Human Exposure Assessment Research Articles

Multi-residue analytical method development and dietary exposure risk assessment of 345 pesticides in mango by LC-Q-TOF/MS

Mango is attracting increasing global attention for its superior flavor and nutritional benefits. However, the use of pesticides has resulted in a threat to its quality, safety, and human health due to their inevitable residue. There is an urgent need for advanced technologies that can efficiently and sensitively analyze a wide range of pesticides. In this study, a high-throughput screening and quantification method for 345 pesticides in mango was established by applying a modified QuEChERS method combined with liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF/MS). A response surface methodology (RSM) optimized the critical parameters for extracting various pesticides in 1% acetic acid-acetonitrile (v/v) using MgSO4, PSA, C18, and GCB as the adsorbents. The proposed method was successfully validated and applied to the quantitative detection of pesticide residues in 73 mango samples from Hainan. The study found pesticide residues in 95.9% of mango samples, of which 3 samples had residue concentrations in excess of the Chinese maximum residue limit. A total of 24 pesticides were detected, with detection percentages ranging from 1.4% (Thiabendazole) to 41.1% (Pyraclostrobin). Considering the possible health risks related to pesticide residues, risk assessment of human exposure to pesticides via intake of mango was evaluated. The acute and chronic dietary exposure risks related to pesticide residues in mango were accepted. In conclusion, this study provides a powerful platform for monitoring multiple pesticides in mango. First, it can promote the rational use of pesticides, and second, it can help consumers to assess the risk of dietary exposure to pesticide residues.

Appraisal of contamination, hydrogeochemistry, and Monte Carlo simulation of health risks of groundwater in a lithium-rich ore area.

This study incorporated hydrogeochemical facies, the entropy-weighted water quality index (EWQI), multivariate statistics, and probabilistic human exposure assessment to investigate hydrogeochemistry, analyze groundwater quality, and estimate potential risks to human health in a lithium-rich ore area (Jadar River basin, Serbia). The findings designated the Ca·Mg-HCO3 hydrogeochemical type as the predominant type of groundwater, in which rock weathering and evaporation control the major ion chemistry. Due to the weathering of a lithium-rich mineral (Jadarite), the lithium content in the groundwater was very high, up to 567mg/L, with a median value of 4.3mg/L. According to the calculated EWQI, 86.4% of the samples belong to poor and extremely poor quality water for drinking. Geospatial mapping of the studied area uncovered several hotspots of severely contaminated groundwater. The risk assessment results show that groundwater contaminants pose significant non-carcinogenic and carcinogenic human health risks to residents, with most samples exceeding the allowable limits for the hazard index (HI) and the incremental lifetime cancer risk (ILCR). The ingestion exposure pathway has been identified as a critical contaminant route. Monte Carlo risk simulation made apparent that the likelihood of developing cancerous diseases is very high for both age groups. Sensitivity analysis highlighted ingestion rate and human body weight as the two most influential exposure factors on the variability of health risk assessment outcomes.

Source and Bioavailability of Quaternary Ammonium Compounds (QACs) in Dust: Implications for Nationwide Exposure in China

Quaternary ammonium compounds (QACs), widely used in various disinfectants products during the COVID-19 Pandemic, raised the concerns on their exposure and health effect. To date, the sources of QACs in indoor environments have been largely ignored. Additionally, there is no information on the nationwide human exposure assessment of QACs in China after the COVID-19. Herein, analysis of QACs in household products, including personal care (n=27), cleaning (n=6) and disinfection products (n=11) from different manufacturing companies further confirmed there are extensive application of QACs in household products, raising their potential exposure to humans. QACs were frequently detected in indoor dust samples (n=370) from 111 cities of 31 provinces/municipalities across China, with median concentration of 6778ng/g. Benzalkyldimethylammonium compounds (BACs) and alkyltrimethylammonium compounds (ATMACs) were identified as the dominant QACs in dust samples, with the proportions of 44% and 46%, respectively. The in vivo bioavailability experiment (C57BL/6 male mice) showed that the relative bioavailability (RBA) of QACs through dust ingestion ranged from 5.08% to 66.3% and 60.3% to 118% in the low and high-dose group, respectively. Compared to the pre-adjustment scenario of RBA values, the exposure risk of QACs was overestimated by 2.23 – 5.14 times.

Biomonitoring of exposure to metals and metalloids using toenail and fingernail sampling in individuals from artisanal gold mining areas in Mali

Artisanal gold mining can release metallic elements in the environment that can result in occupational and environmental exposures. This pilot study aimed to assess exposure to metals and metalloids from fingernail and toenail samples in artisanal gold mine workers, inhabitants of a mining and non-mining village in Mali. As it can be particularly challenging to collect and transport biological samples from remote areas, nail sample collection was tested as a potential choice for multielement biomonitoring. A convenience sampling of 315 individuals was performed equally distributed in each location group (105 per location) and stratified by populational group (male adults, female adults, and people <18 years). Toenail and fingernail samples were collected from each participant and twenty-one elements (aluminum (Al), arsenic (As), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), gallium (Ga), iron (Fe), lithium (Li), lead (Pb), manganese (Mn), nickel (Ni), selenium (Se), silver (Ag), strontium (Sr), thallium (Th), uranium (u), vanadium (v) and zinc (Zn)) were quantified. Concentrations of 12 elements in fingernails and/or toenails were significantly higher in the mine worker group, in particular As, Co and Cu in both toenails and fingernails. In the mine worker group specifically, As concentrations in both fingernails and toenails were higher in males. Most metals also had a strong positive correlation overall. Both fingernails and toenails appear as interesting biomonitoring matrices for multielement exposure assessment with an impact of different variables, such as mining exposure and sex, on internal levels. The study also highlighted the importance of further human exposure assessment related to artisanal gold mining in Mali, including the identification of other environmental sources of exposure.

Organophosphate ester exposure in nail salons: Health implications for workers

Organophosphates esters (OPEs) have become a preferred alternative in nail polish as plasticizers due to health concerns over previously used additives like dibutyl phthalate. However, the true extent of nail technicians' exposure to OPEs is largely unknown. This study shows that nail salon workers are significant exposed to OPEs, with varied concentrations found in air, dust, masks, and urine. The total concentrations of 11 OPEs in ultrasonic personal air samplers (UPAS) ranged from 251 to 1007 ng/m³, and in air conditioner filter dust from 371 to 14473 ng/g. Triphenyl phosphate (TPHP) was the most abundant compound found in the nail polishes used in these salons. On average, the concentrations of TPHP and diphenyl phosphate (DPHP) in workers' urine after work were 5.2 and 1.8 times higher than those before work, respectively. Two nail salons that had the highest nail polish usage also had very high concentrations of TPHP in surgical masks, dust, and UPAS. TPHP concentrations in workers’ urine after work were 19 and 13 times those before work, respectively, in these two salons. Human internal exposure assessment showed that the average exposure dose of TPHP after work was 1.8 times higher than that before work. On average, use of masks reduced OPEs in urine by 77%. In conclusion, frequent mask replacement is highly recommended, especially in long working circumstances. Without regular replacement, masks may accumulate OPEs from the air, potentially becoming another source of human exposure to OPEs. Therefore, more attention should be paid to the occupational exposure of nail salon workers to OPEs, particularly considering that most practitioners in this industry are young women of reproductive age.

Impact of Kitchen Natural Gas Use on Indoor NO2 Levels and Human Health: A Case Study in Two European Cities

Natural gas (NG) is commonly used in kitchens, powering stoves, ovens, and other appliances. While it is known for its efficiency and convenience, NG contributes to the release of nitrogen dioxide (NO2) and can have significant implications for human health. In this study, the importance of the use of NG in kitchens on human exposure to NO2 was analyzed. An extensive literature review in the field was conducted, and the NO2 levels were assessed in kitchens with NG cookers in Aveiro and electric cookers in Porto, both in Portugal. Higher levels of NO2 were found in kitchens in Aveiro, where NO2 levels outdoors are lower than in Porto. This pollutant can spread to other rooms, especially when ventilation is lacking, which is particularly concerning during colder seasons and at night. As around 70% of the time is spent at home, this can have a significant impact on human exposure to NO2. Therefore, although Aveiro has low levels of NO2 outdoors, its population may be exposed to much higher levels of this pollutant than the Porto population, a city with air quality issues, but predominantly using electric cookers. This finding emphasizes the need for the stricter regulation of NG use indoors to protect human health and also suggests a shift in human health protection policies from mere monitoring/control of outdoor air quality to a comprehensive assessment of human exposure, including exposure to indoor air quality.

Pesticide residues and associated health effects in marketed fruits in Saudi Arabia

AimThis study evaluated the pesticide residues in some fruits collected from different markets in Saudi Arabia (SA) and determined potential health risks associated with them. MethodsConcentrations of pesticide residues in 12 types of fruits from local markets in SA from 2020 to 2022 were collected and evaluated. Multiple residue extraction method QuEChERS followed by LC-MS/MS and GC–MS/MS, were used to analyze 161 samples. ResultsOnly 10 out of 161 samples (6.2 %) were free of pesticides. A total of 132 (87.4 %) pesticide residues were below MRLs, with 19 (12 %) of samples exceeding MRLs. Detected pesticide residues belonged to different chemical classes of pesticides including organophosphates, pyrethroids, organochlorines, neonicotinoids and fungicides. Risk assessment of human exposure to pesticides via the intake of the fruit types was performed. Hazard index (HI) for most fruit types were found to be less than 1. Oranges, grapes and pomegranates were the most consumed fruit types (31.6 g/day,15.8 g/day,10.8 g/day) and were contaminated with pesticide residues. Fluopyram, imazalil, chlorpyrifos, finamiphos and indoxacarb had HIs (1.32, 2.76,3.6,3.6,1.5) showed high risk index suggesting risk for systemic toxicity in consumers dependent on the amount of consumption. ConclusionIn summary, high detection rate of pesticide residues was found in different fruits sold in local markets in SA. Regular biomonitoring programs for food crops in SA markets should be enforced, particularly in identified crops with His >1 to increase food safety within the SA community.

Polystyrene nanoplastics accelerate atherosclerosis: Unraveling the impact on smooth muscle cells through KIF15-mediated migration

Microplastics and nanoplastics (MNPs) originating from plastic pollution pose potential threats to cardiovascular health, with prior studies linking MNPs to atherosclerosis. Our earlier research elucidated how nanoplastics enhance macrophages' phagocytic activity, leading to the formation of foam cells and an elevated risk of atherosclerosis. However, the specific influence of MNPs on smooth muscle cells (SMCs) in the context of MNP-induced atherosclerosis remains poorly understood. In this study, ApoE knockout (ApoE-/-) male mice with a high-fat diet were orally exposed to environmentally realistic concentrations of 2.5–250 mg/kg polystyrene nanoplastics (PS-NPs, 50 nm) for consecutive 19 weeks. Cardiovascular toxicity was comprehensively assessed through histopathological, transcriptomic, and proteomic analyses, while mechanisms underlying this toxicity were explored through in vitro studies. Herein, hematoxylin and eosin staining revealed accelerated atherosclerotic plaque development in ApoE-/- mice exposed to PS-NPs. Multi-omics analysis identified kinesin family member 15 (KIF15) as a pivotal target molecule. Both in vitro and in vivo experiments affirmed the specific upregulation of KIF15 in mouse aortic SMCs exposed to PS-NPs. Furthermore, in vitro experiments demonstrated that PS-NPs can promote the migration ability of MOVAS cells. Knockdown of Kif15 revealed its role in reducing MOVAS cell migration, with subsequent exposure to PS-NPs reversing the increased migration ability. This suggests that PS-NPs promote SMC migration by upregulating KIF15, and the migration of SMCs is closely associated with atherosclerosis outcomes. This study significantly advances our understanding of MNP-induced cardiovascular toxicity, providing valuable insights for risk assessment of human MNP exposure.

Source identification and human exposure assessment of organophosphate flame retardants and plasticisers in soil and outdoor dust from Nigerian e-waste dismantling and dumpsites

Electronic waste (e-waste) dismantling and dumpsite processes are major sources of organophosphate flame retardant and plasticiser emissions and may pose potentially adverse effects on environment and human health. In 20 outdoor dust and 49 soil samples collected from four e-waste dismantling and three e-waste dumpsites in two States of Nigeria (Lagos and Ogun), we identified 13 alternative plasticisers (APs), 7 legacy phthalate plasticisers (LPs), and 17 organophosphorus flame retardants (OPFRs) for the first time in African e-waste streams. In the samples from dismantling sites, the range (median) concentrations of ∑13APs, ∑7LPs, and ∑17OPFRs were 11 to 2747 μg/g (144 μg/g), 11 to 396 μg/g (125 μg/g), and 0.2 to 68 μg/g (5.5 μg), in dust respectively and 1.8 to 297 μg/g (55 μg/g), 1.3 to 274 μg/g (48.5 μg/g), and 1.6 to 62 μg/g (1.6 μg/g), in soil respectively. Results for soil samples from e-waste dumpsites were (6.6 to 195 μg/g (23.7 μg/g), 6.0 to 295 μg/g (54.8), and 0.4 to 42.3 μg/g (9.0 μg/g) for ∑13APs, ∑7LPs, and ∑17OPFRs respectively. Overall, concentrations of APs were significantly higher at the dismantling sites (p = 0.005) compared to dumpsites, levels of LPs were higher at dismantling sites but not significant, while OPFR concentrations were significantly higher in dumpsite samples (p = 0.005). Plasticisers were found to be major contributors to pollution at e-waste dismantling sites, while OPFRs were associated with both automobile dismantling and e-waste dumpsite processes. Following particle size fractionation of selected soil samples, higher concentrations of targeted compounds were observed in the smaller mesh (180 μm) soil sieve fraction. For dust, the total median estimated daily intake via ingestion and dermal adsorption (EDIing and EDIderm) ranged from 43 to 74 ng/kg bw/day and 0.4 to 0.7 ng/kg bw/day, respectively. Correspondingly, 4.6 to 45 ng/kg bw/day and 0.015 to 0.57 ng/kg bw/day were the values found for soil, respectively. According to these results, the targeted chemicals do not appear to pose a non-carcinogenic risk to e-waste workers through ingestion or dermal contact of bio-accessible fractions of the chemicals. Human biomonitoring campaigns are recommended in the Nigerian e-waste environment considering the elevated concentration levels found for the majority of targeted compounds and that risk parameters required for exposure assessment were only available for a limited number of compounds.

Wristband Personal Passive Samplers and Suspect Screening Methods Highlight Gender Disparities in Chemical Exposures.

Wristband personal samplers enable human exposure assessments for a diverse range of chemical contaminants and exposure settings with a previously unattainable scale and cost-effectiveness. Paired with nontargeted analyses, wristbands can provide important exposure monitoring data to expand our understanding of the environmental exposome. Here, a custom scripted suspect screening workflow was developed in the R programming language for feature selection and chemical annotations using gas chromatography-high-resolution mass spectrometry data acquired from the analysis of wristband samples collected from five different cohorts. The workflow includes blank subtraction, internal standard normalization, prediction of chemical uses in products, and feature annotation using multiple library search metrics and metadata from PubChem, among other functionalities. The workflow was developed and validated against 104 analytes identified by targeted analytical results in previously published reports of wristbands. A true positive rate of 62 and 48% in a quality control matrix and wristband samples, respectively, was observed for our optimum set of parameters. Feature analysis identified 458 features that were significantly higher on female-worn wristbands and only 21 features that were significantly higher on male-worn wristbands across all cohorts. Tentative identifications suggest that personal care products are a primary driver of the differences observed.

Microplastics in honey from Türkiye: Occurrence, characteristic, human exposure, and risk assessment

In this study, honey samples produced in Türkiye in 2023 were analyzed to assess occurrence of microplastics. The microplastics were physically and chemically characterised by stereomicroscope and FT-IR, respectively. Microplastic exposure by honey consumption was also calculated and risk assessment was done. The mean microplastic concentration was 314±353 (0–1280) particles/kg in 32 honey samples analyzed. The microplastics with four different polymers (EVA, PE, PP, and Nylon–6), two different shapes (fiber and fragment), and six different colors (black, brown, green, red, yellow, and transparent) were detected. The daily microplastic intake by consumption of monofloral and multifloral honey was calculated as 1.20 and 0.85 particles/day, respectively. The mean polymer hazard index and microplastic load index levels for all honey samples analyzed were 16.7±16 and 6.70±1.0, respectively. Result of this study confirmed that honey in Türkiye was contaminated with variety of microplastics. Considering to potential health risks of microplastics and associated chemicals to human health, production process should be improved by producers and urgent strategies and controls should be developed and applied by decision makers to eliminate the intake of microplastics through food.

Human inhalation exposure assessment of the airborne microplastics from indoor deposited dusts during winter in Dhaka, Bangladesh

Microplastic (MP) contamination has become a concern due to its ubiquitous presence. Recent studies have found MPs to be present in multiple human organs. This study was carried out to evaluate the presence and characterize MPs in indoor dust deposition. Deposited dust was collected from fifteen households in Dhaka city. The samples underwent quantification of MPs using stereomicroscopy. Fourier Transform Infrared (FTIR) spectroscopy was performed to understand the polymer composition. MPs of the size group ranging from 50 to 250 μm were the most dominant. The deposition rates varied from 7.52 × 10³ MPs/m2/day to 66.29 × 10³ MPs/m2/day, with the mean deposition rate being 34 × 10³ MPs/m2/day. Notably, the number of occupants and the height of the sampling location above the ground level were found to influence the deposition rates. Various polymers, including polyester (PET), polyethylene (PE), Nylon, and polypropylene (PP), were identified. The estimated mean inhalation exposure was 2986 ± 1035 MPs/kg-BW/day. This work highlights the need for additional research to explore indoor microplastic deposition and its potential effect on human health in the densely inhabited and severely polluted megapolis of Dhaka, Bangladesh.

The level, human exposure, and health risk assessment of acrylamide in chips and breakfast cereals: A study from Türkiye

The aim of this study is to determine the acrylamide levels of corn chips, potato chips and breakfast cereals and to evaluate the acrylamide exposure level resulting from the consumption of these foods in terms of health risks. Firstly, the acrylamide levels of corn chips (n=19), potato chips (n=11), and breakfast cereals (n=20) were determined by liquid chromatography-tandem mass spectrometry. Then, the dietary acrylamide exposure resulting from chips and breakfast cereals consumption was calculated. Finally, dietary acrylamide exposure, target hazard quotient, the lifetime carcinogenic risk, and the margin of exposure approach values were calculated. The mean acrylamide levels of corn chips, potato chips, and breakfast cereals were 317±12, 3578±546, and 138±14 µg/kg, respectively. The mean acrylamide level of all chips was 1513±1876 µg/kg. The mean daily acrylamide exposure from the consumption of corn chips, potato chips, and breakfast cereals was calculated as 0.11±0.10, 1.28±0.58, and 0.08±0.06 µg/kg bw/day, respectively. The target hazard quotient values of acrylamide exposure from the consumption of corn chips, potato chips (except ketchup-flavored potato chips), and breakfast cereals are less than 1. However, the level of acrylamide exposure from the consumption of a total of 13 food samples−2 from corn chips, 10 from potato chips, and 1 from breakfast cereals−reaches alarming levels in terms of carcinogenic health risks. It is required that consumers reduce the frequency and amount of consumption of chips and breakfast cereals, especially potato chips. The results can serve as a guide for reducing exposure to acrylamide through chips and breakfast cereals consumption.

Investigating the release of microplastics from tea bags into tea drinks and human exposure assessment

Investigating the release of microplastics from tea bags into tea drinks and human exposure assessment

Spatial distribution of pesticide use based on crop rotation data in La Plata River basin: a case study from an agricultural region of Uruguay.

The intensive global use of pesticides presents an escalating threat to human health, ecosystems, and water quality. To develop national and local environmental management strategies for mitigating pollution caused by pesticides, it is essential to understand the quantities, timing, and location of their application. This study aims to estimate the spatial distribution of pesticide use in an agricultural region of La Plata River basin in Uruguay. Estimates of pesticide use were made by surveying doses applied to each crop. This information was spatialized through identifying agricultural rotations using remote sensing techniques. The study identified the 60 major agricultural rotations in the region and mapped the use and application amount of the nine most significant active ingredients (glyphosate, 2,4-dichlorophenoxyacetic acid, flumioxazin, S-metolachlor, clethodim, flumetsulam, triflumuron, chlorantraniliprole, and fipronil). The results reveal that glyphosate is the most extensively used pesticide (53.5% of the area) and highest amount of use (> 1.44kg/ha). Moreover, in 19% of the area, at least seven active ingredients are applied in crop rotations. This study marks the initial step in identifying rotations and estimating pesticide applications with high spatial resolution at a regional scale in agricultural regions of La Plata River basin. The results improve the understanding of pesticide spatial distribution based on data obtained from agronomists, technicians, and producers and provide a replicable methodological approach for other geographic and productive contexts. Generating baseline information is key to environmental management and decision making, towards the design of more robust monitoring systems and human exposure assessment.

Microplastics in fish and a bivalve species sampled from freshwater environment and retail outlets, and the assessment of human exposure

The issue of microplastic pollution has emerged as a significant environmental concern in recent times, exerting adverse effects on both aquatic ecosystems and human health. Multiple studies have indicated that the prevalence of microplastics was greater in fish and bivalves obtained from retail outlets (non-farmed) compared to those collected live from freshwater environments. In this study, black clams (Villorita cyprinoides) and fishes (Etroplus suratensis, Etroplus maculatus) were collected from the freshwaters of Periyar River and also from the local retail outlets to analyse the microplastic abundance. Microplastics were significantly higher in numbers from the fish and clams obtained from the retail outlets than the ones collected from the river. Fibres were the dominant morphotype. Polyethylene, polypropylene and polystyrene were majorly obtained. Humans are at risk of consuming approximately 936 microplastics annually from the consumption of two species of fish and 26 microplastics per 100g of clam meat consumed. The presence of microplastics in the species purchased from the retail outlets indicates that there is a possibility for human exposure and this finding raises serious concerns regarding food safety.

Per- and polyfluoroalkyl substances in Chinese commercially available red swamp crayfish (Procambarus clarkii): Implications for human exposure and health risk assessment

The extensive utilization of per- and polyfluoroalkyl substances (PFASs) has led to their pervasive presence in the environment, resulting in contamination of aquatic products. Prolonged exposure to PFASs has been linked to direct hepatic and renal damage, along with the induction of oxidative stress, contributing to a spectrum of chronic ailments. Despite the recent surge in popularity of red swamp crayfish as a culinary delicacy in China, studies addressing PFASs' exposure and associated health risks from their consumption remain scarce. To address this gap, our study investigated the PFASs’ content in 85 paired edible tissue samples sourced from the five primary red swamp crayfish breeding provinces in China. The health risks associated with dietary exposure were also assessed. Our findings revealed widespread detection of PFASs in crayfish samples, with short-chain perfluoroalkyl carboxylic acids (PFCAs) exhibiting the highest concentrations. Notably, the total PFAS concentration in the hepatopancreas (median: 160 ng/g) significantly exceeded that in muscle tissue (5.95 ng/g), as did the concentration of every single substance. The hazard quotient of perfluorohexanesulfonic acid (PFHxS) via consuming crayfish during peak season exceeded 1. In this case, a potential total non-cancer health risk of PFASs, which is mainly from the hepatopancreas and associated with PFHxS, is also observed (hazard index>1). Thus, it is recommended to avoid consuming the hepatopancreas of red swamp crayfish. Greater attention should be paid to governance technology innovation and regulatory measure strengthening for short-chain PFASs.

Bisphenol A-What Do We Know? A Global or Local Approach at the Public Health Risk Level.

BPA has demonstrated enormous multisystem and multi-organ toxicity shown mainly in animal models. Meanwhile, the effects of its exposure in humans still require years of observation, research, and answers to many questions. Even minimal and short-term exposure contributes to disorders or various types of dysfunction. It is released directly or indirectly into the environment at every stage of the product life cycle, demonstrating its ease of penetration into the body. The ubiquity and general prevalence of BPA influenced the main objective of the study, which was to assess the toxicity and health effects of BPA and its derivatives based on the available literature. In addition, the guidelines of various international institutions or regions of the world in terms of its reduction in individual products were checked. Bisphenol A is the most widely known chemical and perhaps even the most studied by virtually all international or national organizations, but nonetheless, it is still controversial. In general, the level of BPA biomonitoring is still too high and poses a potential threat to public health. It is beginning to be widely argued that future toxicity studies should focus on molecular biology and the assessment of human exposure to BPA, as well as its substitutes. The effects of its exposure still require years of observation, extensive research, and answers to many questions. It is necessary to continue to deepen the knowledge and interest of many organizations, companies, and consumers around the world in order to make rational purchases as well as future choices, not only consumer ones.

Inhalable Fungi and Opportunistic Pathogens During Haze and Haze‐Dust Events From Winter to Springtime in One Typical Inland City of Northern China

AbstractFungal aerosols, as significant biocomponents of inhalable particulate matter, encompass a variety of allergens and pathogens. However, comprehensive knowledge regarding their composition, sources, and opportunistic pathogens present in severe air pollution remains limited. In this study, PM2.5 samples were collected from January to March 2018 in a northern Chinese city, during the winter heating and spring sandstorm seasons. The fungal community characteristics within three distinct haze and haze‐dust composite pollution were examined. The concentration of fungal aerosols was found to be significantly higher in dust samples. This was evidenced by a strong positive correlation with Ca2+, temperature, and wind speed (p &lt; 0.05). Human and animal pathogens, such as Candida, were more prevalent in haze samples. Conversely, allergens and plant pathogens, like Alternaria, were found in higher concentration in dust samples. The primary ecological function shifted from being saprophytic to becoming human‐animal pathogenic or plant‐animal pathogenic. This shift was observed from non‐pollution, haze, to haze‐dust composite pollution. The dispersion of fungal aerosols was influenced by factors such as dust events and meteorological conditions, including increased temperature and wind speed. In the spring dust episodes, dust‐related pollutants, such as soil Ca2+ and PM10, accounted for 51.39% of the variation in the fungal community. This research explored the dynamics of fungal communities, potential pathogens, and factors influencing fungal communities in regional air pollution. The insights garnered from this research provide a robust foundation for subsequent human health exposure assessments.

On some computational aspects for electromagnetic-thermal dosimetry of mm waves

This work is on the use of a state-of-the-art hybrid boundary element method/finite element method (BEM/FEM) for electromagnetic (EM) dosimetry and the coupled thermal dosimetry model based on the Pennes’ heat transfer equation (PHE) for biological tissue solved by means of FEM. The distribution of the induced electric field obtained in both homogeneous and non-homogeneous human head models using EM model is used as a distributed heat source in the piecewise homogeneous human head thermal dosimetry model. As the penetration depth is inversely proportional to the frequency of incident EM wave, we consider the heating depth in several human head models, to illuminate whether homogeneous models in the EM part of the model are pertinent in the thermal dosimetry part. If confirmed, the results could be found useful in standardisation efforts related to the assessment of human exposure to EM fields in the high frequency range.