Deterministic Assessment Research Articles

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

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

Health risk assessment of heavy metals in nuts and seeds in Gansu Province, China

The popularity of nuts is growing, due to their nutritional properties and beneficial effects on human health. So they may be a source of exposure to heavy metals. To evaluate the health risks of consuming nuts to residents in Gansu Province, this study used ICP-MS to determine the Cd, Pb and Hg content in 151 nuts samples and conducted risk assessment by deterministic and probabilistic methods. The results showed that the median contents of Cd, Pb and Hg in nuts were 7.40E-3, 5.80E-2 and 9.00E-4 mg·kg−1, while in seeds were 3.89E-2, 4.47E-2 and 1.10E-3 mg·kg−1. Cd exceeded the Chinese maximum residue limits in 9.93 % (15/151) of the samples. At the P95 exposure level, the deterministic assessment showed that hazard quotients (HQs) of Hg, Cd, and Pb were below 1, hazard index (HI) was also below 1, cancer risk (CR) of Cd in nuts was below 10−4, but CR of Cd in seeds was above 10−4. In probability assessment, the HQs of Cd, Pb and Hg were less than 1, but the CR of Cd is greater than 10−4. In summary, Hg and Pb in nuts and seeds did not pose a health risk, but Cd may pose a carcinogenic risk to consumers.

Deterministic and probabilistic assessment of heavy metals in herbal teas sold in Lanzhou City, China

To evaluate the health risks of consuming herbal teas to residents in Lanzhou City, this study used ICP-MS to determine the Hg, Cd, and Pb content in 131 herbal tea samples (leaf, flower, and fruit) and conducted risk assessment by two methods. The Hg contents were all within safe limit of China, but the Cd and Pb levels in some samples were higher than the same limit. At the P95 exposure level, the ranking of heavy metals based on hazard quotient (HQ) was Pb > Cd > Hg in both methods. The deterministic assessment showed that HQs of Hg, Cd, and Pb were below 1, hazard index (HI) was also below 1, but cancer risk (CR) of Cd was above 10−4. In probability assessment, the HQs of Hg and Pb were less than 1, but the HQ of Cd had a certain probability of being greater than 1, and the CR of Cd is greater than 10−4. Therefore, we conclude that Hg and Pb in herbal teas may not pose a health risk, but Cd pose a health risk to consumers. Thus, measures should be taken to minimize the excessive accumulation of Pb and Cd in the cultivation and production process of floral tea.

A statistical interpretation of the EN 1993-1-10 brittle fracture criteria

EN 1993-1-10 contains tables for selection of steel quality class with respect to avoidance of brittle fracture. The conservatism of the method has not previously been examined statistically. The original verification of the method has been established basically on a deterministic assessment of 19 double edge cracked specimen tests. This verification has not accounted for e.g. constraint effects and the treatment of nominal data versus measured data is not fully satisfactory. Therefore, here the confidence of the procedure is examined statistically using more up to date information regarding the Charpy-V vs fracture toughness correlation and a quantitative assessment of the constraint effect. The study has two main purposes. First, to present a method by which consistent statistically defined criteria for a standard like EN 1993-1-10 can be developed and second, to obtain an approximate estimate of the conservatism contained in the present methodology. The statistical treatment is applied to the same 19 specimens originally used for the verification of the method.

Numerical Analysis of Harmful Environmental Impact of Accidental Explosion at a Hydrogen Filling Station Environmental Impact of an Accident Hydrogen Explosion at a Gas Station

The purpose of this study is to evaluate numerically the consequences of a hydrogen-air mixture explosion at a vehicle hydrogen filling station. The physical process of the explosion, which takes place after the hydrogen gas release into the air due to the accidental destruction of a number of high-pressure storage cylinders, is considered. The blast pressure wave moves in all directions from the epicenter of the accident, gradually losing its intensity and having a negative shock impact on the service personnel of the filling station and the structures of the surrounding buildings. The scale of the accident depends on the number of destroyed cylinders, which determines the size of the hydrogen-air cloud and the power of the explosion. The degree of negative consequences for the environment depends on the maximum overpressure in the blast wave front. Numerical obtaining of spatial pressure distributions in the area of the accident based on a hydrogen explosion mathematical modeling makes it possible to separate zones that are dangerous to human health and building structures strength. The direct problem of gas dynamics of combustion products of a hemispherical cloud of a stoichiometric hydrogen-air mixture in the surface layer of the atmosphere is considered. The mathematical model of an instantaneous hydrogen explosion takes into account the three-dimensional and non-stationary nature of the propagation of the explosion wave, the compressibility of the gas flow, the complex terrain, the shape and initial concentration of the cloud of hydrogen combustion products, and their thermodynamic parameters. The model makes it possible to obtain three-dimensional fields of maximum overpressure, which are the basis for deterministic assessment of the consequences of an accident for human health and the integrity of structures in the area of the explosion. The presented computer technology allows security experts to identify potential dangerous zones by means of mathematical modeling, recommend effective protective measures to mitigate or even eliminate the negative consequences of the blast wave environmental impact.

A Survey on Software Vulnerability Exploitability Assessment

Knowing the exploitability and severity of software vulnerabilities helps practitioners prioritize vulnerability mitigation efforts. Researchers have proposed and evaluated many different exploitability assessment methods. The goal of this research is to assist practitioners and researchers in understanding existing methods for assessing vulnerability exploitability through a survey of exploitability assessment literature. We identify three exploitability assessment approaches: assessments based on original, manual Common Vulnerability Scoring System, automated Deterministic assessments, and automated Probabilistic assessments. Other than the original Common Vulnerability Scoring System, the two most common sub-categories are Deterministic, Program State based, and Probabilistic learning model assessments.

Social determinants of health, the microbiome, and surgical injury.

Postinjury infection continues to plague trauma and emergency surgery patients fortunate enough to survive the initial injury. Rapid response systems, massive transfusion protocols, and the development of level 1 trauma centers, among others, have improved the outcome for millions of patients worldwide. Nonetheless, despite this excellent initial care, patients still remain vulnerable to postinjury infections that can result in organ failure, prolonged critical illness, and even death. While risk factors have been identified (degree of injury, blood loss, time to definitive care, immunocompromise, etc.), they remain probabilistic, not deterministic, and do not explain outcome variability at the individual case level. Here, we assert that analysis of the social determinants of health, as reflected in the patient's microbiome composition (i.e., community structure, membership) and function (metabolomic output), may offer a "window" with which to define individual variability following traumatic injury. Given emerging knowledge in the field, a more comprehensive evaluation of biomarkers within the patient's microbiome, from stool-based microbial metabolites to those in plasma and those present in exhaled breath, when coupled with clinical metadata and machine learning, could lead to a more deterministic assessment of an individual's risk for a poor outcome and those factors that are modifiable. The aim of this piece is to examine how measurable elements of the social determinants of health and the life history of the patient may be buried within the ecologic memory of the gut microbiome. Here we posit that interrogation of the gut microbiome in this manner may be used to inform novel approaches to drive recovery following a surgical injury.

Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential in The Niger Delta Region of Nigeria Using Standard Penetration Test-Based

Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential in The Niger Delta Region of Nigeria Using Standard Penetration Test-Based

Performance degradation of steel rebar considering corrosion spatial variability in concrete

The corrosion of steel bars is the main issue affecting the durability of reinforced concrete structures, which is nonuniform owing to the material properties and external environmental effects. In this study, the performance degradation of steel rebars in concrete is estimated considering corrosion spatial variability. With the aid of a three-dimensional measurement technique, a finite element model based on the scanning result was established to examine the corrosion effect on the tensile behaviour of the corroded bars, which was validated with the experimental results and digital image correlation observation. To assess the deformation behaviour of the corroded steels, a semi-analytical model was developed based on the cross-sectional area distribution and material properties. Subsequently, the spatial weight loss distributions with different degrees of corrosion were generated using a random field model. The model parameters were determined by combining engineering judgement and estimation of the experimental results. Finally, probabilistic model of degraded performance was established using the deterministic assessment and simulated steel weight loss distribution.

The Structural Reliability of the Usumacinta Bridge Using InSAR Time Series of Semi-Static Displacements

In recent years, Interferometric Synthetic Aperture Radar (InSAR) technology has been able to determine the semi-static behavior of bridges. However, most of the research about the use of InSAR in the monitoring of bridges has been applied only in deterministic assessments of their performance. Therefore, in the current manuscript, the Usumacinta Bridge, located in Mexico, was evaluated based on a probabilistic methodology to define structural reliability using images from Sentinel-1. In addition, a controlled experiment was developed using a corner reflector (CR) to evaluate the capabilities of InSAR for determining vertical displacements. In the trial, the CR was designed, oriented, and implemented, finding discrepancies concerning leveling of less than 2 mm. On the other hand, the case of the alternative probabilistic approach integrates the reliability of structures theory and probability density functions (PDFs) of displacements obtained via InSAR technology. In summary, the proposed study focused on the analysis of two years of vertical displacements and monthly velocities; then, implementing the alternative probabilistic approach, the reliability index (β) and probability of risk (PR) of the bridge were extracted, respectively. Based on the results of the experimental part of the paper, the displacements indicated maximum and minimum values of reliability index of 8.1 and 3.4, respectively. Within this context, the mean and standard deviation obtained were 5.9 and 1.4, respectively. On the other hand, the monthly velocities showed a maximum probability of risk of 2.61%, minimum value of 1.5 × 10−5%, mean of 0.4%, and standard deviation of 0.8%. Hence, the above-documented results indicate that the Usumacinta Bridge did not suffer any damage during its overloading condition period.

Enteral nutrition formulas: Analysis of phthalate esters and deterministic assessment of health risks

This study examined phthalate esters (PAEs) in pediatric enteral formula (PEF) samples in Turkey and their potential impact on consumers. Among the various types and forms of PEF sample, Type 5 had the highest total concentration of PAEs (71.52 µg/kg) for polimeric (PC) formulas, followed by Type 1 (60.33 µg/kg) for oligomeric (OC) formulas, and Type 1 (55.05 µg/kg) for monomeric (MC) formulas. However, no statistically significant differences were observed in the concentrations of PAEs among the different types of PEF samples (p > 0.05). The ranking of PEF samples based on their total PAEs levels was as follows: MC (54.94 µg/kg)> OC (54.05 µg/kg)> PC (53.32 µg/kg). DEHP, DINP, DNOP and DEP were the most abundant PAEs. Health risk assessments the carcinogenic risk associated with DEHP was determined to be at an acceptable cancer risk level (Grade: B) for all age and gender groups. Additionally, the dietary intake levels of each PAEs, including DEHP, DINP, DEP, and DBP, were found to be below the values established by the European Food Safety Authority for tolerable daily intake. Continuous monitoring and regulation are crucial to ensure PEF safety and reduce PAEs exposure risks.

Comprehensive Environmental and Health Risk Assessment of Soil Heavy Metal(loid)s Considering Uncertainties: The Case of a Typical Metal Mining Area in Daye City, China

Heavy metal(loid)s (HMs) in soils near mining sites often cause serious environmental and health issues. Accurately assessing soil HM risks and identifying priority pollutants are crucial for improving risk control efficiency with limited management costs and resources. Traditional deterministic assessments may yield biased results due to the imprecision and ambiguity of environmental data and assessment processes. To compensate for the deficiencies of deterministic assessment, a comprehensive probabilistic-fuzzy model was developed based on fuzzy theory, probability methods, the soil contamination risk (SCR) index, and a human health risk (HR) assessment framework. According to this model, the soil HM risk status in a typical mining area in China was evaluated. The results indicated that Cd and Cu significantly violated the relevant environmental guidelines and were considered priority metals for environmental risk (ER). Notably, Cd’s hazard predominantly manifested in a solid potential ecological risk (PER), whereas Cu’s environmental impact primarily manifested as a soil contamination risk (SCR). From the perspective of HR, soil HMs already pose a considerable threat to human health, with children facing greater HRs than adults. As was identified as a priority element for HRs, with carcinogenic and non-carcinogenic risks reaching unacceptable levels. Regarding general risk (GR), Cd and Cu ranked in the first gradient and As in the second gradient. Overall, the accumulation of soil HMs—especially Cd, Cu, and As—in the study area has posed a significant threat to the ecosystem and human health. The risks of other HMs (Pb, Zn, Cr, and Ni) are relatively low, but the superimposed risks of multiple HMs should not be ignored. The probabilistic–fuzzy model reduces the uncertainty of risk assessment, and the model integrates the environmental and health risks of HMs, providing more comprehensive risk information. The assessment results can serve as a reference for managers to develop targeted control strategies.

Deterministic assessment of the ecological vulnerability of coastal freshwater canals: A perspective on social awareness and conservation

Abstract. Khan NS, Islam MS, Bari JBA, Uddin M, Mashkova I, Kostryukova A, Trofimenko V. 2023. Deterministic assessment of the ecological vulnerability of coastal freshwater canals: A perspective on social awareness and conservation. Biodiversitas 24: 5179-5188. Inland freshwater canals are formed by geomorphological evolutions or artificially for communal welfare. The freshwater canal ecology differs mainly from rivers, estuaries, and the ocean for salinity variables, nutrient concentrations, morphological structure, and unique flora and fauna distribution. These canals and their aquatic organisms are very sensitive to surface runoff and direct sewage pollution. Thus, these freshwater canals become threats to society in case of contamination. The current study focused on the water quality, microalgae, and zooplankton communities in two renowned canals: Basurhat (BH) canal and Dotterhat (DH) canal in coastal Noakhali, Bangladesh. The study attempted to demonstrate these canals' aquatic and ecological status by evaluating plankton distribution and some important water quality parameters. Furthermore, a classic Palmer's algal organic pollution Index and wetland zooplankton Index were applied to determine the water quality according to species assemblages of freshwater algae and zooplankton, respectively. The present study identified 27 phytoplankton genera from Bashurhat Canal and 21 from Datterhat Canal. At the same time, 16 genera of zooplankton were observed with 2,269.09±52.12 ind/L and 4,588.54±40.79 ind/L from Bashurhat Canal and Datterhat Canal, respectively. The water quality differed from Bashurhat Canal and Datterhat Canal, where the highest temperature was found at Bashurhat Canal at 23.55±0.15°C and the lowest was 22.6±0.1°C. Moreover, the highest and lowest temperature was found from Datterhat Canal as 29.8±0.9°C and 29.67±0.78°C respectively. The highest transparency (cm), Dissolve Oxygen (mg/L), alkalinity (mg/L), free carbon dioxide (mg/L), ammonia (mg/L) and TSS (mg/L) were found as 29±1.0, 1.25±0.25, 58.76±0.26, 59.25±0.66, 8.25±0.25, 2.25±0.05 and the lowest were found 20.5± 0.5, 0.75±0.25, 27.73±0.49, 11.28±0.69, 8.15±0.15, 2.2±0.1 in Bashurhat Canal. Additionally, the highest transparency (cm), Dissolve oxygen (mg/L), alkalinity (mg/L), free carbon dioxide (mg/L), ammonia (mg/L), and TSS (mg/L) were found as 15.75±0.25, 1.85±0.50, 53.96±0.5, 55.09±0.8, 8.1±0.1, 4.0±0.1 and the lowest were identified 14.5± 0.5, 1.25±0.25, 23.1±0.4, 49.23±0.38, 7.65±0.50, 2.54±0.75 in Datterhat Canal. The study results indicate the deterioration of water quality in urbanized canals and that aquatic ecosystems face many long-term anthropogenic pressures. The current canal state requires measures to restore them. In addition, there is a need for strict control over the discharge of waste and pollutants from residential areas, fish markets, and hospitals.

Reliability-based Fire Protection of Structural Cables due to Deck Fires on Cable Supported Bridges

Cable supported bridges are typically part of community-critical infrastructure and therefore the consequences arising from extensive structural damage due to a fire and the subsequent operational discontinuity could be significant beyond the damage to the bridge itself and the cost of repairs. Bridge design standards generally do not provide guidance and hence fire resistance requirements are often informed by first principles assessments of the thermal and structural response of the structure to proposed fire scenarios. A deterministic assessment can provide a reasonable worst-case scenario but it does not allow bridge stakeholders to make informed decisions with regards to uncertainty and the low likelihood of fires occurring to identify the benefits of investments in structural fire protection. This is because the target reliability required for each bridge may be different depending on its characteristics, and the expected fire severity has a probabilistic nature. This research aims to fill this gap by undertaking a reliability-based analysis to assess the probability of structural failure by considering the probability of a fire of a given size occurring and the uncertainty in the incident location and wind. The methodology is demonstrated through the case study of an operational 450 m long cable supported bridge section and a fire scenario based on a liquid fuel tanker. Liquid tankers can result into two type of fire scenario: first, a fire being contained within the tanker; and secondly, a fire due to a pool on the deck. Both fire scenarios have been characterised and it was determined that the contained tanker scenario presents a more onerous design case owing to its more prolonged duration. A Monte Carlo analysis was undertaken for a total of 10,000 independent trials of the combination of the location of the fire and the wind direction. The frequency of the fire was also examined to establish the probability of structural failure of a cable. It was established that the inclusion of wind can sometimes reduce the estimated height at which cables may experience temperatures with the potential to cause cable failure. However, for a number of the cases, the estimated height can remain broadly similar (i.e. within a couple metres difference) to the worst-case calculated value. Based on this analysis, the influence of the required level of reliability as well the fire protection duration specification agreed with bridge stakeholders can be used to determine the height at which cable fire protection is necessary to reduce the probability of structural failure to a level acceptable to the stakeholders. This approach allows bridge designers and stakeholders to make informed decisions with regards to provision and extent of fire preventive/protective measures for cable supported bridges.

A new probabilistic assessment process for human health risk (HHR) in groundwater with extensive fluoride and nitrate optimized by non parametric estimation method.

Excessive amounts of fluoride (F-) and nitrate (NO3-) in groundwater pose a significant threat to human health. However, a quantitative approach to assessing the human health risks caused by these harmful substances is lacking. To optimize the probabilistic assessment process for human health risk (HHR), this study introduced kernel density estimation (KDE) into the stochastic simulation of F- and NO3- content in groundwater samples. The potential HHRs caused by F- and NO3- in Songyuan City were summarized by combining the probabilistic and deterministic assessments. This study found that the concentrations of F- and NO3- did not follow common probability density functions (PDFs), but the KDE method passed the Kolmogorov-Smirnov test with the critical value of 0.067 and 0.062, showing high fitting accuracy. Monte Carlo simulation indicated that the probability of NO3- for children and adult exceeding the standard is 21.95% and 15.14%, respectively, which is comparable with the results of the deterministic assessment, but the probabilistic assessment emphasized lower probability of HHRs in children caused by excess F-(4.14%). Global sensitivity analysis revealed that excessive NO3- in groundwater has the highest sensitivity of the HHR (>0.1), followed by other factors representing water use habits (>0.01). This study presents a refined probabilistic assessment method for HHR and provides a scientific reference for understanding the state of groundwater environments.

Comprehensive Investigation of Fluoroquinolone Residues in Apis mellifera and Apis cerana Honey and Potential Risks to Consumers: A Five-Year Study (2014-2018) in Zhejiang Province, China.

As a group of antibiotics largely used in China's animal husbandry, fluoroquinolone (FQ) residues in honey may pose potential threats to human health. This study performed a five-year investigation on the occurrence of FQ residues in honey in 521 Apis mellifera and 160 Apis cerana honey samples collected from Zhejiang Province, China and compared FQ residue profiles in honey with a subgroup of various factors. Deterministic and probabilistic risk assessments of exposure to FQ residues in honey were further conducted. Overall, four FQs were detected in 6.9% (47/681) of analyzed samples; banned norfloxacin with the highest level (7890 μg·kg-1) and detection frequency (4.9%) was the primary safety risk factor associated with honeybees raised in China. FQ detection frequency and concentration of rape honey was highest among four of the largest and most stable honeys (rape, acacia, chaste, and linden) in China. Processed honey from commercial sale channels had a significantly higher detection frequency of FQ residues than raw honey from apiaries. Deterministic assessment showed that the noncarcinogenic hazard quotient (HQ) value of the dietary intake of FQs by the local population was between 4.75 × 10-6 and 1.18 × 10-3, less than 1.0, indicating that FQ residues in honey posed a low risk for consumers. The order of the HQ value was ciprofloxacin > norfloxacin > enrofloxacin > ofloxacin. Probabilistic assessment showed that at P95, the HQ of FQs for the age groups of children, adolescents, adults, and older adults over 65 years ranged from 2.39 × 10-5 to 0.217, less than 1, and the exposure risk for adults was higher than for children and adolescents. Sensitivity analysis showed that FQ concentrations were the major contributors to health risks. Although a low risk was found, a strict hive management is needed for beekeepers regarding troubles of food safety, international trade, and human bacterial resistance.

The concentration of potentially toxic elements (PTEs) in Iranian rice: a dietary health risk assessment study.

In the present study, six potentially toxic elements (PTEs), including chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb), copper (Cu), and nickel (Ni), were determined in 41 domestic rice samples collected from Tehran using ICP-OES (inductively coupled plasma-optical emission spectrometry). The mean concentration of Cd, As, Cu, Pb, Cr, and Ni was found as 0.014 ± 0.01, 0.018 ± 0.005, 2.15 ± 1.84, 0.42 ± 0.31, 0.1 ± 0.16, and 0.48 ± 0.36 mg kg-1, respectively. Possible risks due to ingestion of PTEs via rice consumption for children and adults were assessed by Monte Carlo simulation. The 50th percentile of estimated Cr intake for children through domestic rice consumption exceeded the maximum tolerable daily intake. There was only a potential non-carcinogenic risk for single Cr exposure for children. The 95th percentile of the estimated hazard index (HI) for children and adults was 4.34 and 1.05, indicating a potential non-carcinogenic risk related to multiple PTE exposure. The lifetime cancer risk (ILCR) values derived from Cr, Ni, As, and Cd exposure exceeded the threshold value, indicating a carcinogenic risk due to PTEs' exposure. The deterministic assessment demonstrates that the Tehran population may be at risk through domestic rice consumption. This study indicates that risk related to the exposure to multiple PTEs through the consumption of rice in adults and children in Tehran is recognized as an important issue, thus supporting the importance of cumulative analysis of the risk of exposure to PTEs through food. Finally, national strategic environmental assessment and technological solutions for monitoring and protecting freshwater, soil, waste management, and chemicals as a global concern policy are needed for public health.

Assessment of Hg pollution in stream waters and human health risk in areas impacted by mining activities in the Ecuadorian Amazon.

Illegal gold mining activities have contributed to the release and mobilization of Hg and environmental degradation in many parts of the world. This study aims to determine the concentration of Hg in five provinces of the Amazon Region of Ecuador, in addition to assessing the risk to human health of exposed populations, applying deterministic and probabilistic methods. For this purpose, 147 water samples were collected in rivers and streams crossing and/or located near mining areas. As a result, 100% of the samples analyzed exceeded the maximum permissible limit (MPL) according to the water quality criteria for the preservation of aquatic life of the Ecuadorian regulations, while 7% of the samples exceeded the MPL for drinking water. On the other hand, considering the European Environmental Quality Standard (EQS) for surface water bodies, in our study, 100% of the samples exceed the maximum permissible limit (0.07µg/L), and with respect to the Canadian water quality guidelines, 35% of the samples exceed the permissible limit (0.001mg/l) for drinking water, and 100% of the samples exceed the limit for life in water bodies (0.0001mg/l). The risk assessment revealed that the probability of developing adverse health effects from exposure to Hg is below the recommended limits according to the probabilistic assessment; this is in relation to the criterion of residential and recreational use of water resources. However, it was identified that the child population doubles the acceptable systemic risk level according to the results of the deterministic assessment in the residential scenario. This information can be used by decision-makers to implement strategies to reduce Hg contamination and exposure of the population in Ecuadorian Amazonian rivers.

Frequently used pesticides and their metabolites residues in apple and apple juice from markets across China: Occurrence and health risk assessment

A large number of apples produced in China are consumed by people around the world every year. The pesticide residues in apples and apple juice are receiving more attention. Herein, 14 frequently used pesticides and 3 metabolites were selected as targets to investigate their residues in apples (120 samples) and apple juice (40 samples) in the markets across China, and the dietary intake risk for consumers was estimated. The monitoring results showed 91.7% of apple samples contained detectable pesticide residues, and six pesticides including thiamethoxam, carbendazim, pyraclostrobin, tebuconazole, chlorpyrifos and fenpyroximate exceeded limits of quantification with a detection rate of 63.3%, 61.7%, 22.5%, 21.7%, 8.3% and 2.5%, respectively. All pesticide residues were below their maximum residue limits (MRLs) in China. However, the banned pesticide chlorpyrifos in the Europe Union and the United States exceeded the local MRL (0.01 mg kg−1) in 7.5% of apples. No target chemicals occurred in juice samples. Risk assessment showed in deterministic assessment, the chronic and acute risk quotients of pesticides were ≤1.66 × 10−1% and 6.84%, respectively. The risk quotients of probability assessment were no more than 1.56%. The results indicated a negligible risk for consumers from consuming apples and apple juice from markets across China.

Watershed seasonality regulating vanadium concentrations and ecological risks in the coastal aquatic habitats of the northwest Pacific.

Vanadium is a component of different natural and industrial products and a widely used metal, which, nonetheless, has only garnered attention in recent years owing to its potential risks. Six sampling trips were conducted over different seasons and years, collecting 108 samples from rivers and 232 from the bays and analyzed using high-precision inductively coupled plasma mass spectrometry. This study investigated the sources, spatiotemporal characteristics, and risks of vanadium in the aquatic ecosystems of two typical bays of the Northwest Pacific that have strong links with vanadium-related industries. Likewise, the health and ecological risks were assessed using probabilistic and deterministic approaches. Overall, vanadium concentrations were higher in Jiaozhou Bay (JZB: 0.41–52.7 μg L−1) than in Laizhou Bay (LZB: 0.39–17.27 μg L−1), with concentrations higher than the majority of the worldwide studies. Vanadium-realted industries significantly impacted (p < 0.05) the metal concentrations in the rivers with 54.22% (40.73–150%) and 54.45% (27.66%–68.87%) greater concentrations in JZB and LZB rivers. In addition, vanadium exhibited significant seasonal variation, and higher values were quantified during the monsoon period at LZB owing to the greater catchment area. Impacted by smaller freshwater inputs, the post-monsoon period had substantial impacts on JZB, and vanadium in the rivers and bays was significantly higher during the winter. Despite some concentrations being higher than that indicated in the drinking water guidelines established by China, vanadium presents low to null risks to the population as per both approaches. Last, species with limited resilience are likely to face medium to high risks, with an incidence of 65–93% using the probabilistic method and 52–97% using the deterministic assessment.