Total Carcinogenic Risk Research Articles

Health Risk Assessment for an Arsenic-contaminated Site Based on Monte Carlo Simulation and Parameters Optimization

Risk assessment is a critical part of risk management for contaminated sites. However， in the specific management practice of As-contaminated sites， it is difficult to obtain realistic health risks for contaminated sites based on the total amount of pollutants and determined values of the model， thus preventing the control requirements of later remediation to be met. An increasing number of studies have recently been conducting risk assessments by considering bioavailability， modification parameters， and combined probabilistic models. To improve the accuracy of risk assessment results， taking a large As-contaminated site as a case， 432 sampling sites were set up and collected at different depths to analyze the level and distribution characteristics of As pollution， and probabilistic risk assessment was conducted with the modification of model parameters through literature research and Monte Carlo simulation. Then， the impact of traditional methods and probabilistic methods on health risk assessment was explored in comparison. The results indicated that ω（As） in the top soil of the study area ranged from 2.70-97.0 mg·kg-1， with a spatial variation coefficient of 0.61 and weaker spatial continuity. The carcinogenic risk and hazard index obtained by the traditional risk assessment method were 2.12E-4 and 8.36， respectively， which obviously overestimated the actual risk level and were not conductive to the refined management of As-contaminated sites. Combined with modification of model parameters and probabilistic risk assessment， the non-carcinogenic risk for adults and children was found to be at an acceptable level， and the carcinogenic risk was reduced by nearly an order of magnitude compared to that in the conventional method. Considering the relative biological effectiveness （RBA） of As， the 95% quantile of the total carcinogenic risk was 1.24E-5， a reduction of up to 36.41% compared to the uncorrected corresponding risk value of 1.95E-5. The carcinogenic risk of soil As for adults and children in the study area exceeded acceptable risk levels 1E-6， with oral ingestion of soil being the primary route of exposure. In addition， the results of the sensitivity analysis of the parameters showed that As concentration， daily oral ingestion rate of soils， and exposure duration of children had relatively larger effects for health risks. This work will provide a methodological and theoretical basis for achieving accurate risk assessment of As-contaminated sites and provide concepts for refined risk management.

Spatial Distribution, Risk Assessment and Sources of Heavy Metals in Roadside Soils Exposed to the Zhengzhou-Kaifeng Intercity Railway in Huanghuai Plain, China

ABSTRACT Heavy metal accumulation in soil can seriously harm human health, and it is necessary to identify the accumulation status and access the potential risks for local pollution control and sustainable economic development. This study evaluated the pollution level, spatial distribution, potential risk and sources of soil heavy metals along the Zhengzhou-Kaifeng intercity railway and compared pollution characteristics in north side soils with south side soils of the railway. A total of 260 soil samples were collected from a section along the railway. In practice, only the average Zn and Pb contents in soils were slightly higher than their corresponding risk screening values. The heavy metal enrichment in the north side soils was marginally lower than that in the south side soils. The spatial distribution of soil heavy metals except Pb could be mainly influenced by the different land use types. The geoaccumulation index and potential ecological risk of a single heavy metal indicated that Cd was the major contaminant with moderate pollution and high ecological risks in the south side soils and none to moderate pollution and moderate ecological risks in the north side soils. However, the mean multimetal potential ecological risk values suggested that the north side soils were at low ecological risks and the south side soils were at moderate ecological risks. The comprehensive non-carcinogenic risks and total carcinogenic risks for adults were low and acceptable, respectively. Pearson correlation analysis, PCA, and APCS-MLR analyses identified that the contributions of natural sources, mixed sources of industrial and traffic activities, agricultural activities, and other sources were 57.49%, 21.44%, 12.67% and 8.40%, respectively, and the major soil pollution Cd was mainly related to mixed sources of industrial and traffic activities. Therefore, continuous soil heavy metal monitoring is essential to elucidate the long-term railway operation effect on soil heavy metal accumulation.

Occurrence of BTX and PAHs in underground drinking water of coking contaminated sites: Linkage with altitude and health risk assessment by boiling-modified models

The safety of underground drinking water has received widespread attention. However, few studies have focused on the occurrence and health risks of pollutants in underground drinking water of coking contaminated sites. In this study, the distribution characteristics, sources, and human health risks of benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) in underground drinking water from a typical coking contaminated site in Shanxi of China were investigated. The average concentrations of BTX and PAHs in coking plant (CP) were 5.1 and 4.8 times higher than those in residential area (RA), respectively. Toluene and Benzene were the main BTX, while Acenaphthene, Fluorene, and Pyrene were the main PAHs. Concentrations of BTX/PAHs were negatively correlated with altitude, revealing altitude might be an important geological factor influencing spatial distribution of BTX/PAHs. PMF model demonstrated that the BTX/PAHs pollution in RA mainly originated from coking industrial activities. Health risk assessments were conducted by a modified US EPA-based model, in which environmental concentrations were replaced by residual concentrations after boiling. Residual ratios of different BTX/PAHs were determined by boiling experiments to be 9.4–93.8 %. The average total carcinogenic risks after boiling were decreased from 2.6 × 10−6 to 1.4 × 10−6 for adults, and from 4.3 × 10−6 to 2.1 × 10−6 for children, suggesting boiling was an effective strategy to reduce the carcinogenic risks from BTX/PAHs, especially for ingestion pathway. Monte Carlo simulation results matched well with the calculated results, suggesting the uncertainty was acceptable and the risk assessment results were reliable. This study provided useful information for revealing the spatial distribution of BTX/PAHs in underground drinking water of coking contaminated sites, understanding their linkage with altitude, and also helped to more accurately evaluate the health risks by using the newly established boiling-modified models.

Assessment of Heavy Metal Pollution and Health Risks in a Government-Intervened Electronic Waste Dismantling Area in South China

ABSTRACT Efficient control of heavy metal pollution necessitates a comprehensive understanding of pollutant sources. In this study, we conducted a thorough investigation of 11 metals in the soil of an electronic waste (e-waste) recycling facility in South China. The sources of these metals were determined through a combination of statistical analysis and the UNMIX model. Despite government intervention, our findings reveal significant pollution of nickel, copper, zinc, cadmium, and lead in the study area. Primary contributors to heavy metal contamination in the soil were identified as demolition activities, transport emissions, and atmospheric deposition. Utilizing a source risk assessment model, we observed that children face higher noncarcinogenic and carcinogenic risks compared to adults. Remarkably, the total hazard index of the study area was found to be considerably lower than that of other e-waste dismantling cities. Moreover, the total carcinogenic risk was noted to be one order of magnitude lower than both other e-waste dismantling cities and industrial and mining cities. While acknowledging the government’s commendable achievements in the standardized management of e-waste dismantling activities, our study underscores the need for targeted measures to further reduce pollution and safeguard the health of residents. These results emphasize the importance of ongoing efforts to enhance environmental protection strategies and underscore the significance of tailored interventions for sustainable pollution control in e-waste recycling facilities.

Human health risk assessment model associated with PM2.5 bound metals in paradip port township, India

This study aimed to assess the environmental risk and human health risks associated with PM2.5-bound metals in Paradip city between January 2019 and December 2021. The seasonal average concentrations of PM2.5 were measured 91.43 ± 70.18 μg m−3, 103.40 ± 60.80 μg m−3, 124.74 ± 62.37 μg m−3, and 159.37 ± 77.88 μg m−3 in pre-monsoon, monsoon, post-monsoon, and winter season respectively. The highest and lowest concentrations are estimated in the winter and pre-monsoon season. Paradip city experienced tropical weather conditions with a hot and humid climate. The wind pattern shows that the predominant wind direction was observed from the south-south-west (SSW) direction. The metals in PM2.5 were analysed using an atomic absorption spectrophotometer (AAS) by air-acetylene flame using a hollow cathode lamp. The average metal concentration decreased in the order of Fe > Al > Zn > Pb > Cr > Mn > Ni > Cu > Co > Cd > As. The value of the geo-accumulation index (Igeo) was evaluated >1 for Cd, Fe, and Zn elements. The health risk assessment (HRA) results showed that non-carcinogenic risk (NCR) was higher through the inhalation route followed by ingestion and dermal contact. The cumulative NCR, which is expressed in terms of the hazard index (HI), is greater than 1 for infant (2.78E+00), child (2.53E+00), and adult (1.04E+00) via inhalation pathway. The total carcinogenic risk (TCR) for infants, children, and adults was estimated at 1.45E-04, 7.24E-05 and 1.25E-05, respectively, which exceeded the acceptable limit of 1.00E-06. Our comprehensive research plays an important role in both policymakers and relevant stakeholders for the preparation of city action plans concerning ambient air pollution, which can improve the air quality in and around Paradip city, India.

Human health risk exposure from suspected BTEX and HMs contamination of Manihot spp. from nearby remediated oil spill field in Niger Delta, Nigeria

BackgroundCrude oil related activities in the Niger Delta region has exposed the environment to various degrees of pollutants, including heavy metals (HMs) and BTEX (Benzene, Toluene, Ethylbenzene, m, p-xylene, and o-xylene). The study assessed the human health risk exposure to BTEX and HMs (Lead, (Pb), chromium (Cr), cadmium (Cd), Nickel (Ni), copper (Cu) and iron (Fe) from remediated oil spilled field. Soil and Cassava tubers were collected around the field and analysed through laboratory procedures using Atomic Absorption Spectrophotometry and Gas Chromatography Flame under ASTMD 4691 and USEPA 8260B for HMs and BTEX, respectively. ResultThe mean concentration of Pb, Cd, Cr, Ni, Fe and Cu in the soil was 0.234 mg/kg, 0.004 mg/kg, 0.299 mg/kg, 0.307 mg/kg, 1.552 mg/kg and 0.527 mg/kg respectively and the concentration exceeded the allowable limit of WHO. The mean concentration of BTEX in the soil and Cassava was 0.0419 mg/kg and 0.1603 mg/kg, respectively and trended as Toluene (0.016 mg/kg) > Xylene (0.011 mg/kg) > Benzene (0.007 mg/kg) > Ethylbenzene (0.007 mg/kg) in soil and Ethylbenzene (0.057 mg/kg) > Xylene (0.051 mg/kg) > Benzene (0.034 mg/kg) > Toluene (0.02 mg/kg). The human health risk based on the target hazard quotient (THQ) for non-carcinogenic parameters in soil and Cassava ranged from “No Significant Risk of Non-Carcinogenic-NSRNc (THQ x 10-6) to Moderate Significant Risk of Non-Carcinogenic- MSRNc (THQ × 10-3)” for adults and children. The total carcinogenic risk (TCR) of the HMs and BTEX in soil and Cassava for adults and children was within the “Negligible Carcinogenic Risk for Human-ACRH (TCR × 10-6 to TCR × 10-9)”. ConclusionContinuous consumption and bioaccumulation of Cassava means the population are not entirely free from the risk of health exposure to BTEX and heavy metals; therefore, effective environmental sustainability practices must be encouraged.

Ecotoxicological status, source apportionment and human health risk assessment of potential toxic element in surface water and sediments of creeks along Bonny River, Nigeria

Potentially toxic elements (PTEs) are naturally available in the environment; however, anthropogenic activities encourage their high concentration, posing environmental and human health risks. The ecotoxicological status, source apportionment and health risk assessment of PTEs (Iron (Fe), Nickel (Ni), Cadmium (Cd), Selenium (Se), Zinc (Zn), Lead (Pb), Chromium (Cr) and Copper (Cu)) in creeks (Fibiri and Iwoama) along Bonny River were examined through laboratory analysis (American Public Health Association standard), indicators and statistical techniques. The PTEs concentration of surface water and sediment for both creeks exceeded the WHO allowable limit, and the surface water trended as Cr > Pb > Fe > Ni > Cd > Zn > Cu > Se for Fibiri creeks, Fe > Cr > Pb > Ni > Cd > Zn > Cu > Se for Iwoama creek while the sediment trended as Fe > Pb > Ni > Cr > Zn > Cd > Cu > Se for both creeks. The contamination factor (CF) of the creek’s sediment showed low CF (Zn and Cu), moderate CF (Ni, Pb and Cr) and very high CF (Fe and Cd), while risk index status ranged from low risk (Ni, Zn, Pb, Cr and Cu), moderate risk (Fe) and significantly high risk (Cd). The human health risk revealed that children could be exposed to potential non-carcinogenic effect (HI > 1) with Zn (1.64 and 2.03), and the Total Carcinogenic Risk (TCR) for children indicated high carcinogenic risk (TCR > 1 × 10−4) for Ni, Pb, Cr and Cd of the creeks’ environmental mediums. The similarity in the trend and status of the creeks suggested that both environments are exposed to similar anthropogenic activities impact.

Significance of Volatile Organic Compounds to Secondary Pollution Formation and Health Risks Observed during a Summer Campaign in an Industrial Urban Area.

The chemical complexity and toxicity of volatile organic compounds (VOCs) are primarily encountered through intensive anthropogenic emissions in suburban areas. Here, pollution characteristics, impacts on secondary pollution formation, and health risks were investigated through continuous in-field measurements from 1-30 June 2020 in suburban Nanjing, adjacent to national petrochemical industrial parks in China. On average, the total VOCs concentration was 34.47 ± 16.08 ppb, which was comprised mostly by alkanes (41.8%) and halogenated hydrocarbons (29.4%). In contrast, aromatics (17.4%) dominated the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) with 59.6% and 58.3%, respectively. Approximately 63.5% of VOCs were emitted from the petrochemical industry and from solvent usage based on source apportionment results, followed by biogenic emissions of 22.3% and vehicle emissions of 14.2%. Of the observed 46 VOC species, hexachlorobutadiene, dibromoethane, butadiene, tetrachloroethane, and vinyl chloride contributed as high as 98.8% of total carcinogenic risk, a large fraction of which was ascribed to the high-level emissions during ozone pollution episodes and nighttime. Therefore, the mitigation of VOC emissions from petrochemical industries would be an effective way to reduce secondary pollution and potential health risks in conurbation areas.

Determination of metals in different tissues of Trachurus trachurus from the Marmara Sea and evaluation of their health risks

The present study aimed to determine the differences in metal levels of Aluminum (Al), Cadmium (Cd), Chromium (Cr), Copper (Cu), İron (Fe), Manganese (Mn), Nickel (Ni), Lead (Pb) and Zinc (Zn) between muscle and liver tissues of Trachurus trachurus, the correlation of metal accumulation in tissues with fish length and weight was examined. Health risks and nutritional adequacy were evaluated based on metal levels accumulated in fish muscle. The results demonstrated that fish liver accumulated higher metal levels than muscle. The investigation revealed that the majority of metals present in the tissues of the fish did not exhibit a significant correlation with their size (p>0.05). It can be concluded that fish are not an adequate source of these nutrients because their nutrient levels are below reference values. The fish were found to be nutrient deficient, as the levels of nutrients were below reference values. The estimated daily intakes of all metals accumulated in muscle were below reference doses. The target hazard coefficient and target hazard index values were less than 1. Lifetime carcinogenic risk values were below 10-4, and total carcinogenic risk values were within the acceptable range. Pb and Cd concentrations in muscle exceeded the tolerable limit. The daily amount of fish that could be consumed without non-carcinogenic health risk was 181 grams for Cd and 295 grams for Pb. The daily amount of fish that could be consumed without carcinogenic health risk was 1.21 grams for Cd and 231 grams for Pb.

Spatial and variety distributions, risk assessment, and prediction model for heavy metals in rice grains in China.

In this study, 6229 brown rice grains from three major rice-producing regions were collected to investigate the spatial and variety distributions of heavy metals in rice grains in China. The potential sources of heavy metals in rice grains were identified using the Pearson correlation matrix and principal component analysis, and the health risks of dietary exposure to heavy metals via rice consumption were assessed using the hazard index (HI) and total carcinogenic risk (TCR) method, respectively. Moreover, 48 paired soil and rice samples from 11 cities were collected to construct a predicting model for Cd accumulation in rice grains using the multiple linear stepwise regression analysis. The results indicated that Cd and Ni were the main heavy metal pollutants in rice grains in China, with approximately 10% of samples exceeding their corresponding maximum allowable limits. The Yangtze River basin had heavier pollution of heavy metals than the Southeast Coastal Region and Northeast Plain, and the indica rice varieties had higher heavy metal accumulation abilities compared with the japonica rice. The Cu, Pb, and Cd mainly originated from anthropogenic sources, while As, Hg, Cr, and Ni originated from both natural and anthropogenic sources. The mean HI and TCR values of dietary exposure to heavy metals via rice consumption ranged from 2.92 to 4.31 and 9.74 × 10-3 to 1.44 × 10-2, respectively, much higher than the acceptable range, and As and Ni were the main contributor to the HI and TCR for Chinese adults and children, respectively. The available Si (ASi), total Cd (TCd), available Mo (AMo), and available S (AS) were the main soil factors determining grain Cd accumulation. A multiple linear stepwise regression model was constructed based on ASi, TCd, AMo, and AS in soils with good accuracy and precision, which could be applied to predict Cd accumulation in rice grains and guide safe rice production in contaminated paddy fields.

Quantitative characterization of resident’ exposure to typical semi-volatile organic compounds (SVOCs) around a non-ferrous metal smelting plant

To comprehensively characterize residents’ exposure to major semi-volatile organic compounds (SVOCs), samples of indoor floor wipes, size-segregated airborne particles, gaseous air, food, and paired skin wipes were simultaneously collected from residential areas around a large non-ferrous metal smelting plant as compared with the control areas, and three typical SVOCs (including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and halogenated PAHs (HPAHs)) were determined. Comparison and correlation analysis among matrices indicated PAHs were the major contaminants emitted from metal smelting activities compared to HPAHs and PCBs, with naphthalene verified as the most important characteristic compound, and their accumulation on skin may be a comprehensive consequence of contact with floor dust and air. While patterns of human exposure pathways for the SVOCs were found to be clearly correlated to their vapor pressure, dermal absorption was the major contributor (51.1–76.3%) to total carcinogenic risk (TCR) of PAHs and HPAHs for surrounding residents, especially for low molecular weight PAHs, but dietary ingestion (98.6%) was the dominant exposure pathway to PCBs. The TCR of PAHs exceeded the acceptable level (1 × 10−4), implying smelting activities obviously elevated the health risk. This study will serve developing pertinent exposure and health risk prevention measures.

Origin, spatial distribution, sediment contamination, ecological and health risk evaluation of trace metals in sediments of ship breaking area of Bangladesh

Eleven trace metals (Cd, Cr, Fe, Mn, Cu, Ni, Co, Zn, As, Pb, and Ag) in sediments of Bangladesh’s ship breaking area were measured by an atomic absorption spectrometer to determine origin, contamination extent, spatial distributions, and associated ecological and human health hazards. This study found considerable quantities of Pb, Cd, Mn, Zn, and Cu when compared with standards and high levels of Pb, Cd, Zn, Cu, As, and Ag contamination according to pollution evaluation indices. Different indices indicate most of the sampling sites were highly polluted. However, spatial distribution maps indicate that trace metals were predominantly deposited in the northern and southern region. The ecological risk index revealed that Cd has the highest while Pb and As had moderate risk. Based on the health index values, Zn for both adults and children were higher than the safe limit while Mn, Pb, Cr, As, Fe, Cu, Ni, and Co for children were close to the threshold. The mean total carcinogenic risk values of Cr, As, and Ni for children and Ni for adults exceeded the permissible threshold. The cancer risk possibilities were further assessed using Monte Carlo simulation. Most trace metals have anthropogenic origins, which were attributed to ship breaking activities.

Health Risk Assessment of Occupational Exposure to Chemical Materials in a Combined-Cycle Power Plant

Background: This study aimed to evaluate the occupational exposure of workers at a combined-cycle power plant located in the southwestern region of Iran. The assessment focuses on the inhalation exposure route to workplace emissions. Methods: The primary locations for potential pollutant emissions were identified in close proximity to the areas where chemicals were introduced and utilized within the production process. Sulfuric acid, sodium hydroxide, ammonia, oil mist, toluene, hydrogen sulfide, hydrazine, and tetrachloromethane were measured and analyzed using the NIOSH standard. Dose-response assessment was estimated using inhalation unit risk (IUR) for cancer risks and reference concentration (RFC) and reference exposure levels (REL) for non-cancer risks. Risk assessment was performed based on the Environmental Health Hazard Assessment guideline. Results: The results showed that ammonia and toluene had the highest and lowest concentration of pollutants emitted in workplace, respectively. The inhalation of ammonia and sulfuric acid and their daily absorption were at high risk level (HQ>1). Other noncancerous compounds had HQ<1. While the hazard index (HI) for total non-cancer risks was 5.34E+01 (HI>1), it was likely to have non-cancerous risks. For carcinogenic risks, they were calculated to be 9.58E-03 and 5.47E-04 for hydrazine and tetrachloromethane, respectively. The total carcinogenic risk of the emissions was calculated at 1.01E-02, which was in the significant range (more than 10-4) (i.e. in the range of hazardous cancer effects). Conclusion: This study confirmed the presence of non-carcinogenic risks, while the quantity of cancer risks fell within the Significant range, indicating a potential for carcinogenic risks.

Effect of Partial Organic Fertilizer Substitution on Heavy Metal Accumulation in Wheat Grains and Associated Health Risks

The partial substitution of chemical fertilizers with organic manure is an important strategy for improving agricultural sustainability. However, its effect on heavy metal (HM) pollution and its potential risk to human health remain unclear. Therefore, a field study was conducted to evaluate the effects of partial organic fertilizer substitution (0, 10%, 20%, 30%, and 40%) on health risks posed by HMs, including Zn, Cu, Ni, Cd, Pb, As, and Cr. The results showed that organic fertilizer substitution significantly increased Cu, Cd, Pb, and As accumulations in the soil. The Zn, Cu, Pb, and As contents were significantly higher in grains grown under organic fertilizer substitution (40%) conditions. The HM contents in the soil and grains were below the safety threshold limits in all treatments. Furthermore, the health risk caused by the exposure to As, Cu, and Zn accounted for 86% of the hazard index (HI) value. The HI value was significantly greater at a substitution ratio of 40% than in the no-nitrogen fertilizer treatment. Ingestion of the wheat grains grown at substitution ratios ≥ 30%) increased the carcinogenic risk of As and the total carcinogenic risk. In conclusion, organic fertilizer substitution at high ratios significantly increased the non-carcinogenic and carcinogenic risks associated with ingesting wheat grain. The optimal organic fertilizer substitution ratio (20%) maintained crop yields and improved soil fertility without increasing the non-carcinogenic or carcinogenic risks to human health. These findings highlight the importance of understanding the impacts of optimal organic fertilizer management in wheat growing systems.

Seasonal variations of potentially toxic elements (PTEs) in drinking water and health risk assessment via Monte Carlo simulation and Sobol sensitivity analysis in southern Iran's largest city

The escalating concern over the presence and health implications of potentially toxic elements (PTEs) in drinking water has underscored the need for rigorous risk assessments. Our study aimed to quantify both the non-carcinogenic and carcinogenic health risks associated with exposure to selected PTEs—namely arsenic (As), chromium (Cr), and cadmium (Cd). Also, we evaluated ingestion and skin contact exposures to risks during summer and winter using metrics such as the hazard quotient (HQ), hazard index (HI), and cancer risk (CR) for children, adult males, and adult females. For all demographic groups and exposure pathways, the HQ values remain below the established safety threshold (HQ < 1). Notably, As consistently had the highest average HI value across children, male adults, and female adults. Seasonal variations were statistically significant (p < 0.05) for As and Cr, but not Cd. During the summer, the average total carcinogenic risks (TCR) from drinking water exposure were 7.61 × 10–6, 8.94 × 10–6, and 1.12 × 10–5 for children, male adults, and female adults, respectively. In the winter, these values were 1.18 × 10–5, 1.40 × 10–5, and 1.75 × 10–5, respectively. The fuzzy C-means clustering analysis provided insights into our dataset's Cr, Cd, and As distribution patterns. Results indicate that As, Cr, and Cd mean concentrations were below the World Health Organization health-based guidelines. The CR values for children and adults from drinking water exposure were slightly above or below the US Environmental Protection Agency’s standards. These findings can inform research and policy-making regarding the risk of PTEs in drinking water and highlight the need to monitor Shiraz water regularly.

Health risk assessment of exposure to benzene, toluene, ethyl benzene, and xylene in shoe industry-related workplaces.

Benzene, toluene, ethyl benzene, and xylene (BTEX) are prevalent pollutants in shoe industry-related workplaces. The aim of this study was to assess exposure to BTEX and their carcinogenic and non-carcinogenic risks in shoe-industry-related workplaces. This study was carried out at different shoe manufactures, small shoe workshop units, shoe markets, and shoe stores in Tabriz, Iran in 2021. Personal inhalation exposure to BTEX was measured using the National Institute for Occupational Safety and Health (NIOSH) 1501 method. Carcinogenic and non-carcinogenic risks due to inhalation exposure to BTEX were estimated by United States Environmental Protection Agency (U.S. EPA) method based on Mont Carlo simulation. Results showed that the concentrations of benzene and toluene were higher than the threshold limit value (TLV) in both gluing and non-gluing units of shoe manufactures. The total carcinogenic risk (TCR) due to exposure to benzene and ethyl benzene was considerable in all shoe industry-related workplaces. Also, the hazard index (HI) as a non-carcinogenic index was higher than standard levels in all shoe industry-related workplaces. Therefore, shoe industry-related workers are at cancer and non-cancer risks due to exposure to BTEX. Prevention measures need to be implemented to reduce the concentration of BTEX in shoe industry-related workplaces.

Determination of Soil Fertility Characteristics and Heavy Metal Health Risks Using the Camellia oleifera Planting Base in Guizhou Province, China

To clarify the soil nutrient status and identify the safety risks of heavy metals in Camellia oleifera planting regions, the integrated soil fertility status was assessed using the improved Nemero composite index method, weighted average method, and coefficient of variation (CV) method, and the impact of heavy metals in the soil on human health was evaluated with a health risk assessment model using the Qianyu C. oleifera planting base in Yuping County, Guizhou Province, as the study object. The results showed the following: (1) The soil pH levels were 4.12–6.17, with CV values of 0.04–0.66, and no significant differences were observed among the plots. The soil was rich in organic matter, alkali-hydrolyzed nitrogen, and available phosphorus, with a high total potassium content, total phosphorus content, and rapidly available potassium, indicating a high level of comprehensive soil fertility. (2) The total carcinogenic risk (CR) index of the arsenic (As), cadmium (Cd), and chromium (Cr) in the soil was 1.92 × 10−7, and among these elements, the CR index of the As was the highest (1.3–8.0 × 10−7), but all were below the highest acceptable level (10−6) recommended by the United States Environmental Protection Agency (USEPA). (3) The redundancy analysis (RDA) between the soil fertility and trace elements revealed that the soil organic matter content was positively correlated with the contents of lead (Pb), manganese (Mn), and Cr and negatively correlated with the contents of zinc (Zn), iron (Fe), Cd, mercury (Hg), As, and copper (Cu). The soil pH was positively correlated with the contents of Cr, Fe, and Cu and negatively correlated with the contents of Mn, Pb, Zn, Cd, Hg, and As. In the study area, the soil was slightly acidic with overall high fertility without any CR. The quality of the C. oleifera was degraded by soil acidification, but the slightly acidic soil facilitated the absorption of trace elements by C. oleifera. Soil acidification could be relieved by taking appropriate measures, such as the addition of biochar or CaCO3. This study determined the soil fertility of the Qianyu C. oleifera planting base and assessed the health risk of heavy metals in the soil, providing a theoretical reference for enhancing C. oleifera quality, preventing the excessive accumulation of soil heavy metals, and improving the soil in this planting base.

Human health risk assessment of toxic heavy metals in summer crops and vegetables: a study in Ilam Province, Iran.

The presence of toxic heavy metals (HMs) in agricultural crops ‎can be considered as a noteworthy threat for consumers. The aim of this study was to assess the content of HMs ‎(Pb, As, Cr, Cd, Co, Hg, and Ag) and their potential health risk in summer crops and vegetables (watermelon, cantaloupe, cucumber, melon, tomato, onion, ‎potato, raw and stewed vegetables) in Ilam province, Iran. Totally, 31 crop samples were collected from local farms during the 2019 harvest ‎season and the elements ‎ content were evaluated using inductively coupled plasma-mass spectrometry (ICP-MS). The non-carcinogenic health risk of HMs to the adults and children was estimated by Monte Carlo simulation method and target hazard quotients (THQs). In general, the results showed that the concentration of Cr in the studied ‎agricultural crops was higher than other HMs. As well as, the carcinogenic risk (CR) obtained for adults and children were more than the acceptable range for As. Also, CR for As in raw vegetable was the most (‎8.19E-1) and violated the threshold risk limit. The total carcinogenic risk of HMs in children was higher than that in adults. These results suggest that the agricultural crops were not safe for human consumption with potential risks associated. Due to the possible health effects of such products consumption, proper action should be taken to avoid chronic exposure, prevention of further pollution and consequent adverse health implications.

Status of heavy metals and metalloid concentrations in water resources and associated health risks in parts of Indo-Gangetic plain, India

Groundwater is a major source for the supply of water for drinking as well as supporting the industrial and irrigation demands in the urban and peri-urban regions of Shahjahanpur, Uttar Pradesh, India. However, the groundwater quality of the area is deteriorating due to rapid urbanization, industrialization and intensive agriculture. The present study investigates the heavy metal(loid)s pollution in surface and groundwater and the associated health risks to the inhabitants. The results revealed that most of the analyzed heavy metal(loid)s remained within the acceptable limits set by the Bureau of Indian Standards (BIS, 2012) except for As, Fe, Mn and Ni. The collective impact of heavy metals on water quality was assessed using heavy metal pollution index (HPI) which revealed low pollution in November 2018 and low to medium pollution in October 2021. Ficklin-Caboi plot indicates that metals fall in ‘low’ to ‘high’ classes and their mobility in 30% and 45% of groundwater samples in November 2018 and October 2021 respectively was comparatively higher in the aqueous phase due to slightly lower pH conditions. The evaluated Non-Carcinogenic Hazard Index (HI) was significantly higher than the threshold limit (>1) for children as compared to adults. Relatively higher hazard quotient of As over Fe, Mn and Ni revealed its maximum contribution to the hazard index. The total carcinogenic risk values also exceeded the prescribed acceptable limit (1 × 10−4) for children compared to adults. The greater vulnerability of children can be attributed to several factors such as higher water consumption per unit of body weight of children compared to adults; toxicokinetic differences, immature metabolic enzyme systems and clearance mechanisms that result in longer half-lives of contaminants. Overall, the study reveals an escalated concern regarding heavy metal(loid)s induced health risk and recommends the adoption of conventional techniques for the removal of these metals from water resources.

Heavy Metals Accumulation in Vegetables and Its Consequences on Human Health in the Areas Influenced by Industrial Activities.

The degradation of the environment due to numerous industrial practices has emerged as a major issue globally, particularly in a country like Bangladesh. The present study dispenses information about heavy metal (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) contamination in some frequently consumed vegetables, namely, ash pumpkin, potato, bitter gourd, buffalo spinach, snake gourd, and pointed gourd grown in an industrially prone location and their repercussion on consumers' health. Proton-induced X-ray emission (PIXE) technique was used as the major analytical tool to detect heavy metal concentrations. Mean concentration and the range of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb in vegetables were detected (4.81 ± 2.79, 2.43-10.94), (497.57 ± 258.08, 181.24-886.67), (644.49 ± 298.40, 179.56-998.78), (38.88 ± 14.31, 18.88-60.12), (58.11 ± 12.58, 42.55-84.79), (137.24 ± 48.37, 71.99-208.98), (123.31 ± 63.62, 49.97-256.09), (8.09 ± 2.69, 4.29-14.94), and (4.16 ± 2.95, 1.22-9.98) mg/kg (dry weight basis), respectively. An extreme level of heavy metal contamination in vegetable samples was notified regarding the estimated metal pollution index (MPI) and Nemerow pollution index (P) value, which underpinned the health risk values. The estimated hazard index (HI) value stipulated high risk in all varieties of vegetables regardless of age group and cadmium (Cd) was found as the major contributor. Concerning the carcinogenic risk index (CR) for single elements, the value of Co, Ni, and Cr was approximated far above the USEPA threshold risk limit (CR>1E-04). Moreover, total carcinogenic risk (TCR) for all varieties of vegetables exceeded the safety threshold value for both the age group and children, in particular, were found most vulnerable. The outshot of the present study divulged associated health risks for the population group by the heavy metals via dietary intake of vegetables.