Potential Health Risks Research Articles

Hydrogeochemical Insights into the Sustainable Prospects of Groundwater Resources in an Alpine Irrigation Area on Tibetan Plateau

The Tibetan Plateau is the “Asia Water Tower” and is pivotal for Asia and the whole world. Groundwater is essential for sustainable development in its alpine regions, yet its chemical quality increasingly limits its usability. The present research examines the hydrochemical characteristics and origins of phreatic groundwater in alpine irrigation areas. The study probes the chemical signatures, quality, and regulatory mechanisms of phreatic groundwater in a representative alpine irrigation area of the Tibetan Plateau. The findings indicate that the phreatic groundwater maintains a slightly alkaline and fresh status, with pH values ranging from 7.07 to 8.06 and Total Dissolved Solids (TDS) between 300.25 and 638.38 mg/L. The hydrochemical composition of phreatic groundwater is mainly HCO3-Ca type, with a minority of HCO3-Na·Ca types, closely mirroring the profile of river water. Nitrogen contaminants, including NO3−, NO2−, and NH4+, exhibit considerable concentration fluctuations within the phreatic aquifer. Approximately 9.09% of the sampled groundwaters exceed the NO2− threshold of 0.02 mg/L, and 28.57% surpass the NH4+ limit of 0.2 mg/L for potable water standards. All sampled groundwaters are below the permissible limit of NO3− (50 mg/L). Phreatic groundwater exhibits relatively good potability, as assessed by the entropy-weighted water quality index (EWQI), with 95.24% of groundwaters having an EWQI value below 100. However, the potential health risks associated with elevated NO3− levels, rather than NO2− and NH4+, merit attention when such water is consumed by minors at certain sporadic sampling locations. Phreatic groundwater does not present sodium hazards or soil permeability damage, yet salinity hazards require attention. The hydrochemical makeup of phreatic groundwater is primarily dictated by rock–water interactions, such as silicate weathering and cation exchange reactions, with occasional influences from the dissolution of evaporites and carbonates, as well as reverse cation-exchange processes. While agricultural activities have not caused a notable rise in salinity, they are the main contributors to nitrogen pollution in the study area’s phreatic groundwater. Agricultural-derived nitrogen pollutants require vigilant monitoring to avert extensive deterioration of groundwater quality and to ensure the sustainable management of groundwater resources in alpine areas.

Health Risk Assessment for Potential Toxic Elements in the Soil and Rice of Typical Paddy Fields in Henan Province

The accumulation of potential toxic elements in agricultural soil and rice is of particular concern in China. However, studies on the risk assessment of these elements in regional soil–rice systems remain limited. The aim of this study is to evaluate the pollution status and potential health risk of potential toxic elements in typical paddy soil and rice in Henan Province. A total of 80 soil samples and corresponding rice samples were collected to determine the contents of Cd, Pb, As, Cr, Cu, Zn, and Ni, and to assess their potential health risks to local consumers. Results showed that the average contents of these elements in soils were below the national risk screening values in GB15618-2018. Only the average content of Cr in rice exceeded the limit in GB 2762-2022 specified by the national food safety standard. The rates of exceeding the limits for Cd, Pb, As, and Cr in rice samples were 13.89%, 15.28%, 15.28%, and 27.78%, respectively. The health risk assessment indicated that rice intake for both adults and children caused carcinogenic and non-carcinogenic health risks to varying degrees. Local residents are advised to purchase rice from outside the study area to meet their daily needs and strictly regulate the pollution of potential toxic elements within the area.

Evolution of Reactive Organic Compounds and Their Potential Health Risk in Wildfire Smoke.

Wildfires are an increasing source of emissions into the air, with health effects modulated by the abundance and toxicity of individual species. In this work, we estimate reactive organic compounds (ROC) in western U.S. wildland forest fire smoke using a combination of observations from the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign and predictions from the Community Multiscale Air Quality (CMAQ) model. Standard emission inventory methods capture 40-45% of the estimated ROC mass emitted, with estimates of primary organic aerosol particularly low (5-8×). Downwind, gas-phase species abundances in molar units reflect the production of fragmentation products such as formaldehyde and methanol. Mass-based units emphasize larger compounds, which tend to be unidentified at an individual species level, are less volatile, and are typically not measured in the gas phase. Fire emissions are estimated to total 1250 ± 60 g·C of ROC per kg·C of CO, implying as much carbon is emitted as ROC as is emitted as CO. Particulate ROC has the potential to dominate the cancer and noncancer risk of long-term exposure to inhaled smoke, and better constraining these estimates will require information on the toxicity of particulate ROC from forest fires.

Trace antibiotic exposure affects murine gut microbiota and metabolism

Gut microbiota is important for host metabolism regulation. Antibiotic exposure disturbs this regulation by affecting the microbiome. Trace levels of antibiotics in water have been widely reported and the impact on gut microbiota remains understudied. We provide evidence of trace antibiotic exposure affecting the host's gut microbiota using a mouse model exposed to trace amounts of azithromycin (AZI) or ciprofloxacin (CIP) in drinking water. AZI exposure in males changed the distribution of gram-positive (Firmicutes and Bacteroidetes) and gram-negative (Proteobacteria, Fusobacteria, and Verrucomicrobia) bacteria at an early age. Both AZI and CIP resulted in abnormal microbiota maturation. Additionally, the production of short-chain fatty acids (SCFAs), including acetate, butyrate, and propionate, in females is affected. Serum hormone and metabolome levels shifted after trace antibiotic exposure. AZI and CIP exposure broadly disrupted original host-microbe interaction relationships between the gut microbiota and SCFAs or serum metabolites. In this study, we demonstrated that trace antibiotic exposure was associated with extensive gut microbiota and metabolism perturbation in mice and that the potential health risks in susceptible populations should be considered.

Validity of self-reported number of pregnancies and maternal age at first birth among females attending organized mammographic screening.

Reproductive history conveys information about potential health risks later in adulthood. This study aimed to examine the validity of self-reported number of pregnancies and maternal age at first birth (AFB) among females attending BreastScreen Norway. Participants were identified through the Janus Serum Bank cohort in Norway and were eligible for this cross-sectional validation study if they participated in a health survey issued by BreastScreen Norway between 2006 and 2015. Retrospective self-reported survey information on number of pregnancies and AFB in years was validated against prospectively collected information from the Medical Birth Registry of Norway (MBRN) using the Spearman rank (rs) and intraclass correlation coefficients (ICC) with 95% confidence intervals (CI). After exclusions, 51,598 subjects were included in the analysis on number of pregnancies and 46,919 in the analysis on AFB. On average, study subjects were 59-60 years old when completing the health survey and had become first-time mothers roughly 36 years earlier. Survey-based information about number of pregnancies was highly correlated and demonstrated high agreement with the registry data (rs=0.967, 95% CI 0.964-0.969; ICC=0.884, 95% CI 0.882-0.885). Survey-based information about AFB demonstrated even higher correlation and very high agreement with the registry data (rs=0.975, 95% CI 0.973-0.976; ICC=0.974, 95% CI 0.974-0.975). Retrospectively recalled survey-based information about number of pregnancies and AFB was highly accurate when validated against prospectively collected information in the MBRN. These survey-based data are valuable for future epidemiological research, and linkage to the MBRN may not be required when these data are available.

Evaluation of selected minerals and health risk and proximate analysis of wasawasa (a street food)

This study was carried out to determine the proximate composition and the potential heavy metal health risk that may be associated with the consumption of wasawasa, a dish made from locally milled yam peels, by examining the presence of six metals (iron, nickel, chromium, sodium, and magnesium and potassium) in samples procured. Sixteen (16) samples of ready-to-eat wasawasa were collected from Aboabo, Manhyia, Sawaba, Asawase, Adenyase, and Ayigya in Kumasi, since these are the communities where wasawasa is mainly produced, sold, and consumed. The samples were digested with a nitric, perchloric, and sulfuric acid mixture and analyzed using a microwave plasma atomic emission spectrometer (Agilent 4210 MP-AES). The average concentrations of metals were Na (8506.88 mg/kg), Mg (222.63 mg/kg), Fe (84.45 mg/kg), Cr (2.31 mg/kg), K (1702.08 mg/kg, and Ni (1.12 mg/kg). Proximate analysis was used to determine Protein, fat, ash, moisture, and fiber content of the local wasawasa, which were found to be 15.667 %, 0.45 %, 1.00 %, 27.54 %, and 0.41 %, respectively. The hazard index of the heavy metals (Fe, Ni and Cr) for both adults and children were each greater than one, indicating the population is likely to experience non-carcinogenic effects from the consumption of wasawasa.

Evaluation of Taraxacum officinale phytoconstituents as potential JNK1 inhibitors: Perspectives from ADMET, molecular docking, molecular dynamics, and density functional theory

The impact of activated c-Jun N-terminal kinase isoform JNK1 chemical pathways in insulin biosynthesis poses a potential health risk of glucose intolerance. Blocking the activity of JNK1 is a promising route for the design of anti-diabetic drugs and associated metabolic syndromes. In this study, 17 extracts of Taraxacum officinale were chosen to bind JNK1 and ascertain their modulatory activity. We employed molecular dynamics, density functional theory and three docking approaches: standard precision, extra precision and quantum polarized ligand docking. The best binding free energy results were obtained from the quantum polarized ligand docking, with myricetin (1) showing a docking score of -10.464 kcal/mol, while quercetin (2) and daphnetin (3) displayed values of -9.769 and -7.136 kcal/mol respectively. Following this, 100 ns molecular dynamics simulations with Desmond showed stabilization average root mean square deviations of 2.34, 2.87, and 2.88 Å for myricetin, quercetin and daphnetin. Further, molecular dynamics revealed complexes of myricetin (ΔG = -38.81 kcal/mol) and quercetin (ΔG = -34.99 kcal/mol) as the most stable inside the JNK1 interface. The energy gaps for myricetin, quercetin and daphnetin were estimated to be 6.17, 6.00 and 6.53 eV employing the M06–2X functional in PCM solvation. Further, myricetin showed the strongest intramolecular hydrogen bonding with -13.06 kcal/mol. This study provides insights into possible anti-type-2 diabetes properties of Taraxacum officinale targeting JNK1.

Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Beef and Chicken Satay and their Potential Health Risk

Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Beef and Chicken Satay and their Potential Health Risk

Tailored Environment-Friendly Reverse Type-I Colloidal Quantum Dots for a Near-Infrared Optical Synapse and Artificial Vision System.

Colloidal quantum dots (QDs) are emerging as potential candidates for constructing near-infrared (NIR) photodetectors (PDs) and artificial optoelectronic synapses due to solution processability and a tunable bandgap. However, most of the current NIR QDs-optoelectronic devices are still fabricated using QDs with incorporated harmful heavy metals of lead (Pb) and mercury (Hg), showing potential health and environment risks. In this work, we tailored eco-friendly reverse type-I ZnSe/InP QDs by copper (Cu) doping and extended the photoresponse from the visible to NIR region. Transient absorption spectroscopy analysis revealed the presence of Cu dopant states in ZnSe/InP:Cu QDs that facilitated the extraction of photogenerated charge carriers, leading to an enhanced photodetection performance. Specifically, under 400 nm illumination, the Cu-doped ZnSe/InP QDs-based PDs presented a broadband photodetection ranging from ultraviolet (UV) to NIR, with a responsivity of 70.5 A W-1 and detectivity of 2.8 × 1011 Jones, surpassing those of the undoped ZnSe/InP QDs-based PDs (49.4 A W-1 and 1.9 × 1011 Jones, respectively). More importantly, the ZnSe/InP:Cu QDs-PDs demonstrated various synapse-like characteristics of short-term plasticity (STP), long-term plasticity (LTP), and learning-forging-relearning under NIR light illumination, which were further used to construct PD array devices for simulating the artificial visual system that is available in prospective optical neuromorphic applications.

Wildlife trade at Belén and Modelo market, Peru: defining a baseline for conservation monitoring

IntroductionDomestic wildlife markets have important nutritional, medicinal, cultural, and financial significance for local communities, but the scale and diversity of wildlife trade that passes through them is also associated with negative impacts on biodiversity, poor animal welfare, and potential human health risk. To design, and monitor the effectiveness of, interventions to ameliorate such impacts, an understanding of the species sold at the markets and their purpose is required, together with a robust (and potentially flexible) baseline. Here we focus on Belén (the largest open wildlife market in the Peruvian Amazon) and Modelo market, in Iquitos, Peru.MethodsWe surveyed wildlife products for sale at both markets approximately weekly over a year, using two different survey methods (open and discreet). To provide a baseline to support future conservation monitoring, we estimated a number of different market metrics (including indices of product availability, volume (observed per survey), and price), for the most frequently observed species ‘groups’, and compared indices of trade volume with daily river water levels. To provide a complete understanding of the range of species involved, we also described all threatened species recorded at the markets, the products sold, and their uses, including those that were only observed occasionally.ResultsBoth markets sold predominantly wild meat, and some pets; at Belén Market >30% observations were of decorative, spiritual, or medicinal products. At least 71 unique species (including mammals, reptiles, birds, and invertebrates) were observed in total. The most frequently observed species ‘groups’ were: lowland paca, peccaries, caiman, river turtles, boas, yellow footed tortoise, parrots, and brocket deer. 27.7% of species were threatened or Near Threatened globally or nationally but there was no evidence that discreet surveys increased their detection. Daily river water levels were positively correlated with indices of trade volume for lowland paca, caiman, and yellow-footed tortoise, and negatively correlated with indices of trade volume for parrots and river turtle eggs.DiscussionBeyond providing a comparative dataset, and insights regarding the apparent availability and value of a diversity of products (including food items, live pets, and other decorative, spiritual, and medicinal items), we suggest that simulations using these data could be used to optimize future monitoring efforts. Finally, our observations of correlations of per survey trade volumes of some species with daily river water levels in Iquitos may inform optimal time of year for species- specific surveys.

Assessment of manganese accumulation in dryland wheat grains via plastic film mulching: Implications for human health risk in multi-site studies

Crop manganese (Mn) accumulation and the associated human health risks stemming from excessive intake of high Mn crop foods have attracted attention. However, there is limited information available concerning the impact of plastic film mulching (PFM) on Mn concentration in cereal grains and the health risks associated with Mn intake by the human body. Field experiments were conducted from 2014 to 2016 at seven sites in the drylands of a typical wheat-growing region in China to assess the effect of PFM on grain Mn concentration, Mn accumulation and distribution in winter wheat plants, and the potential risk of Mn intake and optimal grain intake for human health. The multi-site study results revealed that grain Mn concentration and bioavailability were significantly higher under PFM compared to no mulching. Similarly, PFM was found to enhance aboveground Mn accumulation at the anthesis stage by 17.5 %, Mn harvest index by 3.9 %, grain Mn accumulation by 28.9 %, and available Mn concentration in the soil by 10.9 %. The increased uptake and accumulation of Mn in wheat plants, leading to elevated grain Mn concentration, were primarily attributed to the improved availability of Mn and moisture in the soil under PFM treatment. Furthermore, a health risk assessment indicated that long-term consumption of whole wheat grains from PFM treatment could potentially pose a non-carcinogenic risk of Mn for children and adolescents residing in rural areas. Therefore, this study established upper limits for daily consumption of whole wheat grains based on the specific needs of local residents. The findings of this research underscore the potential health risks associated with consuming grain crops grown in PFM crop production systems.

Determination of antibiotic residues in pork meat from Northeast Mexico by UPLC-MS

ABSTRACT In this study, the aim was to identify and quantify antibiotic residues in pork meat samples of supermarkets and butcher shops of two main cities in northeast Mexico, using Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS). The results shown seven antibiotic residues detected in the samples. Ampicillin was the main antibiotic with a higher positive rate (>59%) in supermarkets and butcher shops. Tetracycline and sulfamethazine had a high positive rate (>25%). Finally, the quantification of antibiotics shown a high positive rate of samples that exceed the minimum residues limits (MRL). The high positive rate of antibiotic residues in this study suggests an inadequate management in the food industry and represents a potential risk for the human health in the northeast from Mexico.

Contaminants and residues have varied distributions in large volumes of wheat

Analysis of bulk wheat consignments for naturally-occurring contaminants and residues from plant protection products is common, and helps manage potential health risks to consumers. The heterogeneous distribution of some mycotoxins in wheat has been described, however the distribution of other contaminants and residues has not yet been reported. This study characterized distributions of deoxynivalenol, ochratoxin A, ergot alkaloids, cadmium, and glyphosate in nine large consignments of wheat by analysing composite samples representing sub-lots prepared from increments obtained during the entire loading process. The widest span of concentrations within a consignment occurred for ochratoxin A (<0.5–22.9 µg/kg) and ergot alkaloids (0.009–0.486 mg/kg), followed by deoxynivalenol (<0.05–0.76 mg/kg) and glyphosate (<0.3–5.01 mg/kg), and then cadmium (0.022–0.102 mg/kg). Experimental semivariograms were plotted to model the spatio-temporal correlation of analytes within consignments during loading. Analyses demonstrated that distributions of contaminants and residues within a particular consignment differed, and that distributions of a particular contaminant or residue differed among consignments. The results indicate that sampling during only a portion of a loading or unloading process can result in a composite sample that is not representative of the consignment and thus increase the risk of misclassifying a consignment as compliant.

Trends in socioeconomic inequality in e-cigarette use among adolescents in South Korea.

The global rise in e-cigarette use among adolescents is alarming, with associated socioeconomic inequalities posing potential public health risks. This study examined trends in the socioeconomic inequality in e-cigarette use among South Korean adolescents to inform future regulatory directions. Socioeconomic inequalities in e-cigarette use among Korean adolescents were assessed using data from the Korea Youth Risk Behavior Web-based Survey (KYRBS) from 2011 to 2023. The Concentration Index, a well-established method for measuring health inequalities, was employed. Additionally, this study investigated how the smoking behaviors of family members and friends influence socioeconomic inequality in e-cigarette use among Korean adolescents, using a decomposition analysis. The Concentration Index values showed a clear, fluctuating downward trend over 13 years, from -0.12 (95% CI: -0.13 - -0.10) in 2011 to -0.24 (95% CI: -0.26 - -0.21) in 2023. Decomposition analysis revealed that smoking among peer groups, including friends and siblings, was the primary contributor to socioeconomic inequality in e-cigarette use, followed by maternal smoking. Socioeconomic inequalities in adolescent e-cigarette use in South Korea are widening, particularly among low socioeconomic status groups. The impact of peer groups on socioeconomic inequalities in e-cigarette use among adolescents is concerning.

Epithelial barrier dysfunction and associated diseases in companion animals: Differences and similarities between humans and animals and research needs.

Since the 1960s, more than 350,000 new chemicals have been introduced into the lives of humans and domestic animals. Many of them have become part of modern life and some are affecting nature as pollutants. Yet, our comprehension of their potential health risks for both humans and animals remains partial. The "epithelial barrier theory" suggests that genetic predisposition and exposure to diverse factors damaging the epithelial barriers contribute to the emergence of allergic and autoimmune conditions. Impaired epithelial barriers, microbial dysbiosis, and tissue inflammation have been observed in a high number of mucosal inflammatory, autoimmune and neuropsychiatric diseases, many of which showed increased prevalence in the last decades. Pets, especially cats and dogs, share living spaces with humans and are exposed to household cleaners, personal care products, air pollutants, and microplastics. The utilisation of cosmetic products and food additives for pets is on the rise, unfortunately, accompanied by less rigorous safety regulations than those governing human products. In this review, we explore the implications of disruptions in epithelial barriers on the well-being of companion animals, drawing comparisons with humans, and endeavour to elucidate the spectrum of diseases that afflict them. In addition, future research areas with the interconnectedness of human, animal, and environmental well-being are highlighted in line with the "One Health" concept.

Quantum Dots-caused Retinal Degeneration in Zebrafish Regulated by Ferroptosis and Mitophagy in Retinal Pigment Epithelial Cells through Inhibiting Spliceosome.

Quantum dots (QDs) are widely used, but their health impact on the visual system is little known. This study aims to elucidate the effects and mechanisms of typical metallic QDs on retinas using zebrafish. Comprehensive histology, imaging, and bulk RNA sequencing reveal that InP/ZnS QDs cause retinal degeneration. Furthermore, single-cell RNA-seq reveals a reduction in the number of retinal pigment epithelial cells (RPE) and short-wave cone UV photoreceptor cells (PR(UV)), accompanied by an increase in middle- and long-wave cone red, green, and blue photoreceptor cells [PR(RGB)]. Mechanistically, after endocytosis by RPE, InP/ZnS QDs inhibit the expression of splicing factor prpf8, resulting in gpx4b mRNA unsplicing, which finally decrease glutathione and induce ferroptosis and mitophagy. The decrease of RPE fails to engulf the damaged outer segments of PR, possibly promoting the differentiation of PR(UV) to PR(RGB). Knockout prpf8 or gpx4b with CRISPR/Cas9 system, the retinal damage is also observed. Whereas, overexpression of prpf8 or gpx4b, or supplement of glutathione can rescue the retinal degenerative damage caused by InP/ZnS QDs. In conclusion, this study illustrates the potential health risks of InP/ZnS QDs on eye development and provides valuable insights into the underlying mechanisms of InP/ZnS QDs-caused retinal degeneration.

Arsenic, cadmium, and chromium concentrations in contrasting phosphate fertilizers and their bioaccumulation by crops: Towards a green label?

Potentially toxic elements such as arsenic (As), cadmium (Cd), and chromium (Cr) are severely regulated in fertilizers and deserve continuous investigation. Phosphate-derived Cd has been a stepping-stone toward achieving sustainable and safe worldwide food production, especially after a new regulation aiming for reduced limits of Cd in P fertilizers (EU, 2019/1009). Three pot experiments were conducted to assess the variability of As, Cd, and Cr concentrations - with a particular focus on Cd - from monoammonium phosphates (MAP 1, MAP 2, and MAP 3 from different geographic origins) and their accumulation in limed and unlimed soils, and contrasting crops, representing staple food and significant sources of these elements for humans (i.e., potato, tobacco, and rice). A diverse array of sensitive techniques for trace elements determination were used to reveal the highest level of Cd of MAP 3 (20.71 mg kg−1 MAP), which loaded the highest amounts of this element to the soil matrix and solution, plant shoots, and xylem sap, contrasting with results for MAP 1 (0.87 mg kg−1 MAP), which has almost ten times less Cd than that required for low-Cd labeling of P fertilizers (≤20 mg Cd kg−1 P2O5). MAP 3 also had the highest Cr concentration (139.3 mg kg−1 MAP). Among crops, rice accumulated 16-fold less Cd than potato plants. Liming decreased Cd in tobacco and potato shoots up to 35%. Moreover, reductions of about 20% were also observed for Cd accumulation in tubers and sap. Conversely, Cd from MAP 3 was always much more accumulated in soil solution, achieving up to 20 μg L−1, while values < 5 μg L−1 (i.e., a groundwater limit) were obtained from MAP 1. Our findings may be used as a reference in developing green labels for fertilizers in scenarios where Cd accumulation represents a potential risk for soil and human health.

Potential health risks of inhaling hazardous chemical exposures at fuel stations: a pilot study in a hot, arid environment

In recent years, there has been a growing focus on the issue of exposure to hazardous chemical compounds and the potential health risks associated with them. Fuel stations play a critical role in society, supporting the transportation industry and serving the general public. However, the routine activities at these stations expose workers and customers to dangerous chemical compounds, posing potential health risks. As part of a pilot study, the exposure of workers and customers to hazardous chemical compounds at fuel stations in Kuwait, characterized by its hot and arid environment, was investigated. The study specifically looked at volatile organic compounds (VOC) concentration and their effects on human health. Three hundred-eight air samples were collected in a hot, arid environment, focusing on fuel stations. Two sampling methods were used in this pilot study: personal inhalation exposure using active sampling and workplace air sampling using passive sampling. Samples were collected in fuel filling areas, indoor control rooms, and through personal exposures, adhering to ISO procedures (EPA TO-17). The study also assessed the non-carcinogenic and carcinogenic risks to human health to potential exposure to hazardous hazardous chemicals. The findings revealed that hazardous chemicals levels in the pump area were lower than those in the indoor control rooms. Workers’ inhalation exposure to hazardous chemicals remained below the international occupational exposure limit (OEL). However, the study identified unsafe inhalation exposure levels to Benzene, which could have adverse carcinogenic effects. In contrast, exposure to ethylbenzene was found to be within safe limits, with no associated carcinogenic effects. This study underscores the importance of identifying the risks associated with exposure to hazardous chemical compounds to minimize human health risks and promote a safe working environment.

Environmental and human health risk of potentially toxic metals in freshwater and brackish water Nile tilapia (Oreochromis niloticus) aquaculture.

Tilapia aquaculture is rapidly expanding worldwide, particularly in Bangladesh. However, metal pollution in aquaculture presents significant environmental and human health risks. This study aimed to evaluate the concentrations of 13 potentially toxic metals (As, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, Mn, Se, and Zn) in Nile tilapia (Oreochromis niloticus), surface water, and sediment from freshwater and brackish water aquaculture ponds. The study also assessed the associated environmental and human health risks. Samples of tilapia, water, and sediment were collected between October and November 2021 and analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The estimated daily intake (EDI) of As, Cr, Pb, Se, and Zn in tilapia muscle of both freshwater and brackish water, as well as Cd and Ni in brackish water, exceeded recommended EDI values. The Target Hazard Quotient (THQ) was less than 1 for most metals, except for As in brackish water tilapia and Cr in both freshwater and brackish water tilapia, indicating potential health risks. The Target Cancer Risk (TR) values for As in both freshwater and brackish water tilapia, and for Cr and Ni in freshwater tilapia, exceeded acceptable ranges. While the concentrations of metals in surface water of both freshwater and brackish water tilapia farms varied, all mean concentrations were below WHO recommended limits. The contamination factor (Cf) values were less than 1 for all metals in both types of aquaculture ponds, except for Zn in freshwater sediment and Se in brackish water sediment. Additionally, the calculated risk indices including the Pollution Load Index (PLI), Geoaccumulation Index (Igeo), Ecological Risk Factor (Er), and Potential Ecological Risk Factor (PER) for sediment were below the risk thresholds values (PLI < 1, Igeo < 0, Er < 40, and PER < 150). The significant positive correlations were found between tilapia muscle and the sediment of the respective ponds for arsenic (As) (ρ= 0.8, p<0.002) and Cr (ρ= 0.7, p<0.02). Although the levels of studied metals in water and sediment from freshwater and brackish water aquaculture ponds were generally within recommended guidelines, this study underscores the need for continuous monitoring and preventative measures, particularly to address elevated levels of As and Cr in tilapia muscle, which may pose potential risks to human health.

Determination of concentration and risk assessment of toxic metals in the settled dust from school yards of Mashhad metropolis.

The present study aims to measure the values of metal pollutants in the dust of schools in Mashhad metropolis, determine the source of metal pollution, evaluate the degree of pollution, assess the health risk (carcinogenicity/non-carcinogenicity) and evaluate the potential ecological risk. For this purpose, after measuring the concentration of metals using an inductively coupled plasma-mass spectrometer, from various indices including Geoaccumulation Index (Igeo), Pollution Load Index (PLI), Contamination Factors (CF), Potential Ecological Risk Index (PERI), Enrichment Factor (EF), and Health Risk Indices such as Hazard Quotient (HQ), Hazard Index (HI), Carcinogenic Risk (CR) were used. The average concentrations of iron, arsenic, cadmium, chromium, copper, nickel, lead, vanadium and zinc (Fe, As, Cd, Cr, Cu, Ni, Pb, V and Zn) were 6361.50, 5.96, 0.59, 61.89, 37.13, 61.31, 28.93, 25.64 and 142.00µgg-1, respectively. Based on CF, PLI and Igeo indices, most of the findings for the studied elements were at the low pollution level. The results also showed that the most likely origin of the studied metals was anthropogenic sources. The results of PERI indices showed that potential ecological risk at only one of the collection sites. In contrast, a high ecological risk was obtained for Cd. Hazard Index values were below safe levels for all studied elements. CR levels for elements were also classified as negligible and acceptable or tolerable risk, although the highest CR value for Cr indicated possible harm to humans. The findings showed the need for more attention and continuous monitoring of the concentration of metals, especially chromium, to announce a possible warning and prevent their harmful effects. It should be noted that the present study is the first research with mentioned objectives in Mashhad city and also in Khorasan Razavi province.