Hazard Index Values Research Articles

Potentially toxic metals in Northeast Ethiopian agricultural soils: implications for Solanum lycopersicum (Tomato) production and human health.

Exposure to heavy metal-contaminated vegetables, irrigation water and agricultural soil is one of the most challenging environmental issues worldwide. This study aimed to evaluate the health effects of potentially toxic metals (PTMs) including Cr, Cd, Fe, Pb, Cu, Zn, and Co from agricultural soil, irrigation water, and tomato plants collected from the Abuarie irrigation site, Northeast Ethiopia. The samples were digested using acid digestion method, and its concentration was quantified using Inductively Coupled Plasma-Optical Emission Spectroscopy. The concentrations of PTMs in the soil, tomato, and irrigation water samples ranged from 49,020 ± 275 (Fe) to 11.85 ± 0.44 (Cd), 170 ± 1.98 (Fe) to 0.29 ± 0.006 (Cd) mgkg-1, and 0.24 ± 0.003 (Fe) to 0.025 ± 0.005(Ni)mgL-1 , respectively. The results revealed Zn, Ni, Cd and Cr in soil, all metals in tomato, and Cu, Ni, Cd and Pb in irrigation water sample were above the World Health Organization threshold values. Moreover, the separate and cumulative exposure to farm soil, irrigation water, and consumption of tomato were investigated using the hazard quotient (HQ) and hazard index (HI) values, respectively. The results revealed that individual exposure to each sample type did not have a significant impact on health (HQ < 1). However, simultaneous exposure to all of the sample types (soil, tomato and irrigation water) at the same time had a high likelihood of affecting health (HI > 1). The total carcinogenic concentrations of Cr, Cd, Ni, and Pb were greater than 1 × 10-4, revealing that farmers have a high probability of developing cancer during their lifetime. Minimizing simultaneous exposure to soil, tomato, and irrigated water for local people is highly recommended to prevent the risk of PTMs.

Bioavailability and toxicity of heavy metals and microplastics in shellfish (Meretrix lyrata): A preliminary study in the Bay of Bengal

Microplastics (MPs) and heavy metals (HMs) pollution pose significant environmental threats by accumulating in marine species, leading to potential health risks for marine life and humans consuming contaminated seafood. However, limited research has been conducted on the bioavailability and toxicity of MPs and HMs in the marine biota of the Bay of Bengal, Bangladesh. In this study, the bioavailability of some HMs (i.e., Ni, Pb, Cd, and Cr) and MPs in a common marine shellfish (Meretrix lyrata) of the Bay of Bengal having nutritional and economic importance, and their human health risks due to the consumption of M. lyrata mussels has been evaluated. The mean concentrations of Ni, Pb, Cd, and Cr in the samples were determined spectrophotometrically and found as 5.54, 45.65, 0.51, and 33.51 mg/kg, respectively, which are higher than the maximum permissible limit set by different national and international entities. This study revealed that the hazard index values for all samples were greater than unity, which indicated that the cumulative effect of all selected heavy metals may pose substantial health hazards. The target cancer risk for Pb and Ni was also significant (i.e., TR > 1.0E-04). On the other hand, MPs (mainly polyvinyl chloride and polyethylene) of different colors (7−8) and shapes (6.53–330 μm) were detected in 50 % of the total studied samples, which is alarming and will result in a potential health risk due to the consumption of the mussels. Therefore, the consumer should be careful to eat this selected mussel (M. lyrata) in their regular meal and the concerned authority should take proper steps to protect this natural species from heavy metal and MPs contamination.

Groundwater quality in high-sulfur coal mining region of India: Spatial distribution, source control, and health risk assessment

The groundwater quality in the vicinity of the Makum coalfield, renowned for its high-sulfur coal deposits, was investigated. The oxidation of sulfur in the coal generates acid mine drainage (AMD), a global environmental challenge that contaminates natural resources. The region's high sulfur coal content intensifies AMD formation, necessitating a comprehensive assessment of its impact on human health and the environment. This study analyzes the water quality parameters such as pH, EC, TDS, Na+, Ca+2, Mg+2, K+, HCO3‐, SO4−2, F−, Cl -, and NO3− in groundwater, findings concerning low pH levels (5.8) and fluoride concentration (0.15 mg/L) compared to standards. Groundwater chemistry was analyzed to identify the sources controlling water composition through Gibbs diagrams, Piper diagrams, and saturation indices. The Gibbs diagram shows that rock weathering is the crucial factor controlling groundwater chemistry, while the Piper diagram indicates Ca-Cl as the Principal water type. Additionally, an in-depth analysis of groundwater chemistry reveals that carbonate dissolution primarily occurs due to minerals like calcite, dolomite, and gypsum, findings supported by saturation indices. The present study yielded an average water quality index of 40.19, indicating excellent to good water quality in 51 out of 52 samples analyzed. The average hazard index values for adults and children were 0.60 and 0.58, respectively, indicating that 49 of 52 samples pose negative non-carcinogenic risks associated with nitrate and fluoride contamination. The irrigation indices, graphical representations such as the Wilcox and Doneen classification, and the USSL diagram elucidate the suitability for irrigation purposes. Moreover, the Principal Component Analysis identified the sources of ions as originating from geogenic processes and mining activities. The study stresses environmental assessments, health risk management, and sustainable practices for groundwater in high-sulfur coal mining areas.

Ecotoxicological, ecological, and human health risks of total carbohydrates and some inorganic pollutants on the Nile Delta region along the Egyptian Mediterranean Coast

This is one of few studies dealing with the potential impact of total carbohydrates (TCHO), and some inorganic pollutants (F, B, As, V, Se) on human health. Additionally, the latter pollutants toxicological and ecological effects on the Egyptian Mediterranean Coast, especially, the Nile Delta region, were investigated. Both F (0.18 ± 0.09 mg/g) and As (2.47 ± 5.39 μg/g) were of lower concentrations compared to previous reports. Values of all ecological and ecotoxicity indices, particularly, the risk quotient (RQ), showed that arsenic had the most adverse biological effects on three trophic levels (algae, invertebrates, and fish). Children and adults non-carcinogenic hazard index (HI) values were <1, revealing that sediments in the studied area would pose no risk to humans. However, arsenic carcinogenic risk (CR) values exceeded the maximum permissible limits, implying risk to children and adults. These findings could anticipate toxic impacts of polluted effluents on the Nile Delta region.

Source to Receptor: Assessing Health Risks from Heavy Metal Exposure in Mining Soils

This research quantifies the health risks associated with exposure to heavy metals in the Matjhabeng Local Municipality, a gold mining region in South Africa, utilising a deterministic source–pathway–receptor approach. This study uniquely integrates both non-carcinogenic and carcinogenic risk assessments across multiple heavy metals, providing a comprehensive perspective on health impacts in mining-impacted communities. The study measured concentrations of arsenic (As), cadmium (Cd), lead (Pb), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), selenium (Se), and zinc (Zn) in soil samples, with mean values found to be 3.2 mg/kg, 2.5 mg/kg, 45 mg/kg, 17 mg/kg, and 25 mg/kg for As, Cd, Pb, Co, and Cr, respectively. The deterministic assessment revealed minimal non-carcinogenic risks for ingestion across all demographics (HQ &lt; 1), while significant dermal risks were identified for Cd, Pb, Co, and Cr (HQ &gt; 1), particularly for the adult group. The inhalation pathway emerged as a critical exposure route, with HQ values ranging from 5 to 15 and chronic hazard index values significantly exceeding safe limits (CHI &gt; 5). The carcinogenic risk through inhalation notably surpassed the acceptable thresholds set by the United States Environmental Protection Agency (1 × 10−4 to 1 × 10−6), with a calculated lifetime cancer risk far exceeding the limit for As, Cd, Cr, Co, and Ni for both adults and juveniles. These findings underscore the urgent need for targeted risk mitigation strategies in the community to address the significant health risks posed by airborne heavy metal exposure.

Phthalate and DINCH metabolites in the urine of Hungarian schoolchildren: Cumulative risk assessment and exposure determinants

A human biomonitoring study was conducted to assess the exposure of Hungarian children aged 8–11 years to ten phthalate esters (PEs) and DINCH between 2017 and 2018. In addition to collecting urine samples from 262 participants, a questionnaire was completed by the parents or legal guardians to identify potential determinants of exposure.The highest geometric mean concentration was observed for MiBP, followed by MBP, cx- MEHP, OH-MEHP and MEP. Three out of the four DINCH metabolites were detected in more than 90% of the samples. The comparison of the urinary concentrations measured in this study with those observed in the DEMOCOPHES study revealed a significant decreasing trend in all PE metabolites investigated in both studies between 2011/2012 and 2017/2018. Different approaches were used to assess the health risks associated with the exposure to PEs and DINCH. Our results highlighted that the hazard index (HI) values were higher than 1 in 17.6% of the children when the human biomonitoring guidance values were applied. In contrast, less than 3% of the children had HI values exceeding 1 when other sources of reference values were used. By applying a safety factor of 10 for the risk assessment, 17.6–91.6% of the children were characterized by HI values higher than 0.1, indicating the need for risk reduction measures. Overall, DnBP, DiBP and DEHP were identified as the main drivers of the mixture risk. Although PEs and DINCH are ubiquitous contaminants, there are still inconsistencies and gaps in our understanding of the determinants of exposure. The results of the multivariate regression analysis showed significant associations between PE or DINCH metabolite concentrations and certain individual characteristics, use of personal care products, home and school environment and food and beverages consumption 24 h prior to sample collection.

Assessing heavy metal contamination and health risks in playground dust near cement factory: exposure levels in children

Heavy metals pose significant threats to human health, particularly children. This study aimed to assess heavy metal pollution in children's playgrounds using surface dust as an indicator and to ascertain the associated exposure levels and health risks. A total of one hundred twenty dust samples were collected from the surface of playground toys in areas surrounding the cement factory in Bursa, Türkiye, on precipitation-free days. The heavy metal content of the samples was analyzed using ICP-MS. The average total concentration of heavy metals ranged from 2401 to 6832 mg/kg across the sampling sites, with the highest values observed at PG4, PG3, PG2, and PG1, respectively. The most commonly detected heavy metals in the samples included Cr, Mn, Fe, Co, Cu, Zn, Pb, Cd, As, and Ni. Statistical analysis revealed significant positive correlations (p < 0.01) among Cr, Mn, Fe, Co, Cu, Pb, As, and Ni, with Cu and Pb also showing correlation (p < 0.05). PCA analysis identified three principal components explaining 79.905% of the total variance. The Hazard Quotient (HQ) and Hazard Index values for heavy metals were found to be below the safe threshold (HQ < 1). Quantitative techniques such as the geoaccumulation index and enrichment factor are used to determine pollution levels at the sampling sites. Overall, the results indicate that cement factories significantly contribute to heavy metal pollution, with observed values varying based on proximity to the emission source.

Aggregate risk assessment for multi-route exposure to hazardous chemicals caused by chemical accidents, with a focus on toluene

Chemical accidents significantly impact environmental and human health. However, studies investigating the impacts of such accidents have primarily focused on single-route exposures, potentially underestimating the extent of damage. This study aimed to conduct an aggregate risk assessment for multi-route exposure to hazardous chemicals to ensure systematic and rational management of the health impacts on residents exposed to chemical accidents, considering the behavior of a hazardous chemical from a chemical accident within environmental media. Drawing upon a real chemical accident that occurred in Siheung, Gyeonggi-do, in 2019, leakage of 500 L of toluene over an hour was assumed. Employing a multimedia environmental dynamics model, the time-dependent concentrations across various environmental media were calculated, and the average daily dose (ADD), hazard quotient (HQ), and hazard index (HI) for each exposure route included in the multi-route exposure assessment were derived. Health risks were deemed present if the calculated HQ and HI values exceeded the threshold of 1. The results indicated the highest ADD values among the 0–9 age group, with inhalation exposure registering the highest ADD across all exposure routes. However, no significant health risks were observed, with both HQ and HI values not exceeding 1. This aggregate risk assessment approach is proposed as an effective preliminary evaluation method for health impact assessments in areas affected by chemical accidents.Graphical

Determination of potentially toxic metals and natural radionuclides in airborne pollens produced different urban environments in Turkey and health risk assessment

ABSTRACT Air pollutants are associated with potentially toxic metals (PTMs) and natural and/or artificial radionuclides, which can pose a major threat to human and environmental health. Pollens can be utilized as a bioindicator to determine the level of air pollution in urban areas. In this study, the concentrations of PTMs and natural radionuclides in 35 airborne pollen samples of 22 species belonging to Pinaceae, Cupressaceae, Araucariaceae, Betulaceae, Salicaceae, and Oleaceae families grown in different urban areas in Turkey were determined using an energy-dispersive X-ray fluorescence spectrometry. For the first time, non-carcinogenic and radiologic health risk assessments for adults were done, estimating hazard index (HI) and annual effective dose (AED), respectively. The concentrations of Fe, Mn, Zn, Ti, Sr, Cu, Ni, Co, Cr, V and Pb analyzed in airborne pollen samples varied from 52.1 to 3078.0, 26.1 to 159.6, 15.6 to 199.7, 9.1 to 282.2, 1.0 to 128.4, 5.0 to 40.1, 5.4 to 23.6, <LD to 11.3, 1.6 to 26.6, <LD to 11.1 and <LD to 5.7 mg/kg, respectively. The average concentrations of K (2%), Th (1.3 mg/kg) and U (1.0 mg/kg) were converted into the activity concentrations (in Bq/kg) of 40K (595.8), 232Th (5.2) and 238U (11.8), respectively. All HI and AED values revealed a very low non-carcinogenic and radiological health risk due to exposure to all PTMs and radionuclides in the pollen samples studied.

Legacy and novel brominated flame retardants in outdoor settled dusts and pine needles in a megacity of Eastern China: Interpretation of plant uptake

Brominated flame retardants, considered emerging contaminants, are widespread and persist in the environment. This study investigated the contamination of legacy and novel brominated flame retardants in paired outdoor settled dusts and pine needles sampled from a megacity in the Eastern China. The measured total concentrations of PBDEs (∑27PBDEs) in outdoor settled dusts and pine needles were in the range of 77.4–345.2 ng/g dw and 20.7–120.0 ng/g dw, respectively, and equivalent ranges for novel brominated flame retardants (∑11NBFRs) were 25.7–1917.2 ng/g dw and 9.4–38.7 ng/g dw, respectively. BDE-209 and DBDPE dominated PBDEs and NBFRs profiles, respectively, in both dusts and pine needles. Outdoor settled dusts exhibited greater potentials to accumulate high-brominated PBDE homologues and EH-TBB while pine needles tended to accumulate low-brominated PBDE homologues, BTBPE and TBC. The plant uptake of BFRs was interpreted by McLachlan's framework on the assumption that the levels of BFRs in outdoor settled dusts and particle phase of air were positively correlated. The accumulation of PBDEs in pine needles was dominated by equilibrium partitioning between the vegetation and the gas phase when log KOA values <10 and by particle-bound deposition when log KOA values >13. However, NBFRs exhibited more complicated accumulation behavior. The predicted 50th percentile of the estimated daily intakes of ∑27PBDEs via outdoor settled dusts exposure for adults and children were 3.5 × 10−2 and 1.4 × 10−1 ng/kg body weight (bw)/day, respectively, and equivalent values for ∑11NBFRs were 1.6 × 10−2 ng/kg bw/day and 6.3 × 10−2 ng/kg bw/day, respectively. The calculated hazard index (HI) values were far <1, indicating exposure of BFRs via outdoor settled dust intake would not pose potential non-carcinogenic health risks to both adults and children.

Health Risk Assessment of Metal Contamination in Four Green Leafy Vegetables from Various Open Markets in Benghazi

This study analysed aluminium, essential metals (chromium, manganese, iron, nickel, copper and zinc), and toxic metals (lead and cadmium) in green leafy vegetables (arugula, mint, parsley, and spinach) obtained from various markets in Benghazi city. A flame Atomic Absorption Spectrometer was used to determine the metal contents. Hazard quotient (HQ) and hazard index (HI) calculations were employed to assess non-carcinogenic and carcinogenic risks associated with the metals in the vegetables. Results showed that aluminium was detected in only 50% of the samples. All vegetable samples contained manganese, iron, copper and zinc within the ranges of 1.072-6.87mg, 26.71-298.4mg, 1.00-3.45mg and 3.61-9.33mg per 1kg of vegetable dry weight, respectively. Nickel and chromium were found in 33% and 50% of the samples, respectively. Cadmium and lead were present in all samples except for two spinach and two parsley samples. The levels of essential metals in the samples were below the maximum allowable limits set by FAO-WHO regulations. However, the contents of nickel, cadmium and lead in some vegetable samples exceeded the maximum limits. The metal contents in the collected vegetables were mostly lower than reported results from previous international studies. The HQ and HI values for the analysed metals were all below unity, suggesting that the consumption of these selected vegetables as part of a daily diet poses no threat to human health.

The levels, single and multiple health risk assessment of 23 metals in enteral nutrition formulas

Enteral nutrition formulas are products that provide macro and micronutrients to patients who cannot receive their nutrition orally. In this study, the levels of 23 metals known to have potential health risks were determined by inductively coupled plasma mass spectrometry in a total of 28 enteral nutrition formula. Metal exposure was calculated according to three different daily energy intake scenarios (Scenario 1 = 50% oral nutrition + 50% enteral nutrition formula, Scenario 2 = 25% oral nutrition + 75% enteral nutrition formula and Scenario 3 = 100% enteral nutrition formula) and evaluated in terms of non-carcinogenic health risks. The mean levels of Fe, Co, Ni, Cu, Zn, Mo, Se, Li, Be, V, As, Sr, Ag, Cd, Sb, Ba, La, Hg and Pb in the samples analyzed were determined 12,000 ± 3300, 64 ± 1.6, 10 ± 13, 1300 ± 400, 8500 ± 2500, 75 ± 30, 61 ± 21, 0.34 ± 0.36, 0.05 ± 0.08, 7.3 ± 2, 1.6 ± 0.6, 457 ± 166, 0.02 ± 0.1, 0.14 ± 0.12, 0.01 ± 0.1, 74 ± 103, 0.63 ± 0.4, 0.05 ± 0.03 and 0.14 ± 0.7 μg/L. These metals were considered safe in terms of non-carcinogenic health risks when analyzed individually. However, when the target hazard quotient values of all metals were evaluated together, hazard index values were higher than the reference value of 1, for both men and women, indicating potential health risks.

Water recovery and treatment of spent filter backwash from drinking water using chemical reactor-ultrafiltration process

During routine operations of water treatment plant (WTP), production of spent filter backwash water (SFBW) is inevitable that imposes high operation and maintenance costs. The study investigates treatment and water recovery from SFBW from WTP via combined chemical reactor-ultrafiltration (CR-UF) process. The daily generated SFBW from full-scale treatment plants were treated by the pilot pant of CR-UF process, which is comprised of a primary sedimentation basin, coagulation and flocculation tank immersed UF membrane module. The optimum conditions for CR process were pH 7.5 and FeCl3 dose 20 mg/L, which led to significant removal of turbidity, color, and UV254 that are equal to 97.11 ± 0.10 %, 63.31 ± 1.98 %, and 30.74 ± 0.72 %, respectively. The CR-UF produced permeate with very low turbidity (0.3 ± 0.01 NTU and 93.0 ± 1.1 % removal) has met the water standard of 5 NTU. During the continuous operation of CR-UF process and after three consecutive cycles of UF backwashing, initial flux slightly declined from 8.57 L/m2.h in the 1st cycle to 8.20 L/m2.h in the 3rd cycle, demonstrating the irreversible fouling due to nanoparticle blocking. In four proposed blending of SFBW, the amount of UV254 and TOC did not change significantly (<1 % increase), and additional coagulant was not needed. The hazard index (HI) values for all the population groups were <1, suggesting a minimal adverse health risk regarding the consumption of treated SFBW by the CR-UF process. Overall, the permeate stream of CR-UF process can be reused as a source of raw water for drinking water treatment plant.

Assessment of Human Health Risk Caused by Heavy Metals in Kiln Dust from Coal-Fired Clay Brick Factories in Türkiye

AbstractHeavy metal (HM) pollution from natural processes and different anthropogenic activities pose significant human and environmental health risks because of their stability, non-degradable properties, and high toxicity. HM released into the air in the form of dust can enter the human body via ingestion, inhalation, and dermal contact. Keeping in mind the significance of estimating the risk from HM in different environments, the carcinogenic and non-carcinogenic health risks to workers caused by HM in kiln dust (KD) samples collected from coal-fired clay brick factories in the Western Black Sea Region of Türkiye were assessed for the first time in this study. The concentrations of major and minor oxides and HMs in the collected KD samples were analyzed using energy-dispersive X-ray fluorescence spectrometry. The average concentrations of Fe, Mn, Cr, Ni, V, Zn, Cu, As, Co and Pb analyzed in thirty-three KD samples were determined as 65444, 768, 251, 249, 248, 122, 60, 52, 42 and 16 mg/kg dw, respectively. The average levels of Ni, As, Cr, Co and Cu exceed the maximum contaminant levels recommended in the Turkish Regulation on Control of Soil Pollution. Carcinogenic and non-carcinogenic human health risk assessments for workers via three exposure pathways were carried out, estimating the hazard index (HI) and total carcinogenic risk (TCR) index, respectively. The HI values (&lt; 1) revealed no possible non-carcinogenic health risk due to exposure to all HMs in the studied KD samples. The average TCR value revealed that the potential cancer risks for Ni, As, Cr, and Pb were slightly above the safe limit and required monitoring and further investigation for these HMs.

Advanced approach combines integrated weight water quality index and potential toxic elements for environmental and health risk assessment supported by simulation technique in Oued Souf, Algeria

The current research study evaluated the health and environmental risks issues associated with potentially toxic elements (PTEs) in the complex terminal aquifer located in the Algerian desert. The methods used included principal component and cluster (dendrogram) analysis to estimate source of ions and contamination. Various indices such as the Heavy Metal Pollution Index (HPI), Metal Index, hazard quotient, hazard index (HI), and cancer risk (CR) were applied to assess both environmental and human health risks. Furthermore, the Monte Carlo method was applied for probabilistic assessment of carcinogenic and non-carcinogenic risks through oral and dermal exposure routes in both adults and children. The results revealed that approximately 16% of the samples fell within the low pollution category (HPI < 100), indicating relatively lower levels of heavy metal contamination. However, the remaining 84% of the samples exhibited high pollution levels, indicating a significant presence of heavy metal pollutants in the northeastern part of the investigated area. The calculated average risk index (RI) for the collected samples was 18.99, with a range from 0.03 to 103.21. This indicates that a large portion, 82% of the samples, could cause low ecological risk (RI < 30), whereas the remaining 18% indicate a significant environmental pollution risk. The HI for oral ingestion showed that adults had HI values ranging from 0.231 to 1.54, while children exhibited higher values, ranging from 0.884 to 5.9 (Fig. 5a). For dermal exposure, HI values in adults ranged from 2.71E−07 to 8.74E−06 and in children, from 2.18E−06 to 7.03E−05. These findings highlight the potential non-carcinogenic risks associated with oral exposure to PTEs and underscore the increased vulnerability of children to metals such as Fe, Mn, Pb, and Cr. Most samples showed CR exceeding 1 × 10−4 for chromium (Cr) and lead (Pb), indicating a significant vulnerability to carcinogenic effects in both children and adults.

Health risk assessment and contamination of lead and cadmium levels in sediments of the northwestern Arabian Gulf coast

This environmental assessment focuses on the coastal sediments of the Al-Khafji area in the Saudi Arabian Gulf, with an analysis of the human health risks posed by lead (Pb) and cadmium (Cd) contamination. Single and integrated indices were used to detect contamination and evaluate these metals' non-carcinogenic and carcinogenic impacts on adults and children through ingestion, dermal contact, and inhalation pathways. Sediment quality guidelines and contamination indices indicated the absence of significant contamination levels. The moderate contamination observed in scattered samples did not imply adverse biological effects due to the presence of these two metals in Al-Khafji sediments. The average values of the chronic daily intake (CDI) for both Pb and Cd were higher in children than adults across all three pathways, with ratios of 9.4, 4.7, and 4.7 folds, respectively. The hazard index (HI) values for Pb and Cd were below 1, confirming that the sediments of Al-Khafji are considered acceptable and safe in terms of these potentially toxic elements (PTEs). The average lifetime cancer risk (LCR) values for Pb and Cd were higher in children compared to adults, with ratios of 9.3 and 9.4 folds, respectively. However, all detected LCR levels do not represent a potential carcinogenic health hazard. Nevertheless, a regular monitoring program aimed at detecting early signals of environmental health depletion is recommended.

Evaluation of ground water quality using heavy metal pollution indices and estimation of health risk

ABSTRACT This paper presents the monitoring of heavy metals, including cadmium (Cd), chromium (Cr), lead (Pb), copper (Cu), and zinc (Zn), in the groundwater of the Byrnihat Industrial Area and Guwahati City, which is located in close proximity to the Byrnihat Industrial Area. A total of 20 water samples were collected at distances approximately 1–2 km apart from each other. The pH and the TDS of the collected samples were analysed immediately after collecting samples using a digital pH and TDS meters. The collected samples were analysed using a Flame type Atomic Absorption Spectrophotometer. The highest observed values of Cd, Cr, Pb, Cu and Zn in mg/L were recorded to be 0.0526, 0.1438, 0.5175, 0.1060 and 0.0925, respectively. The average values of Cd, Cr, Pb, Cu and Zn were 0.0246 ± 0.0168 mg/L, 0.0282 ± 0.0421 mg/L, 0.4805 ± 0.0206 mg/L, 0.0653 ± 0.0276 mg/L, and 0.0642 ± 0.0098 mg/L, respectively. Cd and Pb concentrations were above the guideline values set by Bureau of Indian Standards (BIS) and the World Health Organisation (WHO) [WHO recommended values, Cd: 0.003 mg/L, Pb: 0.01 mg/L]. Though the average concentration of Cr was below the allowable limit, five samples within the Byrnihat industrial area were found to be above the limit. High values of pollution indices was observed for all the samples. The cumulative hazard index (HI) values for adults and children were found to be 8.56 and 9.37, respectively. The total cancer risk (TCR) was observed to be 7.87E-03 for adults and 8.54E-03 for children. The result obtained from the present investigation show significant contamination of ground water by heavy metals, particularly Pb, Cd, and Cr concentrations. The observed high values of hazard index and cancer risks indicate significant health risks, necessitating the need for immediate regulatory action.

Microbial electrochemical enhanced composting of sludge and kitchen waste: Electricity generation, composting efficiency and health risk assessment for land use

To realize the energy and resource utilization from organic solid waste, a two-phase microbial desalination cell (TPMDC) was constructed using dewatered sludge and kitchen waste as the anode substrate. The performance of electricity generation and composting efficacy was investigated, along with a comprehensive assessment of the potential health risks associated with the land use of the resulting mixed compost products. Experimental outcomes revealed a maximum open-circuit voltage of 0.893 ± 0.005 V and a maximum volumetric power density of 0.797 ± 0.009 W/m³. After 90 days of composting enhanced by microbial electrochemistry, a significant organic matter removal rate of 31.13 ± 0.44 % was obtained, and the anode substrate electric conductivity was reduced by 30.02 ± 0.04 % based on the anode desalination. Simultaneously, there was an increase in the content of available nitrogen, phosphorus, and potassium, as well as an improvement in the seed germination index. The forms of heavy metals shifted from bioavailable to stable residual states. The non-carcinogenic hazard index (HI) values for heavy metals and polycyclic aromatic hydrocarbons (PAHs) during the land use of compost products were less than 1, and the total carcinogenic risk (TCR) values for heavy metals and PAHs were below the acceptable threshold of 10−4. The occupational population risk of infection from five pathogens was higher than that of the general public, with all risk values ranging from 8.67 × 10−8 to 1, where the highest risk was attributed to occupational exposure to Legionella. These outcomes demonstrated that the mixture of dewatered sludge and kitchen waste was an appropriate anode substrate to enhance TPMDC stability for electricity generation, and its compost products have promising land use suitability and acceptable land use risk, which will provide important guidance for the safe treatment and disposal of organic solid waste.

Assessment of heavy metal contamination risk in dry fish from India: A comprehensive study

The widespread presence of heavy metal contaminants in aquatic ecosystems, and consequently in fish, has emerged as a paramount concern owing to the staple role of fish in the Indian diet. The present study addresses heavy metal contamination in dried fish consumed across India and its associated health risks. The objectives of this study were to determine the heavy metal concentrations in dried fish from different regions of India, assess daily heavy metal intake through dried fish consumption, and evaluate the carcinogenic and non-carcinogenic health risks associated with heavy metal exposure. Subsequently, 111 dried fish samples from Guwahati-Assam, Mumbai, Karad-Maharashtra, and Goa were analyzed for eight selected heavy metals using a validated inductively coupled plasma mass spectrometry method results indicated varying contamination levels across locations, with As being the most abundant heavy metal. In Maharashtra and Assam, the heavy metal load in dried fish was as follows: As > Cr > Ni > V > Cd > Pb > Co > Hg. For Goa, the order was As > Cr > Ni > V > Cd > Co > Pb > Hg. Dietary exposure assessments revealed varying levels of exposure between adults and children, with As and Cd posing higher risks to children. The Target Hazard Quotient (THQ) and Hazard Index (HI) values for all metals were within acceptable limit of one. Health risk assessments revealed generally low hazard levels for adults, but higher risks for children, particularly at higher percentiles. Furthermore, As was identified as posing a medium risk of cancer. In essence, this research emphasizes the necessity for strict monitoring and regulations with the aim of controlling health hazards related to heavy metal pollution in food sources.

Health Risk Assessment of Exposure to Heavy Metals in Wheat Flour from Iran Markets: Application of Monte Carlo Simulation Approach.

The significance of flour in the Iranian diet underscores the need to ensure its safety from chemical pollutants. This study aimed to evaluate the potential health risks posed by certain heavy metals, such as Fe, Zn, Cu, Al, Co, Hg, Cr, Ni, Pb, and Cd, in wheat flour available in the Iranian market. A total of 248 flour samples were collected from 11 provinces in Iran during the winter of 2021. The health risks associated with heavy metals in children and adults were evaluated using USEPA health risk assessment guidance for superfund part A and Monte Carlo Simulation. The average concentration of Fe, Zn, Cu, Al, Co, Hg, Cr, Ni, Pb, and Cd, was equal to 30.62 ± 59.24, 4.94 ± 13.64, 1.24 ± 3.08, 2.85 ± 4.98, 0.03 ± 0.01, 0.12 ± 0.03, 1.42 ± 1, 0.23 ± 0.05, 1.71 ± 0.65, and 0.02 ± 0.004mg/kg dry weight, respectively. Analysis of Fe, Cr, Al, Hg and Cr in all flour samples showed that the average concentration of these metals were greater than the standards levels set by the WHO/FAO. The results of the non-carcinogenic risks (HI) showed that the hazard index values (children: 0.969 ± 1.04, adult: 0.837 ± 0.905) of heavy metals through the consumption of flour to both study population were acceptable. The results of the carcinogenic risks (CR) based on Cd, and Pb concentration showed that the CR values from ingestion of flour to the children and adults population were 1.45 × 10-5 ± 5.08 × 10-5 and 1.26 × 10-5 ± 4.40 × 10-5, respectively. The results of Monte Carlo simulation showed that conventional deterministic health risk evaluation could overestimate risk outcomes. Likewise, Cr has 68.8% and 69.1% probability of non-carcinogenic risk to children and adult, respectively, and 80% and 79.8% probability of CR for adults and children respectively for Pb, suggesting that Cr and Pb is a priority control heavy metals. Therefore, it is recommended to continuously monitor the levels of heavy metals in wheat and its derived food products to ensure food safety.