Simultaneous detection of multiple mycotoxins in Radix Dipsaci and estimation of exposure risk for consumers.

Like many traditional Chinese herbal medicines, preparations from Radix Dipsaci are at risk of contamination by harmful mycotoxins; however, there have been no reports of actual contamination. In this study, we developed an analytical method to simultaneously detect eight mycotoxins in Radix Dipsaci and estimate the exposure risk for consumers. We have developed an analytical method utilizing ultra-high performance liquid chromatography and tandem mass spectrometry to accurately determine the levels of AFB1, AFB2, AFG1, AFG2, OTA, ZEN, T-2 and ST mycotoxins in 45 batches of Radix Dipsaci sourced from major medicinal herb markets across five regions in China. We also analyzed migration of mycotoxins from the raw herbs into water decoction. Based on these results and data on human consumption of the herbal medicine, we estimated risk of exposure and acceptable exposure limits to mycotoxins in the Radix Dipsaci using the "margin of exposure (MOE)" method. Of the 45 batches of Radix Dipsaci, 48.89% contained at least one of the eight mycotoxins, 24.44% contained one, 17.78% contained two and 6.67% contained three. The most frequent mycotoxins were aflatoxin B1, present in 35.56% of batches (at 0.25-34.84 µg/kg); aflatoxin G1, 15.56% (1.99-44.05 µg/kg); and ochratoxin A, 22.22% (16.11-143.38 µg/kg). These three mycotoxins transferred from the raw herb into water decoction at respective rates of 20.20%, 29.14%, and 24.80%. The 95th percentile values of the MOE risk factors for health effects of AFB1 were below 10,000 at high doses but above 10,000 at low doses of Radix Dipsaci long-term treatment. With the reduction in duration of exposure years, the MOE values of AFB1 and AFG1 gradually reverted to within the acceptable range. The mean, 50th, and 95th percentile values of the MOE risk factors for health effects of OTA exceeded 10,000 regardless of whether consumers received a low or high dose of Radix Dipsaci treatment for durations ranging from 1 to lifetime. Based on this exposure and a typical human diet, we have estimated the respective 20-year exposure limits for Radix Dipsaci to be 5.821 µg/kg, 4.035 µg/kg, and 56.073 µg/kg for the three mycotoxins under consideration. Contamination with multiple mycotoxins is frequently observed in Radix Dipsaci, and the three most prevalent contaminants have been found to leach into water decoctions, thereby posing a potential health hazard for individuals consuming this herbal preparation. This work highlights the need to monitor herbal medicines for mycotoxin contamination in order to protect consumers.

Mitigating aerosol-induced respiratory infections in home quarantine: The role of door dynamics and ventilation in residential design.

Respiratory infectious diseases, notably recurring waves of COVID-19 during autumn and winter, have significantly impacted global health and strained public health systems. Home isolation has emerged as a crucial and economical strategy to mitigate these impacts. This study investigates aerosol transmission and infection risks in home isolation environments using the Lattice Boltzmann Method with Large Eddy Simulation (LBM-LES). We focused on the impact of door operations and various natural ventilation rates on aerosol transmission and exposure risk in adjacent rooms. Our findings reveal that, without ventilation, aerosol leakage through door gaps poses a minimal infection risk to adjacent rooms, with an average probability of less than 2 × 10-5. However, with adequate ventilation, the infection risk for individuals in adjacent rooms for over 3 h can reach 60 %-70 %. Brief door movements have limited impact on infection risk (p ≤ 0.05, d ≤ 0.20), with aerosol leakage mainly occurring through door gaps rather than door movements. To reduce cross-infection during home isolation, we recommend avoiding prolonged stays near downwind walls facing the door. This research provides insights into aerosol dynamics in home isolation scenarios, offering theoretical guidance for designing safe isolation spaces and practical advice for healthy family members to minimize infection risk.

Method development, multi-residue determination, and dietary exposure risk assessment of plant growth regulators in homologous materials of medicine and food.

Residues of plant growth regulators (PGRs) in homologous materials of medicine and food threaten public health. This study aimed to develop a rapid, sensitive, and high-throughput method for simultaneously determining 16 PGR residues in homologous materials of medicine and food. Furthermore, the established method was applied to actual samples to assess the potential exposure risk of multi-PGR residues. A modified high-throughput quick, easy, cheap, effective, rugged, and safe (QuEChERS) method coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated. The extraction solvent, type of extraction method, and subsequent purification techniques were investigated to achieve a better analysis of the target. Risk assessment was based on chronic dietary risk assessment. Ultrasonic extraction with 1% formic acid-acetonitrile was employed, and MgSO4 + NaAc was selected as the clean-up sorbent. The 16 PGRs showed a good linear relationship in the range of 1 ~ 200 µg/L (r ≥ 0.9960), with detection limits ranging from 0.3 to approximately 3 µg/kg. The recovery rate ranged from 65 to 109%, with RSD from 0.01 to 10% (n = 6). The total detection rate of 16 PGRs in the samples was 87%. The risk assessment indicated that the multi-residues of PGRs in homologous materials of medicine and food would not pose a potential risk to human health. This work provides a valuable reference for the monitoring of multiple PGRs. It has also improved our understanding of the possible exposure risk of PGR residues in homologous materials of medicine and food.

A Meta-Analysis of Mercury Biomagnification in Freshwater Predatory Invertebrates: Community Diversity and Dietary Exposure Drive Variability.

Accurate estimates of methylmercury (MeHg) exposure are valuable to actionably assess risk and protect wildlife and human health. MeHg trophic transfer is a critical driver of risk: MeHg is generally biomagnified by a factor of 8.3 ± 7.5 from one trophic level to the next, averaged across freshwater communities (mean ± standard deviation). This variability can produce disparate risks even where basal MeHg concentrations are similar. Taxonomy may be one driver of this variability: physiologically diverse groups, like vertebrates and invertebrates, may assimilate MeHg differently. To determine whether taxonomy affects trophic transfer efficiency, we conducted a meta-analysis characterizing predatory invertebrate MeHg biomagnification. Our analyses estimated that freshwater predatory invertebrates biomagnify MeHg by factors of 2.1 ± 0.2 to 4.3 ± 0.3, with a 98.9 ± 0.4% posterior probability that factors are below 5 (mean ± standard error). When vertebrates or primary producers were included, a site's trophic magnification factor was 18.6 ± 6.2 to 54.1 ± 7.7% higher than estimates for invertebrates alone. Biomagnification was inversely correlated to prey MeHg concentration and varied among systematic and functional groups. These data suggest that predatory invertebrates biomagnify MeHg less efficiently than vertebrates and that a community's diversity and structure determine its biomagnification efficiency. Incorporating organismal variation in trophic transfer estimates may improve the assessment, communication, and management of MeHg risk.

A review of airborne micro- and nano-plastics: Sampling methods, analytical techniques, and exposure risks.

Atmospheric Micro- and nano-plastics (MNPs) can be easily inhaled and ingested by humans and have become a global health concern. With the development of instruments and techniques, an increasing number of sampling and analytical methods have been applied to study airborne MNPs. Active samplers and passive collectors are used to collect suspended aerosols and atmospheric depositions. Microscopes and scanning electron microscopy (SEM) have been used to physically identify the MNPs, while Fourier transform infrared (FTIR), Raman spectroscopy, and Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) are used to identify the polymer compositions of the MNPs. However, the diversity of methods and strategies has greatly limited our ability to compare results and assess exposure risks. In this review, we extracted data from PubMed, Embase, and Scopus from 2018 to 2024 that reported sampling methods, analytical techniques, and abundance/deposition of airborne MNPs. Through a systematic review of the included 140 articles, we emphasized the advantages and limitations of different methods for collecting and analyzing airborne MNPs. In addition, we provided an in-depth analysis of the performance of specific methods across different airborne environments. Furthermore, the current knowledge regarding the abundance, deposition, exposure risks of airborne MNPs, and exposure risk assessment models has been discussed. Finally, we provide concrete recommendations for standardization of methods. This review identified knowledge gaps and recommended future research directions for exposure assessment of airborne MNPs.

Pesticide exposure and spontaneous abortion risk: A comprehensive systematic review and meta-analysis.

BACKGROUNDS AND AIM: Exposure to pesticides has been proposed as a potential contributor to adverse pregnancy outcomes, possibly through the induction of inflammation, oxidative stress, and disruption of endocrine functions. Nevertheless, the definitive link between prenatal pesticide exposure and the risk of Spontaneous Abortion (SAB) remains uncertain. The objective of this systematic review is to explore and analyze the existing evidence regarding the link between pesticide exposure and the risk of SAB. METHODS: A comprehensive systematic literature search was carried out on PubMed, Web of Science, and Scopus from their inception until February 2024 to identify relevant studies exploring the potential link between pesticide exposure and SAB. The frequency of SAB events and the total number of patients in each group were used to calculate the Relative Risk (RR) using the Mantel-Haenszel random-effects model. Heterogeneity among the studies was evaluated by visually inspecting the forest plot and performing the Chi-square test and I2 tests. We also used RevMan version 5.4 for Windows for the analysis. We also used the NIH tool to assess the quality of the included studies. RESULTS: The initial database search yielded 2121 results, with 1525 articles remaining after removing duplicates. After screening, 29 articles were eligible for full-text review, and 18 studies (Four case-control, eleven cohorts, three cross-sectional) were included in the meta-analysis, comprising 439,097 participants. All included studies evaluated the primary outcome, SAB. Most of the included studies were cross-sectional in design, and pesticide exposure was primarily assessed through questionnaires administered to patients. We found that most of our observational studies, precisely 12 out of the total, were deemed fair quality. Four studies were rated poor quality, while only two received a good quality rating. The analysis demonstrated a significant 41 % increase in SAB risk among pregnant women exposed to pesticides compared to pregnant women without exposure to pesticides (RR= 1.41, 95 % CI; [1.10, 1.80], P= 0.006). CONCLUSION: Our systematic review and meta-analysis revealed a significant 41 % increase in the risk of SAB among pregnant women exposed to pesticides. However, it is essential to acknowledge the limitations of the current evidence: potential publication bias and the inability to establish causality. Moving forward, future research should focus on longitudinal studies, mechanistic insights, and risk reduction strategies. In summary, our findings underscore the urgency of public health measures to protect maternal and fetal health in pesticide-exposed areas. Rigorous research and preventive strategies are crucial to mitigate adverse outcomes.

Chronic bisphenol A induced neurotoxicity: Exposure risk, molecular fate within carp and its potential phytoremediation.

Bisphenol A (BPA) is an endocrine-disrupting toxicant commonly used in the plastics industry, as a result, it is present in large quantities in the environment. Therefore, current study was designed to assess BPA induced neurotoxicity and molecular fate within common carp (Cyprinus carpio), largely used edible fish. Following 6 weeks exposure to BPA 1/5th of 96 h LC50 (1.31 mg/L), brain exhibited oxidative damage, which was evidenced by compromised antioxidant system (CAT, SOD, GSH) and increased level of biomacromolecule peroxidation (MDA and 8-OHDG). Functional damage to the brain observed in the form of blood-brain barrier disruption (decreased tight junction gene expression) and nerve conduction impairment (reduced acetylcholinesterase activity). Mechanistically, apoptotic cell death indicated by characteristic alteration in key biomarkers (bcl-2, caspase, and p53-related gene family). Whereas, coadministration of powdered PP (pomegranate peel) (8 %) with BPA effectively mitigated the BPA toxicity, as evidenced by the restoration of the above-mentioned bioindicators. Thereby, BPA-induced neurotoxicity could be potentially detoxified by applying PP dietary enrichment.

Synergistic PM2.5 and O3 control to address the emerging global PM2.5-O3 compound pollution challenges.

In recent years, the issue of PM2.5-O3 compound pollution has become a significant global environmental concern. This study examines the spatial and temporal patterns of global PM2.5-O3 compound pollution and exposure risks, firstly at the global and urban scale, using spatial statistical regression, exposure risk assessment, and trend analyses based on the datasets of daily PM2.5 and surface O3 concentrations monitored in 120 cities around the world from 2019 to 2022. Additionally, on the basis of the common emission sources, spatial heterogeneity, interacting chemical mechanisms, and synergistic exposure risk levels between PM2.5 and O3 pollution, we proposed a synergistic PM2.5-O3 control framework for the joint control of PM2.5 and O3. The results indicated that: (1) Nearly 50% of cities worldwide were affected by PM2.5-O3 compound pollution, with China, South Korea, Japan, and India being the global hotspots for PM2.5-O3 compound pollution; (2) Cities with PM2.5-O3 compound pollution have exposure risk levels dominated by ST + ST (Stabilization) and ST + HR (High Risk). Exposure risk levels of compound pollution in developing countries are significantly higher than those in developed countries, with unequal exposure characteristics; (3) The selected cities showed significant positive spatial correlations between PM2.5 and O3 concentrations, which were consistent with the spatial distribution of the precursors NOx and VOCs; (4) During the study period, 52.5% of cities worldwide achieved synergistic reductions in annual average PM2.5 and O3 concentrations. The average PM2.5 concentration in these cities decreased by 13.97%, while the average O3 concentration decreased by 19.18%. This new solution offers the opportunity to construct intelligent and healthy cities in the upcoming low-carbon transition.

Occurrence and human exposure risk of antibiotic resistance genes in tillage soils of dryland regions: A case study of northern Ningxia Plain, China.

Agricultural soils are important source and sink of antibiotic resistance genes (ARGs). However, little is known about the fate of ARGs in dryland soils, while its human exposure risks were seriously overlooked. Taking the northern Ningxia Plain as a case, this study explored the occurrence of ARGs and its relationship with mobile genetic elements (MGEs), pathogens, and environmental factors. Furthermore, the concentrations of airborne ARGs by soil wind erosion and the human exposure doses of soil ARGs were evaluated. The results showed the abundances of different regions ranged from 4.0 × 105 to 1.6 × 106 copies/g. Soil ARGs are driven by MGEs, but multiply impacted by soil properties, nutrition, and bacterial community. Vibrio metschnikovii, Acinetobacter schindleri, and Serratia marcescens are potential pathogenic hosts for ARGs. Further exploration revealed the concentration of ARGs loaded in dust by soil wind erosion reached more than 105 copies/m3, which were even higher than those found in sewage treatment plants and hospitals. Skin contact is the primary route of ARGs exposure, with a maximum dose of 24071.33 copies/kg/d, which is largely attributed to ARGs loaded in dust. This study bridged the gap on ARGs in dryland soils, and provided reference for human exposure risk assessment of soil ARGs.

Distribution, bioaccumulation and human exposure risk of bisphenol analogues, bisphenol A diglycidyl ether and its derivatives in the Dongjiang River basin, south China.

Bisphenols, bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE) are commonly used as raw materials or additives in the production of several industrial and consumer products. However, information regarding the occurrence and distribution of these industrial chemicals in freshwater ecosystem is limited. In this study, four bisphenols, six BADGEs, and three BFDGEs were determined in abiotic and biotic samples collected from the Dongjiang River basin in southern China. Among the four bisphenols, BPA was widely present in all samples analyzed including surface water (median: 1.81 ng/L), sediment (3.1 ng/g dw), aquatic plants (3.69 ng/g dw), algae (7.57 ng/g dw), zooplankton (6.17 ng/g dw), and fish muscle (5.28 ng/g dw). Among the nine BADGEs and BFDGEs analyzed, BADGE, BADGE•H2O, BADGE·HCl·H2O and BADGE•2H2O was found in all sample types. Although the median concentration of BADGE•2H2O in surface water was below LOQ, this compound was found at median concentrations of 2.61, 3.59, 1.03, 1.69, and 49.8 ng/g dw in sediment, plants, algae, zooplankton, and fish muscle, respectively. Significant positive linear correlations were found among logarithmic transformed concentrations of BPA, BADGE, BADGE•H2O, BADGE•HCl•H2O, and BADGE•2H2O in sediment. The bioconcentration factor (logBCF) values of BADGE, BADGE•H2O, BADGE•HCl, BADGE•HCl•H2O, BADGE•2H2O, and BADGE•2HCl in fish, plants, algae, and zooplankton were > 3.3 L/kg (wet weight), indicating that these chemicals possess moderate bioaccumulation potential. The estimated daily total intake of bisphenols and BADGEs through fish consumption was 75.1 ng/kg bw/day for urban adult residents. The study provides baseline information on the occurrence of bisphenols, BADGEs, and BFDGEs in a freshwater ecosystem.

Widespread occurrence of glyphosate and aminomethylphosphonic acid in indoor dust from urban homes across the United States and its contribution to human exposure.

Glyphosate is the most widely used herbicide worldwide, with concerns over human exposure and potential health risks. Nevertheless, little is known about the sources of human exposure to glyphosate and its degradation product, aminomethylphosphonic acid (AMPA). In this study, we measured glyphosate and AMPA in 99 indoor dust samples collected from urban homes in sixteen states in the USA. Glyphosate and AMPA were detected in all samples at geometric mean (GM) concentrations of 193 and 30.8 ng/g, respectively. We found a strong and significant positive correlation between glyphosate and AMPA concentrations (r = 0.70, p < 0.01), indicating that the latter mainly originated from glyphosate. The concentrations of glyphosate (r = 0.40, p < 0.01) and AMPA (r = 0.33, p < 0.01) in indoor dust were significantly correlated with the county-wide agricultural usage of this herbicide. Human exposure to glyphosate and AMPA through dust ingestion were in the ranges of 0.05-0.85 and 0.01-0.14 ng/kg body weight (BW)/day, respectively, for various age groups, which were more than two orders of magnitude below the acceptable daily intake for glyphosate (500 µg/kg BW/day). Further studies are needed to identify the sources and health outcomes of human exposure to glyphosate.

A review of liquid crystal monomers (LCMs) as emerging contaminants: Environmental occurrences, emissions, exposure routes and toxicity.

The widespread occurrence of liquid crystal monomers (LCMs) in the environment has raised concerns about their persistence, bioaccumulation, and toxicity (PBT). Here we review the lifecycle of environmental LCMs, focusing on their occurrences, emission sources, human exposure routes, and toxicity. Industrial emissions from Liquid Crystal Display (LCD) manufacturing and e-waste recycling are the primary point sources of LCMs. In addition, emissions from LCD products, air conditioning units, wastewater treatment plants, and landfills contribute to environmental occurrence of LCMs as secondary sources. Dietary routes were identified as the primary exposure pathways to humans. E-waste dismantling workers and infants/children are vulnerable populations to LCMs exposure. Exposure to LCMs has been shown to potentially induce oxidative stress, metabolic disorders, and endocrine disruption. Accumulation of LCMs in the brain and liver tissues of exposed animals highlights the need for toxicokinetic studies.

Exposure Practices to Animal-Origin Influenza A Virus at the Animal-Human Interface in Poultry and Swine Backyard Farms.

AIM: Backyard production systems (BPS) represent an interface of contact between people, domestic and wild animals. Studies conducted in Chile during the last decade have provided extensive evidence of influenza A virus (IAV) circulation in backyard poultry and swine. The aim of this study was to investigate exposure practices of humans to animal-origin IAV within backyards. METHODS AND RESULTS: Backyard farmers and household members of a total of 101 BPS in the proximity of wetlands located throughout Chile were interviewed between 2021 and 2022. Data were collected on the nature of human-animal contacts through participation in productive activities conducted within backyards, which was used to estimate participants' exposure risk to animal-origin IAV. Additionally, RT-qPCR and serologic IAV active surveillance was carried out in backyard animals. Multilinear regression was used to identify factors associated with exposure risk. Overall, IAV prevalence was 10.1% (95% CI: 4.7%-15.5%) and seroprevalence was 43.5% (95% CI: 29.7%-54.2%), both at the BPS level. Of 180 interviewees, 86% reported participating regularly in poultry or swine exposure activities within the backyard. A greater participation of male participants was observed when evaluating swine exposure activities, while female participation was greater for some activities related to poultry handling. Handwashing was a very extended hygiene practice; however, the use of personal protective equipment was uncommon. Different factors related to participants, households and backyards were associated with an increased exposure risk of participants to animal-origin IAV: (i) older age, (ii) less years of education, (iii) no off-farm work, (iv) greater backyard production value and (v) greater household consumption of backyard products. CONCLUSION: These results indicate the circulation of IAV in BPS and the frequent human-animal contact at this interface, highlighting the need for awareness campaigns and educational programmes aimed at backyard farmers on prevention and biosecurity measures in the management of backyard animals.

Enhanced health risk of soil heavy metal exposure following an extreme rainstorm under climate change.

Widespread concerns raised in changes in the health risk of soil heavy metals exposure due to extreme rainstorm under climate change. However, the impacts of extreme rainstorm on human exposure risk and the underlying mechanisms are still unclear. In this study, soil properties, speciation distribution and bioaccessibility of Ni, Cu, Zn, Cd and Pb in soil samples, which were collected before and after extreme rainstorm, were measured, subsequently the soil oral exposure risk of heavy metals was assessed based on bioaccessibility. Results indicate that extreme rainstorm can significantly enhance the accumulated non-carcinogenic and carcinogenic exposure risk by 10.1-188.3 %, with lowland soil posing 1.3-1.7 times higher risk than highland soil. The increase in exposure risk varies among elements in highland and lowland soil. Specifically, the exposure risk for Cd and Pb increased by 2.5-9.7 times, whereas that for Cu decreased by 43.2 % - 60.6 %. The risk of Zn and Ni exposure exhibits complex trends, with an increase of 37.2 %-104.8 % in lowland soil but a decrease of 9.4 %-46.5 % in highland soil. Bioaccessibility variations are the primary risk factors for soil heavy metal exposure during extreme rainstorms, not total concentration. Mechanistically, the extreme rainstorm directly increases soil moisture content and reduce organic matter concentration, leading to an increment in the proportion of bio-utilization speciation and decrement in the speciation bounding to Fe/Mn oxides of soil heavy metals. Furthermore, the bioaccessibility of soil heavy metal positively correlates with their bio-utilization speciation and negatively correlates with their speciation bounding to Fe/Mn oxides, which ultimately increasing exposure risk. Our study suggests the necessity that attentions should be paid to the enhanced health risk associated with soil heavy metal exposure following extreme rainstorm, particularly for population residing in lowland areas.

Seroprevalence of hantavirus infection in non-epidemic settings over four decades: a systematic review and meta-analysis.

INTRODUCTION: Hantavirus infection is a zoonotic disease from rodents to humans, necessitating seroprevalence assessment for disease burden clarification and control measure implementation. This study aimed to estimate global hantaviruses seroprevalence, examining variations by regions, populations or settings. METHODS: A comprehensive database search identified studies on human hantaviruses seroprevalence using IgG detection until january 2024. A random-effects meta-analysis estimated pooled seroprevalence, with subgroup analyses for geographical region, population, setting or occupation. RESULTS: Out of 3,382 abstracts reviewed, 110 studies were selected, comprising 81,815 observations and 3207 events. The global seroprevalence was calculated at 2.93% (2.34%-3.67%). In terms of geographical distribution, our analysis encompassed 61 studies from the Americas, where the seroprevalence was estimated at 2.43% (95% CI: 1.71%-3.46%), 33 studies from Europe indicating a seroprevalence of 2.98% (95% CI: 2.19%-4.06%), 10 studies from Asia revealing a seroprevalence of 6.84% (95% CI: 3.64%-12.50%), and 6 studies from Africa demonstrating a seroprevalence of 2.21% (95% CI: 1.82%-2.71%). Subgroup analysis underscored varying seroprevalence rates across different populations, settings, and occupations, highlighting the necessity for targeted interventions and preventive measures. CONCLUSION: The analysis reveals a moderate global hantaviruses seroprevalence, emphasizing the viral family's complex transmission dynamics influenced by exposure and geographical factors. This highlights the need for targeted prevention and control strategies.

Source apportionment of particle-bound polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs), and their associated long-term health risks in a major European city.

Many studies have drawn attention to the associations of oxygenated polycyclic aromatic hydrocarbons (OPAHs) with harmful health effects, advocating for their systematic monitoring alongside simple PAHs to better understand the aerosol carcinogenic potential in urban areas. To address this need, this study conducted an extensive PM2.5 sampling campaign in Athens, Greece, at the Thissio Supersite of the National Observatory of Athens, from December 2018 to July 2021, aiming to characterize the levels and variability of polycyclic aromatic compounds (PACs), perform source apportionment, and assess health risk. Cumulative OPAH concentrations (Σ-OPAHs) were in the same range as Σ-PAHs (annual average 4.2 and 5.6 ng m-3, respectively). They exhibited a common seasonal profile with enhanced levels during the heating seasons, primarily attributed to residential wood burning (RWB). The episodic impact of biomass burning was also observed during a peri-urban wildfire event in May 2021, when PAH and OPAH concentrations increased by a factor of three compared to the monthly average. The study period also included the winter 2020-2021 COVID-19 lockdown, during which PAH and OPAH levels decreased by >50 % compared to past winters. Positive matrix factorization (PMF) source apportionment, based on a carbonaceous aerosol speciation dataset, identified PAC sources related to RWB, local traffic (gasoline vehicles) and urban traffic (including diesel emissions), as well as an impact of regional organic aerosol. Despite its seasonal character, RWB accounted for nearly half of Σ-PAH and over two-thirds of Σ-OPAH concentrations. Using the estimated source profiles and contributions, the source-specific carcinogenic potency of the studied PACs was calculated, revealing that almost 50 % was related to RWB. These findings underscore the urgent need to regulate domestic biomass burning at a European level, which can provide concrete benefits for improving urban air quality, towards the new stricter EU standards, and reducing long-term health effects.

Frequency of SARS-CoV-2 Infections among Healthcare Workers in Germany: 3-Year Follow-Up Study.

The emergence of SARS-CoV-2 in 2019 led to a global pandemic with a significant impact on healthcare systems. Healthcare workers were particularly vulnerable due to frequent contact with COVID-19 patients. Despite vaccination, they remained at higher risk as the vaccines provided limited protection against infection with viral variants, like Delta or Omicron BA.1 and BA.5. Three years after the onset of the pandemic, we evaluated SARS-CoV-2 infection frequencies among healthcare workers with varying levels of patient contact: high-risk (frequent COVID-19 patient contact), intermediate-risk (non-COVID-19 patient contact), and low-risk (no patient contact). We assessed their cellular and humoral immune responses based on their vaccination status and number of prior infections. SARS-CoV-2-specific antibodies were measured by immunoglobulin ELISA, and neutralizing antibody titers were determined against the viral variants D614G, Delta, and Omicron BA.1 and BA.5. Cellular immune responses were analyzed using an interferon-γ ELISpot. Notably, three years into the pandemic, healthcare workers in daily contact with COVID-19 patients did not have higher infection rates compared to healthcare workers with non-COVID-19 patient contact or no patient contact. Immune responses were similar across all groups, highlighting the effectiveness of vaccination and current hygiene standards in preventing virus transmission from patients to staff.

Epidemic exposure risk assessment in digital contact tracing: A fuzzy logic approach.

Background: Bluetooth low energy (BLE)-based contact-tracing applications were widely used during the COVID-19 pandemic. However, the use of only the received signal strength feature for proximity calculations may not be adaptable to different virus variants or scalable for other potential epidemic diseases. Objective: This study presents a novel framework in regard to evaluating and classifying personal exposure risk that considers both contact features, which include distance and length of contact, and environment features, which include crowd size and the number of recently infected cases in the environment. The framework utilizes a fuzzy expert system that is adaptable to different virus variants. Methods: The proposed method was tested on two viruses with different close contact features, which used four membership functions and 256 fuzzy rule sets. Results: The proposed framework classified personal exposure risks into four classes, which include low, medium, high, and too high risk. The empirical results showed that the fuzzy logic-based approach reduced the number of false positive cases and demonstrated better accuracy and precision than the current BLE-only approaches. Conclusions: The proposed framework provides a more practical and adaptable method in regard to assessing exposure risks in real-world scenarios. It has the potential to be scalable and adaptable to different virus variants and other potential epidemic diseases by considering both contact and environment features. These findings may be useful in order to develop more effective digital contact-tracing applications and policies.

Comparative analysis of bioaerosol emissions: Seasonal dynamics and exposure risks in hospital vs. municipal wastewater treatment systems.

Hospital wastewater is known to contain various pathogenic microorganisms and harmful substances. During the hospital wastewater treatment process, the bioaerosols released may encapsulate these pathogens, leading to human infection. This study undertook an investigation to compare the dispersion characteristics and seasonal variations of bioaerosols from hospital and municipal sewage. The results indicated that the airborne bacterial concentration from hospital sewage (119 ± 118 CFU/m3) was higher than municipal sewage (46 ± 19 CFU/m3), with the highest concentration observed in summer. The dominant bacterial genera present in bioaerosols from both sewages were alike, with the proportions varied by sewage types and the structure mainly influenced by seasonal factors. Bacteroides, Escherichia-Shigella and Streptococcus were identified as the most prevalent pathogenic genera in spring, summer and winter bioaerosols, respectively, while Pseudomonas and Acinetobacter were abundant in autumn. Although the non-carcinogenic risk associated with bioaerosols was low (<1), the presence of pathogenic species and their potential synergistic interactions elevated the overall exposure risk. The diffusion modeling results demonstrated that bioaerosol emissions from the surface of hospital sewage can reach up to 10570 CFU/m3 in summer and can spread more than 300 m downwind. The potential pathogenicity of bioaerosols was also highest in summer, which may pose a health hazard to populations located downwind. Therefore, the management and control of bioaerosols from sewage should be strengthened, especially in summer.

Assessment of Global Antibiotic Exposure Risk for Crops: Incorporating Soil Adsorption via Machine Learning.

The overuse and misuse of antibiotics could significantly increase their accumulation in soils. Consequently, antibiotics possibly enter food chain through crop uptake, posing a threat to global food security. Assessing the exposure risks of antibiotics for crops is crucial for addressing this global issue. In this study, we assessed global antibiotic exposure risk for crops, incorporating a machine learning adsorption model based on 4893 data sets from nine antibiotics. The optimized machine learning adsorption model, using the eXtreme Gradient Boosting algorithm and the class-specific modeling strategy, demonstrated relatively good performance. Notably, we introduced unsaturated soil conditions and considered spatiotemporal variations in soil moisture and temperature for the first time in such a risk assessment. Global distributions of antibiotic exposure risk for crops were predicted for March, June, September, and December. The results indicate that soil moisture significantly influences the exposure risk assessment. Relatively high exposure risk for crops was observed during months with colder local temperatures: generally June for the Southern Hemisphere and December for the Northern Hemisphere. The resulting map highlights high-risk agricultural regions, including southern Canada, western Russia, and southern Australia.