions of Boumerdes, Algeria, to assess potential health risks from consuming these vegetables. The analysis focused on both essential and toxic heavy metals, including iron (Fe), copper (Cu), zinc (Zn), cadmium (Cd), chromium (Cr), lead (Pb), and nickel (Ni). Atomic Absorption Spectroscopy (AAS) was employed for accurate quantification, and results were compared with FAO/WHO 2001 standards. Elevated copper (0.72 mg/L) and zinc (0.19 mg/L) levels were detected in Isser’s irrigation water, while Zemmouri’s water contained near-threshold concentrations of nickel (0.18 mg/L), chromium (0.09 mg/L), and copper (0.14 mg/L). Soil contamination was observed at both sites, with Isser showing high Cu (68.41 mg/kg), Zn (62.12 mg/kg), and Pb (71.63 mg/kg) levels, while Zemmouri exceeded limits for Pb (64.32 mg/kg) and Ni (11.21 mg/kg). In onion bulbs, Isser showed elevated chromium (3.1 mg/kg) and lead (0.31 mg/kg), while Zemmouri exhibited high zinc (11.34 mg/kg) and iron (43.76 mg/kg) levels in leaves. These findings indicate significant health risks associated with onion consumption from these regions, highlighting the need for improved monitoring and management of water quality and agricultural practices.