Spatial distribution variation and probabilistic risk assessment of exposure to chromium in ground water supplies; a case study in the east of Iran

Numerical simulation application in occupational health studies: a review

Most occupational hazardous agents in workplaces should be evaluated and controlled. Different methods exist for identifying, evaluating and controlling these agents, such as numerical simulation tools. Numerical simulations can help experts to improve occupational health. Due to the importance and abilities of numerical simulations, this study divided occupational hazardous agents into 10 subgroups. These subgroups included air pollution, ventilation, respiratory airways, noise and vibration, lighting, radiation, ergonomics, fire and explosion, risk assessment and personal protective equipment. Recent research studies in each subgroup were then reviewed, and the codes and software used in simulations were determined. The results show that Fluent software and k-ϵ turbulence models are the most used in occupational health studies simulations. Today, different codes and software have been developed for simulation, and we suggest their use in occupational health studies.

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.

Coupling of radon and microbial analysis for dense non-aqueous-phase liquid tracing and health risk assessment in groundwater under seasonal variations

Dense non-aqueous-phase liquids (DNAPLs) represent one of the most hazardous contaminants of groundwater, posing health risks to humans. Radon is generally used to trace DNAPLs; however, external factors, such as rainfall or stream water, can influence its efficacy. To overcome these limitations, this study pioneered the integration of radon and microbial community structures to explore DNAPL tracing and natural attenuation in the context of seasonal variations for human health risk assessments. The results showed that a radon tracer can estimate DNAPL saturation in the source zone, especially during the dry season when radon deficiency predominates. However, samples exhibited mixing effects during the wet season because of local precipitation. Moreover, bioremediation and low health risks were observed in the plume boundary zone, indicating that microbial dechlorination was a predominant factor determining these risks. The abnormal patterns of radon observed during the wet season can be elucidated by examining microbiological communities. Consequently, a combined approach employing radon and microbial analysis is advocated for the boundary zone, albeit with a less intensive management strategy, compared with that for the source zone. This novel coupling method offers a theoretical and practical foundation for managing DNAPL-contaminated groundwater.

Employing a Toxic Aging Coin approach to assess hexavalent chromium (Cr[VI])-induced neurotoxic effects on behavior: Heads for age differences

We are facing a rapidly growing geriatric population (65+) that will live for multiple decades and are challenged with environmental pollution far exceeding that of previous generations. Consequently, we currently have a poor understanding of how environmental pollution will impact geriatric health distinctly from younger populations. Few toxicology studies have considered age differences with geriatric individuals. Critically, all top ten most prevalent age-related diseases are linked to metal exposures. Hexavalent chromium [Cr(VI)] is a metal of major environmental health concern that can induce aging phenotypes and neurotoxicity. However, there are many knowledge gaps for Cr(VI) neurotoxicity, including how Cr(VI) impacts behavior. To address this, we exposed male rats across three ages (3-, 7-, and 18-months old) to Cr(VI) in drinking water (0, 0.05, 0.1 mg/L) for 90 days. These levels reflect the maximum contaminant levels determined by the World Health Organization (WHO) and the U.S. Environmental Protection Agency (US EPA). Here, we report how these Cr(VI) drinking water levels impacted rat behaviors using a battery of behavior tests, including grip strength, open field assay, elevated plus maze, Y-maze, and 3-chamber assay. We observed adult rats were the most affected age group and memory assays (spatial and social) exhibited the most significant effects. Critically, the significant effects were surprising as rats should be particularly resistant to these Cr(VI) drinking water levels due to the adjustments applied in risk assessment from rodent studies to human safety, and because rats endogenously synthesize vitamin C in their livers (vitamin C is a primary reducer of Cr[VI] to Cr[III]). Our results emphasize the need to broaden the scope of toxicology research to consider multiple life stages and suggest the current regulations for Cr(VI) in drinking water need to be revisited.

A novel bioaccessibility-based probabilistic risks assessment of potentially toxic elements (PTEs) in earthworm

Introduction: Early risk assessment studies usually based on total heavy metal (loid) contents, inevitably leading to an overestimation of the health risks. In addition, inputs are represented as single-point estimates in deterministic models, leading to underestimation or overestimation of the health risks. Methods: To overcome these barriers, a novel probabilistic risk assessment strategy based on the combinational use of bioaccessibility and Monte Carlo simulation was developed to assess heavy metal (loid) associated health risks of earthworms in this study. To obtain a realistic and robust probabilistic risk assessment, heavy metal (loid) exposure duration and frequency were determined using our questionnaire data. Results: As a result, the mean gastrointestinal bioaccessibility was in the order: Cd > As > Cu > Hg. The mean hazard index (HI) values for investigated metal (loid)s were 0.65 and 0.59 for male and female, respectively, demonstrating an acceptable health risk in an average community. However, the 90th percentile of HI values was 1.87 and 1.65 for male and female, respectively. And the total non-cancer risks of heavy metal (loid) exposure exceeded the acceptable threshold for 19.9% and 17.8% of male and female, respectively. In addition, the total cancer risk (TCR) value through co-exposure to As and Cd suggested that the carcinogenic risks may be of concern for average exposure population. Sensitivity analyses revealed that the exposure frequency and bioaccessible As concentration were the dominant contributors to the total risk variance, which provided meaningful implications for environmental management. Conclusion: Altogether, the refined strategy based on bioaccessibility and Monte Carlo simulation is the first of its kind, such effort attempts to scientifically guide the rational clinic use of TCM and the improvement of population-health.

Carcinogenic and non-carcinogenic human health risk assessments of heavy metals contamination in drinking water supplies in Iran: a systematic review

The contamination of water due to heavy metals (HMs) is a big concern for humankind; particularly in developing countries. This research is a systematic review, conducted by searching google scholar, Web of Science, Science Direct, PubMed, Springer, and Scopus databases for related published papers from 2010 to July 2021, resulting in including 40 articles. Among the analyzed HMs in the presented review, the average content of Cr, Pb, Ba, Al, As, Zn, and Cd exceeded the permissible limits suggested by the World Health Organization (WHO) and 1,053 Iranian standards. Also, the rank order of Hazard Quotient (HQ) of HMs was defined as Cd>As>Cr>Pb>Li for children which means Cd has the highest non-carcinogenic risk and Li has the least. This verifies to the current order As>Cr>Pb>Fe=Zn=Cu>Cd for adults. The corresponded values of HQ and Hazard Index (HI) in most cities and villages were investigated and the results indicated a lower than 1 value, which means consumers are not at non-carcinogenic risk (HQ). Carcinogenic risk (CR) of As in the adult and children consumers in most of the samples (58.82% of samples for both groups) were investigated too, and it was more than>1.00E-04 value, which determines that consumers are at significant CR.

Pesticide residues in drinking water treatment plants and human health risk assessment: a case study from Northern Iran

These days, the presence of pesticide residues in drinking water sources is a serious concern. In drinking water treatment plants (DWTPs), various methods have been proposed to remove pesticide residues. This study was designed with the objectives of monitoring the occurrence and seasonal variations of pesticides in the output of drinking water treatment plants in two Northern provinces of Iran, Gilan and Golestan, and identifying their human health risks. Seventeen pesticide residues from different chemical structures were determined by using a gas chromatograph-mass spectrometer (GC-MS). The results showed that only Alachlor, Diazinon, Fenitrothion, Malathion, and Chlorpyrifos were detected. The pesticide concentrations ranged from ND to 405.3 ng/L and were higher in the first half-year period. The total non-carcinogenic human health risks was in safe range for infants, children, and adults (HI < 1). The carcinogenic human health risks of Alachlor for infants, children, and adults were in the range of 4.3 × 10-7 to 1.3 × 10-6, 2.0 × 10-7 to 9.6 × 10-7, and 1.1 × 10-7 to 5.5 × 10-7, respectively. These values do not pose health risks for adults and children, but may present a possible cancer risk for infants in two DWTPs of Golestan. In conclusion, considering the possibility of exposure to these pesticides through other routes, simultaneously, it is suggested to carry out a study that examines the level of risk by considering all exposure routes. We also propose stricter regulations for the sale and use of pesticides in Iran.

Different photoreduction processes of Cr(VI) on cellulose-rich and lignin-rich biochar

In this study, a series of biochar were prepared via pyrolyzing cellulose-rich pakchoi (PBC) and lignin-rich corncob (CBC) to explore the photoreduction process of Cr(VI). X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy confirmed higher oxygenated functional groups in PBC (48.9%-57.1%), whereas CBC exhibited more aromatization properties due to the stable aromatic network in lignin. For PBC, the valence bands decreased from 1.42 eV to 1.20 eV with the increase of pyrolysis temperature from 300 °C to 500 °C; however, an opposite trend was observed for CBC. The photoreduction of Cr(VI) clearly showed that both PBC and CBC had the best performance at the carbonization temperature of 300 °C (named PBC300 and CBC300). It is noted that PBC300 exhibited the most effective photoreduction of Cr(VI), which was about 1.3 times higher than that of CBC300. The maximum reduction capacities of Cr(VI) were 68.2 mg g-1 on PBC300 and 66.1 mg g-1 on CBC300 at pH∼2.0. Compared with the insoluble char substances, dissolved black carbons made more contributions for Cr(VI) photoreduction, ∼70% in PBC and almost 100% in CBC, which suggested that in the case of PBC, the insoluble char and the corresponding dissolved black carbons play an important role in the photoreduction of Cr(VI). However, only dissolved black carbons contributed to Cr(VI) photoreduction on CBC. As the key reaction pathway, the interfacial electron transport dominated Cr(VI) reduction on PBC and CBC. Moreover, the radical of •O2- had some contribution to the reduction of Cr(VI) only in the PBC system. Interestingly, •OH could promote the photoreduction of Cr(VI) in both PBC and CBC systems, which might be due to the fact that •OH facilitated the formation of small molecule fragments. These findings provide an essential basis for evaluating the environmental impact of photocatalytic behaviors of biochar.

A review on chromium health hazards and molecular mechanism of chromium bioremediation

Living beings have been devastated by environmental pollution, which has reached its peak. The disastrous pollution of the environment is in large part due to industrial wastes containing toxic pollutants. The widespread use of chromium (Cr (III)/Cr (VI)) in industries, especially tanneries, makes it one of the most dangerous environmental pollutants. Chromium pollution is widespread due to ineffective treatment methods. Bioremediation of chromium (Cr) using bacteria is very thoughtful due to its eco-friendly and cost-effective outcome. In order to counter chromium toxicity, bacteria have numerous mechanisms, such as the ability to absorb, reduce, efflux, or accumulate the metal. In this review article, we focused on chromium toxicity on human and environmental health as well as its bioremediation mechanism.

Probabilistic Risk Characterization of Heavy Metals in Peruvian Coffee: Implications of Variety, Region and Processing

Heavy metals are chemical contaminants, toxic, potentially carcinogenic and/or mutagenic, stable, persistent and are of concern in the food chain. The risk to the consumer of the presence of inorganic arsenic (iAs), cadmium (Cd), chromium (Cr), mercury (Hg) and lead (Pb) in five varieties (Bourbon, Típica, Catimor, Caturra and Pache) of parchment coffee from five regions (Amazonas, Cajamarca, Cusco, Huánuco and San Martín) was investigated in this study. A predictive model of the stages of coffee bean hulling, roasting and infusion was built to simulate the process. The results by region showed significant differences in which San Martín had the highest iAs, Cr and Pb values. The variety was only significant for Cr, of which Pache presented the highest concentration. The Cd and Hg values were below the detection limits. The hazard index (HI) was less than 1 for iAs, Cd, Cr and Hg and the combination of margin of exposure and the probability of exceedance (MOE-POE) for Pb indicated that an adverse health effect was not likely. The cancer risk (CR) for iAs and Pb in the 95th percentile was considered as both high and acceptable, respectively.

Technical guidelines for risk assessment of heavy metals in traditional Chinese medicines

BACKGROUND

Heavy metals are considered a global concern because they can deteriorate human health. This guideline aims to scientifically evaluate health risk of heavy metals in TCM and to propose a reference for decision making in developing TCM-related health policies.

METHODS

Using a multidisciplinary approach, a steering committee oversaw the development of the guideline. To obtain a reasonable and accurate risk assessment, key exposure assessment parameters for TCM, e.g., exposure frequency (EF), exposure duration (ED), and daily ingestion rate (IR) were obtained from surveys. In addition, transfer rates for heavy metals from Chinese medicinal materials (CMM) to decoctions or preparations were examined.

RESULTS

Based on the scientific theory of risk control, the guideline was designed systematically, and principles and procedures for the risk assessment of heavy metals in TCM were identified. The guideline can be utilized to assess the risk of heavy metals in CMM and Chinese patent medicines (CPM).

CONCLUSION

This guideline may help standardize the risk assessment of heavy metals in TCM, advance regulatory standards for heavy metals in TCM, and ultimately improve human health through scientific TCM usage in clinic.

Human health risk assessment of metals and metalloids in mining areas of the Northeast Andean foothills of the Ecuadorian Amazon

Gold mining (GM) is a major source of metals and metalloids in rivers, causing severe environmental pollution and increasing the exposure risks to the residents of surrounding areas. Mining in Ecuadorian Amazonia has dramatically increased in recent years, but its impacts on Indigenous local populations that make use of rivers are still unknown. The aim of this study was to assess the risks to adults and children caused by the exposure to metals and metalloids in freshwater ecosystems contaminated with tailings released by GM activities in 11 sites of the upper Napo River basin, Ecuador. We selected a carcinogenic and a noncarcinogenic risk assessment method to estimate the hazard index (HI) and total cancer risk (TCR). The concentration of Ag, Al, As, Cd, Cu, Fe, Mn, Pb, Zn, B, and V in water and sediment samples was considered to assess the risks to human health. The calculated HI was 23-352 times greater than the acceptable limits in all sites for both children and adults. Mn and Fe were the main contributors (75% in water and 99% in sediment) to the total calculated risk based on the HI. The calculated TCR for children and adults exceeded approximately one to three times the permissible threshold in all sites. As and Pb contributed up to 93% of the total calculated risk based on TCR for both children and adults. This study demonstrates that the emission and mobilization of metals and metalloids caused by mining activities increase the risk to human health, to which we recommend further monitoring of freshwater contamination in the area and the implementation of preventive health management measures. Integr Environ Assess Manag 2023;19:706-716. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Optimization and Modeling of Cr (VI) Removal from Tannery Wastewater onto Activated Carbon Prepared from Coffee Husk and Sulfuric Acid (H2SO4) as Activating Agent by Using Central Composite Design (CCD)

The primary goal of this research is to lower the hexavalent chromium (Cr (VI)) concentration that has occurred from the growth of the tannery industry. As a result, the potential for heavy metal concentration is increasing day by day. Industrial effluent containing Cr (VI) contributes significantly to water pollution. Chromium hexavalent ion (Cr (VI)) in wastewater is extremely hazardous to the environment. It is critical to address such a condition using activated carbon derived from biomass. Adsorption is one of the most successful methods for removing hexavalent chromium from wastewater. Treated wastewater has no substantial environmental contamination consequences. The ash content, moisture content, volatile matter content, and fixed carbon content of wet coffee husk were 3.51, 10.85, 68.33, and 17.31, respectively. The physicochemical properties of coffee husk-based activated carbon (CHBAC) obtained during experimentation were pH, porosity, the yield of CHBAC, bulk density, point of zero charges, and specific surface area of 5.2, 58.4 percent, 60.1 percent, 0.71 g/mL, 4.19, and 1396 m2/g, respectively, indicating that CHBAC has a higher capacity as an adsorbent medium. For optimization purposes, the parameters ranged from pH (0.3–3.7), dose (2.3–5.7) $g$ , and contact time (0.3–3.7) hr. The quadratic models were chosen for optimization, and the $p$ value for the model was significant since it was less than 0.05, but the lack of fit model was inconsequential because it was more than 0.05. The optimum adsorption obtained with numerical optimization of Cr (VI) was 97.65 percent. This was obtained at a pH of 1.926, a dose of 4.209 g/L, and a contact time of 2.101 hours. This result was observed at a pH of 1.93, a dosage of 4.2 g/L, and a contact duration of 2.1 hours. The desirability obtained during numerical optimization was 1. Coffee husk-based activated carbon has a bigger surface area, and it has a stronger ability to absorb hexavalent chromium from tannery wastewater effluents.

Health Risk Assessment of Exposure to Bisphenol A in Polymeric Baby Bottles

In recent decades, paying attention to bisphenol A (BPA), as one of the endocrine disruptor compounds, has increased due to its harmful effects. Although, scattered studies have been conducted in order to measure BPA concentration migrated into polymeric baby bottles in different countries of the world, there are no review studies and evaluation with a global perspective in the field of BPA risk. Some of these studies indicated the potential risks and estrogenic effects associated with BPA in babies' daily intake. For this purpose, we reviewed the information on the migration levels of BPA into baby bottles has been reported in 10 countries. The potential risks associated with BPA through the daily intake as well as the estrogenic effect on 3 age groups of babies which include 0 to 6, 6 to 12, and 12 to 24 months were analyzed using the Monte Carlo simulation. Also, kinetic models were applied to predict the kinetics of the migration process of BPA. The median daily intake for 3 age groups was obtained as 191.1, 161.37, and 153.76 µg/kg/day, respectively; which indicated Hazard Index (HI) > 1. The median estrogenic effect for the 3 groups was estimated to be 0.021 ngE₂/L. The kinetics of contaminant transfer with Polynomial model at 2 temperatures of 24°C and 40°C showed a better fit with R ² = 0.99 and 0.91, respectively. Based on the risk assessment analysis conducted in the present study, the BPA migration in baby bottles appeared to be a health concern for babies. Therefore, it is needed to increase the safety level of bottles for babies as they are sensitive and vulnerable members of every society. Furthermore, in this study, only the investigation of the global situation of BPA in polymeric baby bottles was stated; therefore, more investigation about another potential sources of BPA in food chain is needed.

Leaching Characteristics of Potentially Toxic Metals from Tailings at Lujiang Alum Mine, China

To investigate the leaching characteristics and potential environmental effects of potentially toxic metals (PTMs) from alum mine tailings in Lujiang, Anhui Province, soaking tests and simulated rainfall leaching experiments were conducted for two types of slag. PTMs comprising Cd, Cr, Cu, Mn, and Ni were detected in the slag. Cu and Cd contents exceeded the national soil risk screening values (GB 15618-2018). pH values of the two slag soaking solutions were negatively correlated with the solid:liquid ratio. pH values of the sintered slag soaking solutions with different solid:liquid ratios finally stabilized between 4.4 and 4.59, and those of the waste slag soaking solutions finally stabilized between 2.7 and 3.4. The concentrations of Cd, Cr, Cu, Mn, and Ni leached from waste slag were higher than those from sintered slag, and the dissolved concentrations of these PTMs in sintered slag were higher under rainfall leaching conditions than soaking conditions (the difference in Cr concentration was the smallest, 5.6%). The cumulative release of Cd, Cr, Cu, Mn, and Ni increased as the leaching liquid volume increased. The kinetic characteristics of the cumulative release of the five PTMs were best fitted by a double constant equation (R² > 0.98 for all fits). Single factor index evaluations showed that Mn and Ni were the PTMs with high pollution degrees (P_i for Mn and Ni exceed 1) in the leaching solutions. However, considering the biotoxicity of PTMs, the water quality index evaluations showed that the water quality of the sintered slag soaking solution, the waste slag soaking solution, and the sintered slag leachate was good, poor, and undrinkable, respectively. The health risk assessment showed that the total non-carcinogenic risk (HI) values in adults for both the sintered slag leachate and waste slag soaking solution exceeded the safe level of 1, with HI values of 3.965 and 2.342, respectively. The hazard quotient (HQ) for Cd was 1.994 for the sintered slag leachate, and Cd and Cr make up 50.29% and 15.93% of the total risk, respectively. Cr makes up 28.38% of the total risk for the waste slag soaking solution. These results indicate a high non-carcinogenic risk of exposure to Cd and Cr in the leaching solution used for drinking purposes. These findings may provide a reference for the evaluation and ecological control of PTM pollution in alum mining areas.

Polycyclic aromatic hydrocarbons (PAHs) in soils around oil refineries; Case study: Erbil and Kirkuk refineries, Iraq- A modelling approach

Purpose

Political tensions in Iraq have made attention to environmental issues not a priority for the authorities. Therefore, the influence of Kirkuk and Erbil refineries on contamination of the surrounding soil by polycyclic aromatic hydrocarbons (PAHs), were studied.

Methods

25 soil samples were collected and analyzed using high-performance liquid chromatography (HPLC), and their fate and health risk were investigated using Exposure Model for Soil-Organic Fate and Transport (EMSOFT) and the Monte Carlo Simulation (MCS) model.

Results

High ∑PAHs contamination (raged from 212.8 to 12,790.4 ppb), the dominance of pyrogenic sources, and high ecological risk were observed. The mean hazard index values for children (0.043) are higher than those for adults (0.02), while the incremental lifetime carcinogenic risk values for adults (8.50E-4) are greater than those for children (5.27E-4). Pyrene is the significant soil PAH from the depth of 3 cm downwards, while phenanthrene and fluorene are the major constituents of PAHs between the depth of 3 and 10 cm. Also, low molecular weight PAHs significantly decrease in soil layers over the time frame, and maximum PAHs concentrations belong to high molecular weight PAHs over 20 years.

Conclusion

Using an appropriate monitoring system, as well as sound management decisions to reduce the emission of environmental pollution are needed. Also, it seems that the use of constant values for soil physicochemical parameters such as moisture and porosity, despite seasonal variations, may result in uncertainty for fate and transport modelling. Therefore, seasonal sampling and analysis of soil parameters, would be helpful.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40201-022-00809-y.

Health Risk Assessment during In Situ Remediation of Cr(VI)-Contaminated Groundwater by Permeable Reactive Barriers: A Field-Scale Study

The presence of residual Cr(VI) in soils causes groundwater contamination in aquifers, affecting the health of exposed populations. Initially, permeable reactive barriers(PRB) effectively removed Cr(VI) from groundwater. However, as PRB clogging increased and Cr(VI) was released from upstream soils, the contamination plume continued to spread downstream. By 2020, the level of contamination in the downstream was nearly identical to that in the upstream. The study results show that during normal operation, the PRB can successfully remove Cr(VI) from contaminated groundwater and reduce the carcinogenic and non-carcinogenic risks to humans from the downstream side of groundwater. However, the remediated groundwater still poses an unacceptable risk to human health. The sensitivity analysis revealed that the concentration of the pollutant was the most sensitive parameter and interacted significantly with other factors. Ultimately, it was determined that the residual Cr(VI) in the soil of the study region continues to contaminate the groundwater and constitutes a serious health danger to residents in the vicinity. As remediated groundwater still poses a severe threat to human health, PRB may not be as effective as people believe.

Estimating adults and children's potential health risks to heavy metals in water through ingestion and dermal contact in a rural area, Northern Tunisia

High concentrations of heavy metals (HMs) in water (e.g., As, Cr, and Cd) are harmful to human health, especially to children. HMs' (As, Cd, Mn, Fe, Cu, Hg, Zn, Cr, and Se) values have been determined from the water of the Guenniche plain (Tunisia); then the carcinogenic risk (CR) and non-carcinogenic Risk (N-CR) were estimated through ingestion and dermal contact for adults and children. The analysis results show that the Hg, As, and Cd in 50% of the ephemeral streams (ESs) exceeded one of the WHO and NT guidelines for safe water, as is the case with Hg and Cd in 25% of the shallow groundwater wells (SGW). In all samples, the N-CR of all HMs, and the CR due to the dermal contact controlled by As, for both age brackets, are deemed to fall far short of the threshold set by USEPA. The CR due to the ingestion pathway caused by As, Cr, and Cd contamination indicates a "high" to "very high" risk on its users in roughly 50% of all the samples (ESs and SGW) for both age brackets by exceeding 10^-5. Overall, the SGW samples close to the floodplain area of the ESs pose a real CR to both age groups, which is more serious for children. Therefore, the SGW are not recommended for drinking use, with an urgent call for a solution by the policy-makers to improve the water quality of the region.

Health risk assessment of commercial fish and shrimp from the North Persian Gulf

BACKGROUND

Bioaccumulation of trace metals in the food web demands continuous monitoring of seafood safety. Here, the food safety of commercial fish bluespot mullet Crenimugil seheli, deep flounder Pseudorhombus elevates, and Jinga shrimp Metapenaeus affinis was assessed from commercial and industrial region of the West Bandar Abbas, the North Persian Gulf, for the first time.

METHODS

For this purpose, concentrations of trace metals Ni, Zn, Cu, Cr, Cd, and Pb, and their health risks were investigated.

RESULTS

Results showed the average concentration of all trace metals in all species was below concentrations proposed by WHO/FAO/USEPA. The finding on risk assessment of three species indicated three species are safe for daily consumption. Long-term consumption of three species would not pose potential non-carcinogenic health risk. However, it would result in carcinogenic effects from the ingestion of trace metals Ni, Cr, and Cd.

CONCLUSIONS

The data emphasizes the need for the continuous monitoring in this industrial region in the future to manage and control pollutant sources and to ensure the quality of seafood.

Management and health risk assessment of chemical contamination events in water distribution systems using PSO

An accidental or intentional contamination event can raise health and sociopolitical concerns, erode public trust, and affect the operation of water distribution systems. In this regard, emergency management plans are required to describe the necessary measures in order to deal with a threat. This study was carried out to investigate the best ways to manage intrusion in a water distribution network. In this research, the optimal management approach to deal with chemical contamination in a water distribution network was examined under three scenarios using the particle swarm optimization method. In each scenario, three management solutions were used to manage the contamination, including closing the pipe, opening the fire hydrant, and using a combination of pipe closure and fire hydrant opening. Contamination risk impact on consumers' health was assessed in the network's emergency status and after implementation of the best pollution management scenarios. The results showed that in the benchmark network, pipe closure was slightly more successful than opening of the fire hydrant valve. In pollution management of a real network, pipe closure was less effective than the hydrant opening in all scenarios. Generally, all applied scenarios were successful in reducing the contamination risk among the exposed people, so that carcinogenic and non-carcinogenic risks reduced by 100% in all scenarios compared to the non-management state.

Carcinogenic Risk Assessment among Children and Adult due to Exposure to Toxic Air Pollutants

Health endpoint and risk of carcinogenic among people enhancement due to Exposures to toxic air pollutants. The purpose of this study was investigation of a carcinogenic risk assessment among children and adults due to exposure to toxic pollutants. A review study of literature was performed with seven hundred and twenty-six articles were retrieved based on Google Scholar, Web of Science, PubMed, Elsevier, and Springer databases. Studies reporting data on predetermined consequences potential toxic air pollutants and related to lifetime cancer risk (LCR) and hazard quotient (HQ) were used to assess carcinogenic and non-carcinogenic risk. The literature signs a notable undesirable affect from potential toxic air pollutants related to carcinogenic risk assessment among children and adult. Based on Result this study, the toxic air pollutants can endanger health of children and adult exposure to this pollutant and increase lifetime cancer risk number and carcinogenic risk among exposed people. Useful for health policymaker in order to cope with the incidence of cancer among citizenship Can be the main application the results of this study. Increasing the level of public awareness, especially of sensitive groups, about the incidence of cancer and its important factors and reduce exposures to toxic air pollutants are the main vital government actions for decrease the prevalence of cancer. Further research using more sophisticated methodology is warranted.

Characterization of drinking groundwater quality in rural areas of Inner Mongolia and assessment of human health risks

Groundwater is an important natural resource of drinking water in rural areas in Inner Mongolia, China. In this study, 4438 drinking groundwater samples were collected from the rural areas of 81 counties in Inner Mongolia, and were analyzed for 16 parameters, including pH, total hardness (TH), chemical oxygen demand (COD), total dissolved solids (TDS), sulfate (SO42-), chloride (Cl-), fluoride (F-), iron (Fe), manganese (Mn), arsenic (As), cadmium (Cd), hexavalent chromium (Cr), lead (Pb), aluminum (Al), cuprum (Cu), zinc (Zn). The groundwater quality was evaluated with water quality index (WQI) and human health risk assessment (HRA). Monte Carlo simulation were applied for the uncertainty and sensitivity analysis in the health risk assessment. The spatial map was employed based on the inverse distance weighted (IDW) interpolation technique. The results reveal that while the hazard quotient (HQ) suggests that the risk of single element contamination is feeble, the hazard index (HI) indicates a potential health risk for the local population. The observed cumulative carcinogenic risk (CCR) indicates a probable risks of carcinogenic health hazards in the study area. The sensitivity analysis revealed that daily ingestion rate (IR), exposure frequency (EF), and the concentrations of As, Mn, F-, and Cr are the most influential parameters for health hazards. The highly polluted areas are mainly distributed in the central and western regions of Inner Mongolia, including Xianghuangqi, New Barag Zuoqi, and Togtoh. It is observed that the groundwater may cause a potential health risk after long-term ingestion. The results of this study will contribute to groundwater management and protection in Inner Mongolia.

Non-carcinogenic risk assessment of exposure to heavy metals in underground water resources in Saraven, Iran: Spatial distribution, monte-carlo simulation, sensitive analysis

Groundwater aquifers are considered the second most abundant water supply for drinking water all over the world. In Iran, ground waters are commonly employed for drinking water, irrigation, and industrial purposes. Heavy metals (HMs) pose human concerns about the groundwater contamination; these pollutants are recognized to be capable of bio-accumulation, long persistence in the natural environment, and toxic effects. In the present research, the content of HMs: Chromium (Cr), Cadmium (Cd), and Lead (Pb) were detected in 89 water samples collected in 2018 by underground water supplies (active wells) of Saravan city. Hazard Quotient (HQ) and Monte Carlo Simulation approach with 10,000 repetitions were applied to discover the human non-carcinogenic impacts of HMs in four groups of ages (adults, teenagers, children, and infants) of consumers. The concentrations of Cr, Pb, and Cd were in the range of 0.49-20, 0.1 to 58.34, and 0.11-12.8 μg/L, respectively. The mean HQ calculated due to exposure to Pb (0.0018-0.0023), Cr (0.0112-0.0186), and Cd (0.0370-0.0615) were lower than one. The findings of sensitivity analysis revealed that HMs concentration had the most contribution effect on human non-carcinogenic risk analysis in four different exposed populations. This study could assist researchers to perform more comprehensive studies with more samples. Therefore, further research is required for decision-makers to plan proper measurements properly.

Health risk assessment of total chromium in the qanat as historical drinking water supplying system

This study investigated the health risk assessment of total chromium (Cr_T) in qanats of South Khorasan, Eastern Iran. For this, concentration of Cr_T in a total of 83 qanats were measured in summer 2020. Samples were initially tested in the field for temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), and total dissolved solids (TDS). In the lab, collected samples were filtered and fixed with nitric acid (HNO₃) for the detection of Cr_T using inductively coupled plasma mass spectrometry (ICP-MS). Hazard quotient (HQ) and carcinogenic risk assessments were considered to evaluate the risks of Cr_T to inhabitants. Results showed that concentration of Cr_T ranged from 1.79 to 1017.05 μg L^-1, and a total of 25 stations illuminated Cr_T concentrations above the WHO standards (50 μg L^-1). HQ demonstrated HQ < 1 for 90.37% of studied samples with negligible hazard, whereas 9.63% of stations illuminated HQ ≥ 1 meaning the presence of non-carcinogenic risk for water consumers. Carcinogenic risk (CR) exhibited CR > 1.00E-04 in 81.93% of qanats while 18.07% of stations had 1.00E-06 < CR < 1.00E-04 meaning no acceptable and acceptable CR for the studied qanats, respectively. Zoning map displayed that qanats in the south of South Khorasan possessed the highest HQ, but north regions showed the lowest ones. Together, Cr_T in qanats of South Khorasan is above the WHO limit, which results in a high risk of carcinogenicity for residents, and in turn, more efforts should be made to provide hygienic groundwater for consumers.

Probabilistic multi-pathway human health risk assessment due to heavy metal(loid)s in a traditional gold mining area in Ecuador

Mining operations are important causes of environmental pollution in developing countries where mining waste management is not adequate. Consequently, heavy metal(loid)s are easily released into the environment, being a potential risk to human health. This study carries out a Bayesian probabilistic human health risk assessment, related to multi-pathway exposure to heavy metal(loid)s in a gold mining area in Southern Ecuador. Concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn in tap water, surface water, and soil samples, were analyzed to assess the potential adverse human health effects based on the Hazard Index (HI) and Total cancer risk (TCR). Adults and children residents were surveyed to adjust their exposure parameters to the site-specific conditions. Exposure to heavy metal(loid)s resulted in unacceptable risk levels for human health in the two age groups, both carcinogenic (TCR > 1 × 10-5) and non-carcinogenic (HI > 1) through ingestion of tap water and incidental ingestion of surface water. Sensitivity analysis showed that As concentration in waters and exposure frequency were the main contributors to risk outcome. Exposure to soil via accidental ingestion and dermal contact was below the safety limit, not posing a risk to human health. These findings can provide a baseline for the environmental management of the mining area and indicate the need for further research on As pollution in water and its implications on the health of the inhabitants of mining communities.

Health risk assessment of occupational exposure to heavy metals in a steel casting unit of a steelmaking plant using Monte-Carlo simulation technique

The present work aimed to evaluate the health risks of occupational exposure to heavy metals in a steel casting unit of a steel plant. To determine occupational exposure to heavy metals, personal air samples were taken from the workers' breathing zones using the National Institute for Occupational Safety and Health method. Noncancer and cancer risks due to the measured metals were calculated according to the United States Environmental Protection Agency procedures. The results indicated that the noncancer risks owing to occupational exposure to lead (Pb) and manganese were higher than the recommended value in most of the workstations. The estimated cancer risk of Pb was also higher than the allowable value. Moreover, the results of sensitivity analysis indicated that the concentration, inhalation rate, and exposure duration were the most influencing variables contributing to the calculated risks. It was thus concluded that the present control measures were not adequate and further improvements were required for reducing the exposure levels.

Presence of heavy metals in drinking water resources of Iran: a systematic review and meta-analysis

Water quality is one of the most important indices for public health especially for drinking water consumptions. This study was conducted to survey the presence of heavy metals in drinking water resources of Iran using a systematic review and meta-analysis. The literature search was conducted in data bases of PubMed, Web of Science, EMBASE, Scopus, Google Scholar, and some Persian databases up to 31 July 2018. Of all the articles reviewed (1151 articles), 61 papers were eligible for systematic review. Results indicated variable heterogeneity between studies for different pollutants (I² between 0 and 100). A subgroup analysis was performed for three different types of water resources such as drinking water, groundwater, and surface water to find the possible source of the heterogeneity. The pooled mean concentration level of iron was the highest at 255.8 (95% CI = 79.48-432.13 μg/l) and vanadium the lowest at 3.21 (95% CI = 1.45-4.98 μg/l). The sequence of metal concentration (μg/l) in descending order is as follows: Fe (255.8) > B (159.81) > Al (158.5) > Zn (130.73) > As (85.85) > Mn (51.61) > Cu (47.98) > Se (42.68) > Pb (37.22) > Co (22.76) > Mo (18.92) > Ni (16.79) > Cr (13.47) > Hg (4.49) > Cd (4.19) > V (3.21). The mean pooled concentration level of Al, As, Se, Pb, and Cd was higher than the WHO guideline and Iran Standard, and the rest of the metals had lower mean pooled concentration level. Pb and Cd were the common heavy metals that existed in all subgroups. As a recommendation, the relationship assessment of water parameters and heavy metals could be addressed in future studies of Iran's water resources.

Chromium pollution and its bioremediation mechanisms in bacteria: A review

Environment pollution is at its peak and is creating havoc for living beings. Industrial wastes containing toxic pollutants have contributed to a great extent in this disastrous environment pollution. Chromium (Cr³⁺/Cr⁶⁺) is highly toxic and one of the most common environmental pollutants because of its extensive use in industries especially tanneries. Lack of efficient treatment methods has resulted in extensive chromium pollution. Bioremediation of chromium using bacteria is very thoughtful due to its eco-friendly and cost-effective outcome. Bacteria possess numerous mechanisms such as biosorption, reduction, efflux or bioaccumulation, naturally or acquired to counter the toxicity of chromium. This review focuses on the bacterial responses against chromium toxicity and scope for their application in bioremediation. The differences and similarities between Gram negative and positive bacteria against chromium are also highlighted. Further, the knowledge gap and future prospects are also discussed in order to fill these gaps and overcome the problem associated with real-time applicability of bacterial bioremediation.

Exposure Assessment of Multiple Mycotoxins and Cumulative Health Risk Assessment: A Biomonitoring-Based Study in the Yangtze River Delta, China

The extensive exposure to multiple mycotoxins has been demonstrated in many countries; however, realistic assessments of the risks related to cumulative exposure are limited. This biomonitoring study was conducted to investigate exposure to 23 mycotoxins/metabolites and their determinants in 227 adults (aged 20-88 years) in the Yangtze River Delta, China. Eight mycotoxins were detected in 110 urine samples, and multiple mycotoxins co-occurred in 51/227 (22.47%) of urine samples, with deoxynivalenol (DON), fumonisin B1 (FB1), and zearalenone (ZEN) being the most frequently occurring. For single mycotoxin risk assessment, FB1, ZEN, aflatoxin B1 (AFB1), and ochratoxin A (OTA) all showed potential adverse effects. However, for the 12 samples containing DON and ZEN, in which none had a hazard risk, the combination of both mycotoxins in two samples was considered to pose potential endocrine disrupting risks to humans by hazard index (HI) method. The combined margin of exposure (MOET) for AFB1 and FB1 could constitute a potential health concern, and AFB1 was the main contributor. Our approach provides a blueprint for evaluating the cumulative risks related to different types of mycotoxins and opens a new horizon for the accurate interpretation of epidemiological health outcomes related to multi-mycotoxin exposure.

Probabilistic health risk assessment of occupational exposure to isoflurane and sevoflurane in the operating room

Risk assessment is an important tool in predicting the possible risk to health. It heightens awareness by estimating the probability of adverse health effects in humans who are exposed to chemicals in the course of their work. Therefore, the present work aims to determine the occupational exposure of operating room staff to the volatile anesthetic gases, isoflurane and sevoflurane, and estimates non-cancer risk using the United States Environmental Protection Agency method. Air samples from the breathing zone of staff members were collected using the Occupational Safety and Health Administration Method 103 and analyzed using gas chromatography-mass spectroscopy. The results indicate that the measured concentrations of isoflurane and sevoflurane are below the National Institute of Occupational Safety and Health standard (2 ppm) for technicians and nurses, but not for anesthesiologists and surgeons. Moreover, the estimated non-cancer risk due to isoflurane is above the acceptable value for anesthesiologists (but acceptable for other occupational categories). A sensitivity analysis indicates that exposure time has the most effect on calculated risk (53.4%). Occupational exposure to anesthetic gases may endanger the health of operating room personnel. Therefore, control measures, such as daily testing of anesthetic devices, ensuring the effectiveness of ventilation systems, advanced scavenging methods, and regular training of staff are highly recommended.

Health risk assessment of potentially toxic elements intake via food crops consumption: Monte Carlo simulation-based probabilistic and heavy metal pollution index

The aim of this study is to assess the content of heavy metals and their potential health risk in consumed food crops. To this end, the samples from vegetables, rice, potato, onion, and black tea were derived from high sales and commonly consumed types. The noncarcinogenic health risk of heavy metals to the adults, teens, and children was estimated by target hazard quotients (THQs) and hazard index (HI) calculation. Sensitivity and uncertainty analyses were carried out using Monte Carlo simulations. Heavy metal pollution index (HMI) was used for ranking noncarcinogenic heavy metal pollution in sampled food crops. THQs showed that noncarcinogenic health risks to the local population were largely related to As (0.71 for adults, 0.87 for teens, and 2.4 for children), Mn (0.43 for adults, 0.28 for teens, and 0.64 for children), and Mo (0.12 for adults, 0.02 for teens, and 0.4 for children). HI for individual food crops (HI_Σfi) in terms of different populations showed that the highest HI_Σfi was for children while the highest HI_ΣTea was for adults. The arrangement of the calculated HI_Σfi along with its highest value was in the order of HI_ΣRice (3.71) > HI_ΣTea (0.39) > HI_ΣBeans (0.2) > HI_ΣVegetables (0.13) > HI_ΣOnion (0.12) > HI_ΣPotato (0.11). The value of HI for all sampled food crops based on their daily ingestion rate achieved by deterministic and probabilistic (Monte Carlo simulations) approaches for adults, teens, and children was 1.63, 1.28, and 1.87, 1.67, 4.51, and 2.48 respectively, and revealed that all populations are vulnerable to the significant noncarcinogenic health risks and children are at more risk. The sensitivity analysis revealed that the ingestion rate (IR) is the most influential factor that contributed to the total risk. The determined HMI showed no heavy metal pollution for all food crops, and rice had higher-order in HMI ranking. These results showed that heavy metals exposure due to food ingestion is a threat to human health and needs choosing a proper strategy to reduce heavy metal exposure.

Health risk assessment of Cd, Cr, Cu, Ni and Pb in the muscle, liver and gizzard of hen's marketed in East of Iran

The present study aimed to determine the average concentration of some metals, including cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and lead (Pb) in the chicken, hen's liver, and gizzard in the east of Iran. Estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and carcinogenic risk (CR) were calculated. In this cross-sectional study, fifty one samples including chicken, hen's liver and gizzard were obtained from Birjand, Iran. Measurement of Cd, Cr, Cu, Ni, and Pb was carried out by using an Inductively Coupled Plasma-Optic Emission Spectroscopy (ICP-OES). All of the measured metals were detected in 100 % of the samples. The metals had a different distribution pattern. The highest concentration of Cd and Cu was in the liver samples while the Cr and Ni had the highest levels in the chicken. Pb concentration was at the highest level in the gizzard. The least amount of Cr, Ni, and Pb was found in the liver while Cu had the least content in the muscle. EDI had an acceptable level, but the highest daily intake of all studied metals was through muscle. Cr had the highest THQ and it was more than one in the meat. HI in chicken was more than one. Liver and gizzard of hens had a neglectable HI. CR was neglectable in the case of both Cd and Pb, but it was considerable for Cr and Ni. The consumption of chicken in both adults and children may pose a significant health risk for consumers.

Polycyclic aromatic hydrocarbons in railway stations dust of the mega traffic hub city, central China: Human health risk and relationship with black carbon

Twenty dust samples collected from Wuchang and Wuhan Railway Stations, the biggest transport stations in the mega traffic hub city in Central China, were analyzed for polycyclic aromatic hydrocarbons (PAHs) to investigate the concentration, sources apportionment, and relationship with black carbon (BC) and assess the health risk. The results suggested that the concentrations of PAHs, BC and TOC in Wuhan Railway Station (WHRS) (PAHs = 5940 ± 1920 ng g^-1, BC = 53.2 ± 23.1 mg g^-1 and TOC = 80.7 ± 44.4) were twice higher than those in Wuchang Railway Station (WCRS) (PAHs = 2580 ± 1630 ng g^-1, BC = 20.4 ± 14.3 mg g^-1 and TOC = 33.9 ± 20.1 mg g^-1). Moreover, the 3 - and 4 - rings PAHs were major PAHs in railway station dust. The composition pattern of PAHs in these railway station dusts had a common characteristic with HMW-PAHs contribution. The results of source identification revealed that different local development features and energy consumption of trains would influence the sources of PAHs and BC. PAHs and BC were most likely related to industrial activities in WHRS. Coal and biomass combustion may influence the PAHs components and BC distribution in WCRS. Moreover, BC had played an important role in retaining PAHs in urban railway stations. Especially in WHRS, BC would more likely to absorb the high molecular weight PAHs, such as 4 -ring (p<0.05), 5 -ring (p<0.05) and 6 -ring (p<0.05) PAHs; while BC just played limited roles in the binding of volatile and semi-volatile organic pollutants, such as 2 -ring and 3 -ring PAHs. With the coexistence of BC and PAHs, passengers would face significant potential health risks by exposure to toxic dust in railway stations, especially for children. The cancer risk in WHRS was almost twice higher than that in WCRS, and it would tend to be stable by a semi-confined structure in the platform area.

Health risk assessment of heavy metals and strontium in groundwater used for drinking and cooking in 58 villages of Prakasam district, Andhra Pradesh, India

Groundwater is one of the most important sources of water for drinking and cooking in rural India. A total of 382 groundwater samples were collected from 58 villages and analyzed for HMs and Sr by inductively coupled plasma mass spectrometer. The average concentrations of HMs and Sr in water was in the order of strontium (Sr) > arsenic (As) > chromium (Cr) > lead (Pb) > mercury (Hg) > cadmium (Cd). Out of 58 villages, 21, 37, 35, 35, 35 and 39 villages had Cr, As, Cd, Hg, Pb and Sr higher (WHO limit) than their respectively permissible levels. Health risk assessment of HMs and Sr for humans revealed that the non-carcinogenicity hazard quotients (HQ_i+d) for HMs and Sr were higher than unity for adult and children. The hazard index (HI) was 531.066 for adult and 902.926 for children. The HI > 1 was observed in 45 villages for adults and 56 villages for children. The lifetime cancer risk in adult for As_i, As_d, and Pb_i in 36, 25 and 23 villages, whereas in children was 42, 20 and 22 villages, respectively. In conclusion, the health risks arising from consumption of groundwater containing HMs and Sr indicated that there is a significant carcinogenic risks for adult and children. This is the first attempt to provide information on the health risks of Sr in drinking water in India. The present findings can be useful for the development of potential strategies for risk control and management.

Probabilistic human health risk assessment associated with fluoride and arsenic co-occurrence in drinking water from the metropolitan area of San Luis Potosí, Mexico

A major public health concern in Mexico is the natural contamination of groundwater with fluoride and arsenic. Therefore, this work aimed to evaluate the magnitude of human health risk after determining fluoride and arsenic concentrations in groundwater samples (n = 50) from the Metropolitan area of the city of San Luis Potosi, Mexico. Fluoride levels in water were determined via a potentiometric method using an ion-selective electrode. Arsenic concentrations in water samples were determined with an Atomic Absorption technique. Subsequently, a probabilistic health risk assessment was developed (Monte Carlo Analysis). Fluoride levels in water ranged from 0.20 to 3.50 mg/L. For arsenic, the mean level found in the assessed water samples was 15.5 ± 5.50 μg/L (range: 2.50-30.0 μg/L). In addition, when the probabilistic health risk assessment was completed, a mean HI (cumulative hazardous index) of higher than 1 was detected, indicating a high NCR (non-carcinogenic risk) for children and adults. According to the results found in this study, exposure protection campaigns are imperative in the Metropolitan area of the city of San Luis Potosí, Mexico, to successfully diminish exposure to arsenic and fluoride and, as a consequence, decrease the NCR in the population living in that region of Mexico.

Preparing the optimal emergency response protocols by MOPSO for a real-world water distribution network

Water security is considered as one of the critical subjects that can arise from different issues, for instance, the injection of a poisonous pollutant into the drinking water system of a city followed by a terrorist attack. If the network lacks optimal operation to provide security against this threat, the whole population of the city can be affected by such an incident. This study aimed at preparing the optimal emergency response protocols by multi-objective particle swarm optimization (MOPSO). Furthermore, it calculates the risk of contaminants entering the network. The problem consists of three main objectives: 1) minimizing the number of operational interventions, 2) minimizing the number of polluted nodes, and 3) minimizing the number of exposed individuals. The location of closed valves and opened hydrants was chosen as decision variables. The proposed method is demonstrated using a benchmark and a real network.

Recent advances in the application of metabolomics for food safety control and food quality analyses

As one of the omics fields, metabolomics has unique advantages in facilitating the understanding of physiological and pathological activities in biology, physiology, pathology, and food science. In this review, based on developments in analytical chemistry tools, cheminformatics, and bioinformatics methods, we highlight the current applications of metabolomics in food safety, food authenticity and quality, and food traceability. Additionally, the combined use of metabolomics with other omics techniques for "foodomics" is comprehensively described. Finally, the latest developments and advances, practical challenges and limitations, and requirements related to the application of metabolomics are critically discussed, providing new insight into the application of metabolomics in food analysis.

Comparing THMs level in old and new water distribution systems; seasonal variation and probabilistic risk assessment

Trihalomethanes (THMs) in drinking water are associated with many chemical parameters in water. However, the available evidence on the relationship between physical parameters of the water distribution system (WDS) and THMs is still scarce; therefore, this study aimed to compare the THMs concentration in the old and new WDS in Yazd, Iran. Moreover, we investigated the seasonal trend and health risk assessment of exposure to THMs through ingestion, dermal, and inhalation pathways. Mann-Whitney test was applied to compare THMs between old and new WDS as well as fall season and winter season. The order of THM concentrations was: chloroform > BDCM > DBCM > bromoform. The maximum levels of THMs in the fall and winter were 31 and 39 ppb, respectively, which were less than the WHO recommended limits for drinking water, i.e., <200 ppb. There was a significant difference between the concentration of BDCM in autumn and winter (P-value = 0.01). There was a marginally significant difference between THM concentration in the autumn and winter (P-value 0.09). The total concentration of THMs and chloroform in the old WDS were significantly higher than the new WDS. The mean values of lifetime cancer risks (LTCR) for oral, dermal, and inhalation exposure pathways to THMs were in the acceptable and low-risk levels. The inhalation exposure pathway had the highest LTCR from among the three mentioned exposure pathways. The hazard index was found to be < 1 through oral and dermal pathways. Moreover, the sensitivity analysis revealed that the ingestion rate for oral exposure, the exposure time for dermal and exposure duration for the inhalation exposure pathway had the highest impact on chronic daily intake (CDI). Our finding confirmed that THM concentration in tap water was associated with the lifespan of WDS and this finding could be useful for urban planners and decision-makers.

Risk assessment of trace elements pollution of Manaus urban rivers

Manaus is the Capital City of Amazonas State, Brazil, in the heart of the Amazon rainforest. Its metropolitan area has a huge hydrographic basin where the disorganized urbanization has caused adverse effects in the urban rivers and creeks water quality. Thus, this study was conducted to evaluate the contents of Ba, Cr, Mn, Zn, Ni, Cu, the physicochemical parameters and their respective health risks in water samples from rivers and creeks located in urban areas with different degrees of urbanization in two different seasons. The determination of the physicochemical parameters showed the samples collected in areas with riparian vegetation presented mean values of temperature, pH, total dissolved solids and electrical conductivity lower than samples collected in urban environment. The hotspots of trace elements content were associated to the presence of industrial and domestic effluents as the main pollution source. The Water Quality Index results denoted a low water quality in four sampling sites, one during the rainy season and three others during the dry season. The overall non-carcinogenic health in the urban rivers was considered high in regions with huge population and intense anthropogenic activity. The results showed the potential risk of some of the trace elements on human beings, especially on children. The main element contributor to non-carcinogenic risk was Cr, although Mn and Ni also contributed to non-carcinogenic risk in a few areas, mainly for children during the dry season.

Cadmium and chromium levels in water and edible herbs in a risk assessment study of rural residents living in Eastern Iran

In arid and semi-arid regions of Iran, water is supplied by qanats, underground channels where pollution is suspected, but unestablished. The aim of this study was thus to run a risk assessment study regarding the levels of cadmium (Cd) and chromium (Cr) in qanat water and edible herbs (Adiantum capillus-verenis, Chara globularis and Plantago lanceolata) growing in qanats in 14 villages in South Khorasan Province in Iran between April and August 2018. Samples were collected in qanats from the same sampling points, and after mineralization in nitric and perchloric acids were analyzed for metal concentrations by means of atomic absorption spectrometry. Concentrations of Cd and Cr found in water were not high (0.028 and 1.091 μg L^-1, respectively) and contamination parameters revealed no pollution. The ingestion rate of water and the exposure frequency to metals were the most relevant variables in the model of a sensitivity analysis, but the Hazard Quotient indicated no risk of non-carcinogenic health problems to consumers of the water. The Carcinogenic Risk parameter suggested, however, that there is a risk of these consumers' developing cancer. Concentrations found in herbs were higher than in water but remained below permissible thresholds. Hazard Quotient values of three species studied in the case of children and A. capillus-verenis in the case of adults indicated a potential non-carcinogenic health risk linked with eating them. The study reveals that further research to include many of the qanats across Iran should be carried out to verify the scale of the risk suggested. Graphical abstract.

Immobilization of Cr(VI) on engineered silicate nanoparticles: Microscopic mechanisms and site energy distribution

Engineered nanoparticles-mediated contaminant transport has been recognized as a significant process governing the mobility of metals and radionuclides in groundwater. Engineered silicate nanoparticles (ESNPs) are attractive materials for the sequestration or extraction of Cr(VI) and other metals and radionuclides from groundwater. While great efforts have been devoted toward the application of these materials for Cr(VI) sequestration, the underlying interface adsorption mechanism is not thoroughly elucidated. This study investigates the immobilization mechanisms of Cr(VI) on a representative ESNPs, NH₂-MCM-41, over a range of water chemistry conditions. By combining batch adsorption experiments with an array of complementary characterizations, we provided spectroscopic and microscopic evidence that the electrostatic interactions between the positively charged NH₂-MCM-41 surface derived from amino functionality and the negatively charged Cr(VI) species was the dominant mechanism responsible for Cr(VI) immobilization. In addition, the weak hydrogen bonding interactions may also contribute to adsorption to a degree. Furthermore, thermodynamic studies suggested a favorable, spontaneous, and exothermic adsorption process. Site energy analysis illustrated that the distribution of energy binding sites on NH₂-MCM-41 is Cr(VI) loading dependent. The new insights provided here can advance understanding of the transport of Cr(VI) associated NH₂-MCM-41 that benefits the application of ESNPs-based technologies for metals immobilization in groundwater.

Environmental and human health risks from metal exposures nearby a Pb-Zn-Ag mine, China

Metal contamination in mining areas, where mining and farming coexist, is of great concern worldwide. Nevertheless, a disconnection exists between those risks to environmental and human health. In this study, an integrated approach was used to connect the environmental and human health risks from metal exposures nearby a Pb-Zn-Ag mine. The field survey showed metal contamination in soils and crop plants as well as variation in soil microbial community in mining region relative to the reference site. Together with non-carcinogenic and carcinogenic risk assessment with a probabilistic approach, Cd and Cr were identified as the priority contaminants. Further, consumption of contaminated food crops was a significant pathway of human exposure. Especially, children were susceptible to metal contamination with non-carcinogenic hazard index (0.45 for soil ingestion and 1.19 for dietary intake) and carcinogenic risk index (3.47 × 10^-4 for soil ingestion and 5.10 × 10^-3 for dietary intake) at the 50th percentile. These findings facilitate the priority actions on mitigation strategies to minimize the environmental and health risks. Also, the potential environmental and human health consequences due to uncontrolled mining in this region serve as a case study for other regions involved in mining activities.

Thyroid dysfunction: how concentration of toxic and essential elements contribute to risk of hypothyroidism, hyperthyroidism, and thyroid cancer

This study was conducted to evaluate the levels of trace metals Fe, Cr, Co, Cd, Cu, Ni, Hg, Zn, and Pb in healthy individuals and patients with thyroid disease (hyperthyroidism, hypothyroidism, and cancerous). The serum levels of 110 participants living in Birjand City, east of Iran, were collected and analyzed using ICP-MS (Agilent 7900). Results showed that the concentration levels of Cr, Co, Zn, Cd, and Pb were significantly higher at case-patients (p < 0.05), but the levels of Fe, Ni, and Hg were similar between healthy and patient subjects (p > 0.05). In patients with high or low thyroid activity, strong mutual correlations between Cr, Ni, and Fe were noticeable (p < 0.05). In hypothyroid patients, no significant correlation between Zn and Hg, Co, and Cd was found, but Zn was moderately and positively correlated with other trace metals. The moderate negative correlations between Cd-Cr (p = - 0.46) and Cd-Fe (p = - 0.43) were also observed. Logistic regression analysis showed that the effect of Cr, Co, Pb, Cu, Zn, and Cd was significant in developing hyperthyroidism and hypothyroidism; whereas, in patients with thyroid cancer, the effect of Cr, Cd, and Pb was found to be significant. In conclusion, our findings suggest that toxic metals such as Pb, Cd, and Cr can increase the risk of developing hypothyroidism and thyroid cancer, but more research is needed to evaluate the potential toxicity mechanisms of Pb, Cd, and Cr.

Assessment of the possibility of using deciduous tree bark as a biomonitor of heavy metal pollution of atmospheric aerosol

The aim of the research was to assess the possibility to use deciduous tree bark in the biomonitoring of urban areas. The tree bark taken from various deciduous tree species growing in the Opole Province (south-western Poland) was used for the research. The bark was collected from tree trunks in the period of June 2-26, 2017. Concentrations of the heavy metals were determined in the barks by flame atomic absorption spectrometry (FAAS). On the basis of the research, it was determined that type of tree, distance from pollution source, elevation off the ground and the side of trunk from which bark was sampled all influence the research results. A comparison of the values of coefficient of variation CV demonstrated that the bark Quercus robur and Betula pendula is more heterogeneous, e.g. for Fe CV_{Quercus robur} is 48.0 % and CV_{Betula pendula} = 42.3 %, compared to Fagus sylvatica (CV_Fe = 22.6%). In order to limit the influence of environmental factors (e.g. air movement caused by vehicles and pedestrians) on the samples pollution level with analytes, it seems that the optimum level for collecting the samples is 1.5-2.0 m. It was demonstrated that deciduous tree bark can be used as bioindicator in assessing the pollution of atmospheric aerosol by heavy metals, due to its occurrence in urban areas. However, it is important to validate all stages of the analysis procedure that uses deciduous tree bark.