Pollution status, health risk assessment of potentially toxic elements in soil and their uptake by gongronema latifolium in peri-urban of Ora-Eri, south-eastern Nigeria

Systematic assessment of source identification and ecological and probabilistic health risks of potentially toxic elements (PTEs) in soils of a typical coal mining area in Guanzhong region

Mining activities may cause the accumulation of potentially toxic elements (PTEs) in surrounding soils, posing ecological threats and health dangers to the local population. Therefore, a comprehensive assessment using multiple indicators was used to quantify the level of risk in the region. The results showed that the mean values of the nine potentially toxic elements in the study area were lower than the background values only for Cr, and the lowest coefficient of variation was 17.1 % for As, and the spatial distribution characteristics of the elements indicate that they are enriched by different factors. The elements Hg and Cd, which have substantial cumulative features, are the key contributors to ecological risk in the study region, which is overall at moderate risk. APCS-MLR model parses out 4 possible sources: mixed industrial, mining and transportation sources (53.98 %), natural sources (24.56 %), atmospheric deposition sources (12.60 %), and agricultural production sources (8.76 %). The probabilistic health risks show that children are more susceptible to health risks than adults; among children, the safety criteria (HI < 1 and CR < 10-4) were surpassed by 29.29 % of THI and 8.58 % of TCR. According to source-orientated health hazards, the element Ni significantly increases the risk of cancer. Mixed sources from industry, mining, and transportation are important sources of health risks. The results of this research provide some scientific references for the management and decrease of regional ecological and health risks.

Ecological pollution features and health risk exposure to heavy metals via street dust and topsoil from Nkpor and Onitsha in Anambra, Nigeria

The manuscript presents the investigation results on the pollution and risk of metal mines, and it is considered an important report on environmental pollution near mines in Nigeria, with archival value. The research involved soil sampling and heavy metal analysis for about 12 months in three metal mines. Based on these results, the paper provides information on pollution levels and hazards using well-known methods like pollution and ecological risk indexes. The increasing population in urban communities attracted by various industrial, economic and social activities causes contamination of atmospheric environment that can affect human health. We investigated heavy metal distributions, correlation coefficient among elements, ecological indices and probable health risk assessment in street dust and topsoil from Nkpor and Onitsha urban suburb, Nigeria. The mean concentration of heavy metals in car dust from Onitsha and Nkpor suburb follows thus: Fe > Mn > Cu > As > Pb > Ni > Cr. The decreasing trend of heavy metal in rooftop dust from both area: Fe > Mn > Cu > Pb > As > Ni > Cr whereas metal contents in topsoil were: Fe > Mn > Cu > Pb > Ni > Cr > As for both areas. The degree of pollution indices was characterized by contamination factor (CF), geo-accumulation factor (I-geo), pollution load index (PLI), Nemerow (PN), ecological and potential ecological risk index (ER and PERI) which indicated low pollution in the urban street environment. The results of Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that the estimated heavy metals displayed sources from atmospheric deposition, natural origin and anthropogenic sources. Risk assessment revealed that ingestion of dust and soil was the significant route for heavy metals exposure to the populace followed by inhalation, then dermal contact. Considering all factors, non-cancer risk was more prominent in children than adults and no significant health hazard could be attributed to both aged groups as of the period of study except for As and Ni that needs constant monitoring to avoid exceeding organ damaging threshold limit of 1 × 10-4.

From ground to gut: Evaluating the human health risk of potentially toxic elements in soil, groundwater, and their uptake by Cocos nucifera in arsenic-contaminated environments

This study aimed to gauge the toxicity of potentially toxic elements (PTEs) in coconut crops cultivated in arsenic-contaminated areas while offering a global perspective encompassing more than 100 impacted countries. The current investigation provides crucial insights into the assessment of PTEs pollution using the Bioaccumulation factor, Geo-accumulation index, Potential ecological risk index, Hazardous index, and Lifetime cancer risk (LCR) and highlights the potential human health risks posed by contaminated food, water, and soil. From 22 severely polluted sites in West Bengal, India, soil, groundwater (GW), and coconut water (CW) samples were collected, acidified, and digested using microwave digestion, for PTEs quantification using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results revealed that despite high concentrations of arsenic in soils (4.6 ± 3.4 mg kg-1), and GW (22.2 ± 150.9 μg L-1), CW (0.7 ± 3.1 μg L-1) levels were within permissible limits. Groups of PTEs with comparable sources and distributions were discovered through Principal Component Analysis (PCA). A speciation diagram was used to predict the prevalence of arsenic species in all three matrices. The Hazardous Index (HI < 1) indicated no probability of non-carcinogenic diseases for children and adults in all the compartments. However, exposure to GW and soil contaminated with Cr, As, and Cd by children (9.02 × 10-13 to 2.77 × 10-4) and adults (6.51 × 10-14 to 1.18 × 10-4) would increase their susceptibility to cancer (LCR >10-6). The study concluded that moderate lifetime consumption of CW is safe and has no significant impact on healthy individuals. Additionally, CW is a rich source of essential micronutrients such as Zn, Fe, Mn, and B. Overall, the findings of this study could help in developing appropriate strategies for reducing PTEs contamination and protecting human health.

Ecological pollution and health risk monitoring assessment of polycyclic aromatic hydrocarbons and heavy metals in surface water, southeastern Nigeria

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are predominant pollutants linked with anthropogenic activities across a host of environmental mediums. The level of pollution, ecological and health risk were assessed in surface water from Ekulu in Enugu metropolis, Nigeria for 17 PAHs and selected HMs (As, Cd, Cr, Cu, Pb, Ni, Zn) components. PAHs and HMs were determined using a gas chromatography-flame ionization detector (GC-FID) and atomic adsorption spectrophotometer (AAS). The total PAHs in station A (3.17mg/l), B (1.51mg/l), and C (1.83mg/l) were due to high molecular weight (HMW) PAHs than low molecular weight (HMW) PAHs. HMs contents were within USEPA and WHO minimum contamination levels (MCL) except Cr and Pb. The molecular diagnostics of PAHs showed that incomplete combustion of carbonaceous compounds was dominant, while petrogenic was insignificant across all samples. The ecological indices of PAHs and HMs varied from medium to high pollution due to anthropogenic activities that pose a threat to the ecosystem. The non-carcinogenic models showed that hazard index (HI) ranged from PAHs (0.027 - 0.083) and HMs (0.0067 - 0.087) which is less than unity implying no adverse health issues. The lifetime cancer risk (LCR) for PAHs (4.21×10-4 - 9.61×10-4) and HMs (1.72×10-5 - 3.98×10-5) suggested significant cancer risk is possible over some time for a population of 1 in 10,000 and 100,000 for both PAHs and HMs exposure for 70 years. Therefore, there is an urgent need for proper pollution control and mitigation plan to preserve both age groups from being continuously exposed to anthropogenic activities in the Ekulu River and further study should be carried out to monitor the available toxicants.

High-resolution risk mapping of heavy metals in soil with an integrated static-dynamic interaction model: A case study in an industrial agglomeration area in China

Heavy metal pollution of soils in industrial agglomeration areas is an increasing concern worldwide. In this study, we traced the sources of heavy metal emissions using a positive matrix factorization (PMF) model. Accordingly, we proposed a novel static-dynamic risk interaction model incorporating multiple risk-related factors to quantify the spatial interaction of emission sources and the probability of accumulation of heavy metals on a large scale. This model was further classified using the Jenks optimization technique to predict the spatial distribution of high-risk hotspots. Our results determined four primary emission sources of heavy metals: industrial (35.01 %), natural (28.61 %), agricultural (26.07 %), and traffic (10.31 %) sources. Five levels were classified by the integrated risk coefficient (IRC), namely, from extremely high to extremely low risk. The extremely high- and high-risk hotspots constituting 41.52 % of the total area of the Zhenhai District, with IRC values ranging from 0.221 to 0.413, were mainly generated by multiple sources linked to PMF-based factors. This quantitative evaluation framework can generate a high-resolution spatially distributed pollution risk map at the grid scale (1 km), which can provide a relatively precise basis for policymaking for point-to-point soil pollution management.

Effect of storage on the levels of sodium benzoate in soft drinks sold in some Nigerian market with exposure and health risk assessment

Soft drinks consumption is still a controversial issue for public health and public policy, as the influence storage condition impacts taste, color and shelf life. In all, fifty (50) soft drinks samples, acquired from Enugu, Aba, Asaba, Onitsha and Owerri markets in Nigeria, were subjected to four different storage conditions namely: room temperature (RT), refrigerated (RF), 40 °C and 60 °C for 15 days after which they were analyzed for sodium benzoate concentration using HPLC - UV/Vis detector. The results showed on the average that at RT and RF, soft drinks from Aba had the highest concentration of sodium benzoate (98.7 mg/L and 112.9 mg/L) respectively while samples from Asaba had least concentration of 39.9 mg/L and 38.1 mg/L. At increased temperature of 40 °C, the concentration of sodium benzoate increased generally across the sample, while at 60 °C, the levels in all the samples analyzed were either reduced to less than 50% or below detection level, which suggest that degradation of sodium benzoate at this elevated temperature could result in benzene formation, which is a known carcinogen. Carcinogenic and non-carcinogenic risk assessment showed that children are at risk compared to adults due to higher sodium benzoate daily intake leading to high rate of hyperactivity in correlation to malaise.