Sources evaluation, ecological and health risk assessment of potential toxic metals (PTMs) in surface soils of an industrial area, India

Concentration of heavy metals in soil and leaves of Conocarpus Erectus Tree: A Biomonitoring Study, Ahvaz, Iran

Heavy metals biomonitoring was performed using the Conocarpus erectus tree in Ahvaz city. Composite leaf and soil samples were collected from 23 selected stations. The concentrations of heavy metals (Pb, Zn, Cd, Cu, Fe and Mn) in leaf and soil samples, and bioavailability of metals in soil samples were determined. Examination of soil physicochemical parameters proved neutral to slightly alkaline nature, and low organic matter content in the soil samples. The mean concentration of heavy metals in soil was: Fe > Mn > Zn > Pb > Cu. Ecological risk assessment of heavy metals was in the range of safe to low risk (RI < 150). Although the concentration of metals in the more polluted areas was higher in both leaf and soil samples, there was no significant relationship between the concentrations of metals in the leaf and soil samples. This relationship is even lower between the bioavailable component of metals in the soil and the concentration of metals in the leaves. Transfer factor values based on total contents of metals in soil samples indicated that Conocarpus erectus is mostly contaminated with Zn and Cu. The results of Accumulation factor of plant revealed that Pb, Zn, and Fe were mostly enriched in the plant by anthropogenic activities. MAI values in heavy and light traffic, and industrial areas were 11.88, 8.01 and 8.15, respectively. In general, it is evident that the Conocarpus erectus leaves accumulate heavy metals in polluted areas, so it can be used as a bioindicator of air pollution with heavy metals in regions with similar conditions.

Risk assessment and strontium isotopic tracing of potentially toxic metals in creek sediments around a uranium mine, China

The contamination of creek sediments near industrially nuclear dominated site presents significant environmental challenges, particularly in identifying and quantifying potentially toxic metal (loid)s (PTMs). This study aims to measure the extent of contamination and apportion related sources for nine PTMs in alpine creek sediments near a typical uranium tailing dam from China, including strontium (Sr), rubidium (Rb), manganese (Mn), lithium (Li), nickel (Ni), copper (Cu), vanadium (V), cadmium (Cd), zinc (Zn), using multivariate statistical approach and Sr isotopic compositions. The results show varying degrees of contamination in the sediments for some PTMs, i.e., Sr (16.1-39.6 mg/kg), Rb (171-675 mg/kg), Mn (224-2520 mg/kg), Li (11.6-78.8 mg/kg), Cd (0.31-1.38 mg/kg), and Zn (37.1-176 mg/kg). Multivariate statistical analyses indicate that Sr, Rb, Li, and Mn originated from the uranium tailing dam, while Cd and Zn were associated with abandoned agricultural activities, and Ni, Cu, and V were primarily linked to natural bedrock weathering. The Sr isotope fingerprint technique further suggests that 48.22-73.84% of Sr and associated PTMs in the sediments potentially derived from the uranium tailing dam. The combined use of multivariate statistical analysis and Sr isotopic fingerprint technique in alpine creek sediments enables more reliable insights into PTMs-induced pollution scenarios. The findings also offer unique perspectives for understanding and managing aqueous environments impacted by nuclear activities.

Geostatistical appraisal of water quality, contamination, source distribution of potentially toxic elements (PTEs) in the lower stretches of Subarnarekha River (Odisha), India, and health risk assessment by Monte Carlo simulation approach

In the present study, the status of water quality, environmental contamination in the lower stretch of Subarnarekha River with respect to potentially toxic elements (PTEs), its seasonal distribution, and ecotoxicological health impacts were investigated. For this purpose, a combination of indexing approaches and geospatial methods was used. The estimated water quality index (WQI) has shown that the river water falls under "moderate to very poor" category during the pre-monsoon and "moderate to poor" category in the post-monsoon season. The abundance of PTEs (Pb, Cu, Ni, Cd, Fe, and Cr) was on the higher side during the pre-monsoon in comparison with the post-monsoon season. The results of contamination index (Cd) and heavy metal evaluation index (HEI) explain that Subarnarekha River has low-to-moderate levels of contamination with PTEs in the majority of sampling sites. However, HPI indicated that the river water is moderate-to-highly contaminated with PTEs in both seasons. Principal component analysis (PCA) and cluster analysis (CA) reveal that anthropogenic sources are prime contributors to PTEs contamination in Subarnarekha River. The potential non-cancerous health concerns for child and adults due to Cr and Pb in some sampling stations along the river stretch have been observed. The carcinogenic risk (CR) has been established for Cr, Pb, and Cd in Subarnarekha River with Cr (> 10-4) as the most unsafe element. Monte Carlo simulation (MCS) indicates a high risk of cancer hazards due to Cr (values > 1E-04) in present as well as future for both child and adults.

Environmental effects from petroleum product transportation spillage in Nigeria: a critical review

Nigeria has struggled to meet sustainable development goals (SDGs) on environmental sustainability, transportation, and petroleum product distribution for decades, endangering human and ecological health. Petroleum product spills contaminate soil, water, and air, harming humans, aquatic life, and biodiversity. The oil and gas industry contributes to environmental sustainability and scientific and technological advancement through its supply chain activities in the transport and logistics sectors. This paper reviewed the effects of petroleum product transportation at three accident hotspots on Nigeria highway, where traffic and accident records are alarming due to the road axis connecting the southern and northern regions of the country. The preliminary data was statistically analysed to optimise the review process and reduce risk factors through ongoing data monitoring. Studies on Nigeria's petroleum product transportation spills and environmental impacts between the years 2013 and 2023 were critically analysed to generate updated information. The searches include Scopus, PubMed, and Google Scholar. Five hundred and forty peer-reviewed studies were analysed, and recommendations were established through the conclusions. The findings show that petroleum product transport causes heavy metal deposition in the environment as heavy metals damage aquatic life and build up in the food chain, posing a health risk to humans. The study revealed that petroleum product spills have far-reaching environmental repercussions and, therefore, recommended that petroleum product spills must be mitigated immediately. Furthermore, the study revealed that better spill response and stricter legislation are needed to reduce spills, while remediation is necessary to lessen the effects of spills on environmental and human health.

Contamination Assessment and Potential Human Health Risks of Heavy Metals in Urban Soils from Grand Forks, North Dakota, USA

Heavy metal (HM) pollution of soil is an increasingly serious problem worldwide. The current study assessed the metal levels and ecological and human health risk associated with HMs in Grand Forks urban soils. A total 40 composite surface soil samples were investigated for Mn, Fe, Co, Ni, Cu, Zn, As, Pb, Hg, Cr, Cd and Tl using microwave-assisted HNO3-HCl acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The enrichment factor (EF), contamination factor (CF), geoaccumulation index (Igeo), ecological risk and potential ecological risk index were used for ecological risk assessment. The park soils revealed the following decreasing trend for metal levels: Fe > Mn > Zn > Cr > Ni > Cu > Pb > As > Co > Cd > Tl > Hg. Based on mean levels, all the studied HMs except As and Cr were lower than guideline limits set by international agencies. Principal component analysis (PCA) indicated that Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, Cr and Tl may originate from natural sources, while Hg, Pb, As and Cd may come from anthropogenic/mixed sources. The Igeo results showed that the soil was moderately polluted by As and Cd and, based on EF results, As and Cd exhibited significant enrichment. The contamination factor analysis revealed that Zn and Pb showed moderate contamination, Hg exhibited low to moderate contamination and As and Cd showed high contamination in the soil. Comparatively higher risk was noted for children over adults and, overall, As was the major contributor (>50%), followed by Cr (>13%), in the non-carcinogenic risk assessment. Carcinogenic risk assessment revealed that As and Cr pose significant risks to the populations associated with this urban soil. Lastly, this study showed that the soil was moderately contaminated by As, Cd, Pb and Hg and should be regularly monitored for metal contamination.

Contamination level, source identification and health risk evaluation of potentially toxic elements (PTEs) in groundwater of an industrial city in eastern India

The present investigation explores the spatial and seasonal variations in potentially toxic element (PTEs) concentrations and contamination level assessment of groundwater samples in and around the Asansol industrial city, eastern India. The representative samples of groundwater from 24 different locations were analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH) and PTEs, e.g., Pb, Cu, Cd, Zn, Fe and Cr for pre-monsoon and post-monsoon. The pH level of examined groundwater samples is under the desirable limit with few exceptions (S5, S11 and S16 in pre-monsoon and S12 in post-monsoon). The recorded values for Pb, Cd, Fe and Cr in many sampling stations found higher than the prescribed limits of Indian standards (IS 10500: 2012) in both the seasons. The mean contamination factor (C_f) for PTEs in the groundwater is in the order of Cr > Fe > Cd > Pb > Cu > Zn and Fe > Cr > Cd > Pb > Cu > Zn, with mean contamination index (C_d) value of 2.83 and 2.72 in pre-monsoon and post-monsoon season, respectively, indicating moderate level of contamination in the examined area. Geospatial depiction of HPI values shows high level of contamination during pre-monsoon (58.3% sampling sites) and post-monsoon (45.8% sampling sites) in majority of sampling sites. Further, application of multivariate statistical analysis ascertains that the PTEs in groundwater are majorly derived from anthropogenic activities such as opencast mining, thermal power plants, iron and steel industries, sponge iron and other metallurgical industries, and leachate from urban and industrial wastes along with limited contribution from geogenic and lithogenic sources. The health risk assessment demonstrates that the non-carcinogenic risk (due to PTEs) in adults is in the sequence of Cr > Cd > Pb > Fe > Cu > Zn, while for children the order is Cr > Pb > Cd > Fe > Cu > Zn for both the seasons. The results also reveal higher chance of occurrence of carcinogenic risk due to Cr (ILCR > 1.0E-04) for children and adults in both the seasons.

A study on water pollution scenario of the Damodar river basin, India: assessment of potential health risk using long term database (1980-2019) and statistical analysis

The present work deals with a detailed study of India's Damodar river basin's pollution profile (groundwater, surface water, industrial water, and mine water). The present paper aims to create a large data bank comprising the latest (2019; through water sampling and analysis) and historical (1980-2018; through literature survey) data on heavy metal loads (HML) and other hydrochemical parameters in water bodies of the Damodar basin (at 99 sampling locations). Bivariate and multivariate statistical analyses were applied to determine the possible sources of the HML in the groundwater and surface water. Anthropogenic inputs from industrial effluents and mining activities were identified as the sources of the HML. The degree of HML exposure (Fe, Cu, Zn, Mn, As, Co, Cd, Hg, Cr, Ni, and Cu) was considered for computing the heavy metal pollution indices (HMPI). Associated potential health risk to the local population was also studied. Most HMPIs (vary within 50-9000) appeared to cross the critical value (~ 100). According to the results of noncarcinogenic risk, most hazard indices (varied within 0.01-116.34) surpassed the allowable limit (~ 1), demonstrating detrimental health effects on adults and children. Ni, Cd, As, and Cr showed very high cancer indices (varied within 9.5 × 10^-5-1.76 × 10^-1) that could be considered as high risk (≫ 1 × 10^-4, allowable limit) for cancer via ingestion and dermal pathways. A carcinogenic risk assessment map of the basin was also prepared for the first time. Durgapur and Burnpur-Asansol cities have been identified as the most vulnerable areas. The authors also compared the water quality parameters of the Damodar river with other highly polluted and major rivers of India. The authors recommended (i) strict regulation and efficient management of HML monitoring, (ii) initiating public awareness programme about Damodar's pollution, and (iii) a detailed medical survey to understand the impact of water pollution on the population.

Distribution and human health hazard appraisal with special reference to chromium in soils from Peenya industrial area, Bengaluru City, South India

Purpose

Presence of heavy metals in Peenya industries is considered a major environmental and human health risk. The purpose of this research is to determine the concentrations of trace elements in urban industrial soils in north Bengaluru in order to assess the degree of soil pollution and to evaluate environmental and human health risk.

Methods

Twelve soil samples during July-2016 were taken from Peenya industrial sites at different depth viz., 0-Hft., 1-3 ft., and 3-5 ft. heavy metals (As, Cd, Co, Cr⁺³, Cu, Fe, Mn, Pb, Sr, V, and Zn) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Contamination Factor, Enrichment Factor, Pollution Index, Modified Pollution Index, indices of pollution, Toxic Unit (TU), Hazard Quotient (HQ), Hazard Index (HI), Total Hazard Index (THI), Cancer Risk (CR), and Lifetime Cancer Risk (LCR) were used to evaluate the environmental and potential health hazard risks of human beings.

Results

Results showed that Cr⁺³ concentration exceeded the threshold limit of 60 mg/kg and 66.66%, 50%, and 41.66% showing more than the threshold limit at 0-1 ft., 1-3 ft. and 3-5 ft. depth soil samples. Single pollution indices showed that the study site was contaminated with chromium concentration. Nemerow pollution index showed that majority of soil samples were in the very high level of pollution. THI values showing <1 indicating that there were non-carcinogenic risks for children and less risk for adults. Based on LCR for children, 100% of soil samples were at high risk. LCR for Cr⁺³ concentrations of the soils were found higher than the threshold value of 1.00E-04, indicating a significant carcinogenic risk.

Conclusions

The study area is polluted, mainly with Chromium, whereas environmental risk is limited to a small part of it. This study can be used as a reference point to develop future long-term risk assessment plans on the probable movement of heavy metals in urban soils to human beings.

Geochemical Characteristics and Ecological Risk Assessment of Heavy Metals in Surface Soil of Gaomi City

Gaomi City, the hinterland of Jiaolai Plain in Shandong Peninsula, was selected as the research object. A total of 8197 surface soil samples were collected to determine the contents of eight soil heavy metals (HMs)including Copper (Cu), Lead (Pb), Zinc (Zn), Nickel (Ni), Chromium (Cr), Cadmium (Cd), Arsenic (As), and Mercury (Hg). Statistical methods were used to find out the geochemical background (GCB) in the area, systematic clustering and factor analysis were used to study the homology between HMs, and single-factor evaluation method was used to evaluate the ecological risks in the study area. The results of the study show that the ecological risk of the surface soil in the study area is relatively low, dominated by a planar distribution, with only a few high-risk points. The uneven distribution of Hg in the surface soil is affected by human activities to a certain extent. The ratio of the GCB of the geological unit area to the GCB of the whole area shows that the Hg content of the Qingshan Group and Dasheng Group geological units is higher, and the Pb content in the subvolcanic rock area is slightly higher. The ecological pollution risk in the study area is generally low, and only exists individual high-risk areas, distributed radially in densely populated areas.