Evaluation Of Health Risks Research Articles

Dietary Exposure and Health Risk of the Emerging Contaminant Fluorinated Liquid-Crystal Monomers.

Fluorinated liquid-crystal monomers (FLCMs) widely used in liquid crystal displays are considered to be a new generation of persistent, bioaccumulative, and toxic contaminants. They have been widely detected in the environment. However, little is known about their occurrence in food and human dietary exposure until now. Herein, we provided an evaluation of dietary exposure and health risks of FLCMs in the Chinese adult population based on the fifth and sixth total diet studies (TDSs). The detection frequencies of FLCMs in the two surveys were 90.5 and 99.5%, with concentrations ranging from not detected ∼72.6 μg/kg wet weight (ww) and ND ∼74.7 μg/kg ww, respectively. All TDS samples contained the multiresidue of FLCMs. The mean estimated daily intakes (EDIs) of FLCMs were 172.86 and 163.10 ng/kg bw/day in the fifth and sixth TDS, respectively. Meats, vegetables, and cereals contributed the most to the EDI of FLCMs. According to the threshold of toxicological concern (TTC) method, the EDIs of 1-fluoro-4-[2-(4-propylphenyl)ethynyl]benzene (4.56 and 3.26 ng/kg bw/day) and 2-fluoro-4-[4'-propyl-1,1'-bi(cyclohexyl)-4-yl]phenyl trifluoromethyl ether (3.12 and 3.28 ng/kg bw/day) were above their TTC value (2.5 ng/kg bw/day), suggesting their potential health risk. This is the first comprehensive national dietary exposure assessment of FLCMs.

Evaluation and Management of Health and Safety Risks of Chlorine Gas in Transportation Routes

Background: More than 90% of goods movement in Iran is done by road transport. A significant part of these materials is dangerous goods. Considering that chlorine gas is considered a toxic and oxidizing substance, predicting the way of release and mortality due to accidental leakage of chlorine gas can be a crucial tool in adopting preventive strategies. This study aims to evaluate the safety of chlorine gas transportation and analyze the consequences of its release. Materials and Methods: This cross-sectional-analytical study was conducted in 2020 in Tehran. The transportation risk rating index was used to measure and evaluate the quantitative risk of transportation of hazardous materials. PHAST software was used to determine the consequence of possible accident scenarios on the transportation route. In the final stage, according to the amount of traffic, the time and manner of response to emergencies by the fire and emergency organization were simulated using Pathfinder software. Results: In this evaluation, the chlorine risk rating was calculated as 192. The worst possible scenario was a catastrophic rupture of chlorine in the second half of 2021. As a result of the accident, up to a radius of 1800 m from the center of the leak, the dangerous concentration is equal to 20 ppm, that is, equal to the ERPG3 limit. The simulation results showed that the release of poisonous chlorine gas leads to the death of 10% of people up to a radius of 192 m around the scenario. Conclusion: In the scenario of the sudden release of chlorine, in which people need to escape and move away from the accident site, it was found that it takes more than 24 minutes to leave the ERPG-3 area. Considering that the assumed average speed of 1.15 m/s is the average speed of people and naturally the speed of sensitive people is much lower in the conditions of an accident, it can be concluded that in the scenario of a sudden leak, a significant part of the people involved in the accident may suffer severe and irreparable damage.

Evaluation of Health Risk Due to Exposure to Radiation in Some Hospitals in Rivers State

An external background ionization radiation was carried out in Our Lady Health of the sick hospital, Colworth Medical and Olive Tree Medical Diagnostics Port Harcourt. The background radiation reading was taken using the radiation alert meter (Digilert 200). The estimated value for the excess lifetime cancer risk from the three hospitals are lower than the world average, also the annual effective dose equivalent from Our Lady Health of the sick hospital, Colworth Medical Centre and Olive three medical center are lower than the world accepted value. The average absorbed dose rates are higher than the world accepted value which is 84nGy/h. the average exposure rate from the three hospitals is lower than the world accepted value which is 0.013mR/h. the absorbed dose rate exceeded the safe limit for the general public.

Extensive Cryptic Diversity and Ecological Associations Uncovered among Mexican and Global Collections of Naegleria and Vermamoeba Species by 18S Ribosomal DNA, Internal Transcribed Spacer, and Cytochrome Oxidase Subunit I Sequence Analysis.

Free-living amoebae (FLA) are phagocytic protists that play crucial roles in microbial communities as significant microbial grazers. However, our current knowledge of their diversity, ecology, and population genetic structures is marginal due to the shallow and biased sampling of ecosystems and the use of few, poorly resolving molecular markers. Thirty-two FLA were isolated from soil and water samples collected across representative ecosystems of the State of Morelos in Central Mexico, including the drinking water distribution system (DWDS) from the state capital. We classified our isolates as members of Acanthamoeba, Vermamoeba, Naegleria, and Tetramitus by 18S ribosomal DNA (rDNA) sequencing. Vermamoeba isolates were recovered exclusively from the DWDS samples. In contrast, Naegleria strains displayed a broad distribution in soil and water samples across the natural ecosystems. We used a combination of phylogenetic and population genetic analyses of internal transcribed spacer (ITS) and cytochrome oxidase subunit I (COI) sequences from our isolates and a comprehensive set of reference sequences to analyze the currently known diversity of Naegleria spp. Significant associations were uncovered between the most prevalent lineages of Naegleria and Vermamoeba and broad ecological and geographical variables at regional and global levels. The population structure and cryptic diversity within the Naegleria galeacystis-Naegleria americana and Vermamoeba vermiformis species complexes were thoroughly analyzed. Our results prove that the genus Vermamoeba, which was previously thought to consist of only one species, actually encompasses at least seven widely distributed species, as indicated by consistent evidence from Bayesian phylogenetics, two species-delimitation programs, and population genetics analyses. IMPORTANCE Our study sheds new light on the population genetic structure of V. vermiformis and diverse Naegleria species. Using improved molecular markers and advanced analytical approaches, we discovered that N. americana, previously considered a single species, actually contains multiple distinct lineages, as revealed by COI sequencing. These lineages are highly differentiated, with little gene flow between them. Our findings demonstrate that the genus Vermamoeba holds multiple cryptic species, requiring a significant taxonomic revision in light of multilocus sequence analyses. These results advance our understanding of the ecology, molecular systematics, and biogeography of these genera and species complexes at both regional and global scales. This study has significant implications for diagnosing amoebal infections and evaluating health risks associated with FLA in domestic and recreational waters.

Thyroid-Friendly Soft Materials as 3D Cell Culture Tool for Stimulating Thyroid Cell Function.

The disruption of thyroid hormones because of chemical exposure is a significant societal problem. Chemical evaluations of environmental and human health risks are conventionally based on animal experiments. However, owing to recent breakthroughs in biotechnology, the potential toxicity of chemicals can now be evaluated using 3D cell cultures. In this study, the interactive effects of thyroid-friendly soft (TS) microspheres on thyroid cell aggregates are elucidated and their potential as a reliable toxicity assessment tool is evaluated. Using state-of-the-art characterization methods coupled with cell-based analysis and quadrupole time-of-flight mass spectrometry, it is shown that TS-microsphere-integrated thyroid cell aggregates exhibit improved thyroid function. Specifically, the responses of zebrafish embryos, which are used for thyroid toxicity analysis, and the TS-microsphere-integrated cell aggregates to methimazole (MMI), a known thyroid inhibitor, are compared. The results show that the thyroid hormone disruption response of the TS-microsphere-integrated thyroid cell aggregates to MMI is more sensitive compared with those of the zebrafish embryos and conventionally formed cell aggregates. This proof-of-concept approach can be used to control cellular function in the desired direction and hence evaluate thyroid function. Thus, the proposed TS-microsphere-integrated cell aggregates may yield new fundamental insights for advancing in vitro cell-based research.

The Toxicological Analysis and Toxicological Risk Assessment of Chosen Elemental Impurities (Ag, Au, Co, Cr, Cs, Li, Mo, Se, and Sr) in Green Tea (Camellia sinensis (L.)) Infusions

Our study's objective is to evaluate the potential health effects of elemental impurities (Ag, Au, Co, Cr, Cs, Li, Mo, Se, and Sr) found in green tea infusions (Camellia sinensis (L.)). The ICP-MS-based methodology was employed for elemental analysis and a detailed health risk evaluation based on weekly consumption (μg/L of infusion/week). The provisional tolerable weekly intake (PTWI), established by the Joint FAO Expert Committee on infusion/week/month based on existing literature data, was then compared to the subjects with data from the available literature. The exposure of the study items to Co ranged from 0.07904 to 0.85421 μg/day. On the contrary, the ICH (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) guidelines state that the established permitted daily exposure PDE (oral exposure) for Co is 50 μg/day. The PDE of lithium is around 560 μg/day, and according to our study, the estimated daily exposure of the evaluated products to Li fell between 0.0185 and 0.7170 μg/day. Our research also revealed modest concentrations of Cs (0.399-2.654 μg/L), Mo (0.0113-0.107 μg/L), and Sr (9.848-22.331 μg/L) in infusions. The recognized PDE for molybdenum is approximately 3400 μg/day. Only two samples contained silver, and when considering daily consumption, the predicted daily exposure to Ag is between 4.4994 and 0.03122 μg/day. The amounts of all evaluated elements in a daily dose of green tea infusions should not harm the consumer's health. Further considerations should take aspects, such as constant change and environmental pollution, into account.

Characteristics of Soil Heavy Metal Pollution and Health Risk Assessment in Urban Parks at a Megacity of Central China

In this study, we compared the concentrations of the heavy metals Cd, Cr, Cu, Zn, Ni, and Pb in the surface soils of urban parks in Wuhan, Hubei Province, with those in the surface soils of urban parks worldwide. The soil contamination data were assessed using enrichment factors and spatial analysis of heavy metals using inverse distance weighting and quantitative analysis of heavy metal sources with a positive definite matrix factor (PMF) receptor model. Further, a probabilistic health risk assessment of children and adults using Monte Carlo simulation was performed. The average Cd, Cr, Cu, Zn, Ni, and Pb concentrations in the surface soils of urban parks were 2.52, 58.74, 31.39, 186.28, 27.00, and 34.89 mg·kg-1, respectively, which exceeded the average soil background values in Hubei. From the inverse distance spatial interpolation map, heavy metal contamination was primarily observed to be present to the southwest of the main urban area. The PMF model resolved four sources: mixed traffic and industrial emission, natural, agricultural, and traffic sources, with relative contributions of 23.9%, 19.3%, 23.4%, and 33.4%, respectively. The Monte Carlo health risk evaluation model demonstrated negligible noncancer risks for both adult and child populations, whereas the health effects of Cd and Cr on children were a concern for cancer risks.

Groundwater non-carcinogenic health risk comprehensive assessment based on DLAFVRT model in an island city

The long-term leakage of surface contaminants can severely affect the quality of shallow groundwater, thereby significantly affecting human health. This paper analyzed the spatial variations in groundwater non-carcinogenic health risk on the west coast of the Wailingding Island. A novel method for groundwater health risk assessment combining Modflow, remote sensing, and geographic information system (GIS) data was proposed. The DLAFVRT model, which included seven indicators: Groundwater depth (D), Land-use type (L), Aquifer medium (A), Fracture (F), Vegetation coverage (V), Net recharge (R) and Terrain slope (T), and potential non-carcinogenic health risk were based on the groundwater flow field and pollutant transport model constructed by Modflow and MT3DMS. The analytic hierarchy process was used to determine the weight of each index and optimize the model. Finally, the two evaluation results were superimposed to obtain a comprehensive evaluation of the groundwater health risk. The health risk zoning map showed that in the study area, the heavy-risk area accounted for 16.83%, high-risk area accounted for 26.45%, medium-risk area accounted for 42.25%, and low-risk area accounted for 14.47%. Moreover, approximately half of the areas were rated as high-risk or above, indicating that groundwater is susceptible to surface pollutants. Based on the groundwater numerical simulations, the multi-index groundwater health risk comprehensive evaluation system developed by combining groundwater vulnerability and human health risk provides a theoretical reference basis for the scientific management and rational allocation of groundwater resources.

Nematode as a biomonitoring model for evaluating ecological risks of heavy metals in sediments from an urban river

Heavy metals have attracted much attention due to their irreversibility, persistence, concealment and bioaccumulation. Biomonitoring method combined chemical analysis can be well evaluate health risks of heavy metals in the environment. In this study, eleven sediments and water samples were collected along Xihe River, which was polluted by heavy metals in Shenyang city of China. The content of multiple heavy metals in these samples was determined by inductively coupled plasma mass spectrometry. 18S rRNA gene sequencing was performed to identify the composition and diversity of nematodes in fine River sediments. The biological toxicity of water-soluble extracts from the samples was further assessed by referring to different endpoints of Caenorhabditis Elegans. The results indicated that the risk of heavy metals in Xihe River was high (potential ecological risk index = 308.75), in which Hg and Cd are the main contributing factors. The relative abundance of nematodes complemented the chemical analysis result, Enoplida, Mononchida, Triplonchida, and Chromadorida nematodes presented a significant positive correlation with the concentration of heavy metals. Specially, Chromadorida nematodes were sensitive to changes in heavy metals in Xihe River, which was significant positively correlated with As, Pb and V. Therefore, nematodes such as Chromadorida can be applied in environmental monitoring to evaluate the health risks of heavy metals.

Assessment of water quality, trace metal pollution, source apportionment and health risks in the groundwater of Chakwal, Pakistan.

Groundwater quality evaluation is the main concern in the regions like Chakwal where it is major source of water for drinking and irrigation due to low storage capacity of the surface water and lack of proper irrigation system. The aim of the present study was to evaluate various physicochemical parameters (pH, EC, TDS, DO, TA, TH and chlorides) and selected essential/toxic trace metal concentrations (Na, K, Ca, Mg, Sr, Li, Ag, Zn, Fe, Cu, Co, Mn, Cr, Cd, and Pb) in order to explore their distribution, correlation, spatial variations and health risk assessment. Average concentration of some trace metals (Co, Cd and Pb) and physicochemical parameters (EC, TDS, and alkalinity) were found to exceed the national/international standards. Multivariate methods of analysis showed strong associations among Fe-Li-K, Sr-Mg-Ca, Cd-Mn, Cu-Zn, Ag-Co, and Cr-Pb-Na which were significantly contributed by anthropogenic activities. Irrigation water quality index exhibited intermediate suitability of the groundwater for irrigation purpose. Health risk evaluation of the trace metals revealed significant non-carcinogenic risks for Cd, Co and Pb (HQing > 1) especially for children. Similarly, significant carcinogenic risk was found to be associated with Pb and Cr which exceeded the safe limit, suggesting the lifetime carcinogenic risk associated with these metals in the groundwater. The present health risk problems should be considered on top priority and immediate actions should be taken to safeguard the water quality in the study area.

Evaluation of Human Health Risks Associated with Groundwater Contamination and Groundwater Pollution Prediction in a Landfill and Surrounding Area in Kaifeng City, China

Landfill accumulation can cause its leachate to seep into groundwater, which can lower the quality of local groundwater. Exploring the risks of groundwater contamination to human health in the area around a landfill can offer a clear understanding of the current situation of regional groundwater and provide a theoretical basis for groundwater remediation and governance. By taking a landfill in Kaifeng City, China as the research object, this study explored the chemical types and sources of groundwater in the study area, used the entropy-weighted water quality index (EWQI) to evaluate the groundwater quality and assessed human health risks in the study area. The results show that the groundwater in the study area is neutral (7.14 ≤ pH ≤ 7.86), and the water chemical type is HCO3−—Ca·Na. The EWQI results indicated that the overall water quality in the study area ranges from 48.4 to 250.26, which is above the medium level, and that the local water quality is poor. The deterioration of groundwater quality in the study area is mainly influenced by NH4+-N, Mn, As, F− and Pb. According to the human health risk assessment model, the non-carcinogenic risk to humans through oral and dermal exposure can be assessed. In this paper, five ions, NH4+-N, Mn, As, F− and Pb in groundwater, were selected for the analysis of groundwater in the study area to assess non-carcinogenic risk to humans through oral administration. The results showed that the hazard quotient (HQ) values for NH4+-N, Mn, As, F− and Pb varied in the following ranges: 9.14 × 10−4—0.03; 0.07—0.22; 0.02–0.07; 0.16—0.23; and 0.01—0.13, respectively (all of these are less than 1, and so the potential risks to human health can be ignored). The characteristic pollutant Pb was selected as a predictor to study the influence on groundwater quality in eastern fish ponds and farmlands under continuous leakage. The leakage can be detected timeously to reduce the effects downstream by using enhanced monitoring measures.

In vitro digestion of ESC-resistant Escherichia coli from poultry meat and evaluation of human health risk.

The spread of antimicrobial resistance (AMR) has become a threat against human and animal health. Third and fourth generation cephalosporins have been defined as critically important antimicrobials by The World Health Organization. Exposure to Extended spectrum cephalosporin-resistant E. coli may result in consumers becoming carriers if these bacteria colonize the human gut or their resistance genes spread to other bacteria in the gut microbiota. In the case that these resistant bacteria at later occasions cause disease, their resistance characteristics may lead to failure of treatment and increased mortality. We hypothesized that ESC-resistant E. coli from poultry can survive digestion and thereby cause infections and/or spread their respective resistance traits within the gastro-intestinal tract. In this study, a selection of 31 ESC-resistant E. coli isolates from retail chicken meat was exposed to a static in vitro digestion model (INFOGEST). Their survival, alteration of colonizing characteristics in addition to conjugational abilities were investigated before and after digestion. Whole genome data from all isolates were screened through a custom-made virulence database of over 1100 genes for virulence- and colonizing factors. All isolates were able to survive digestion. Most of the isolates (24/31) were able to transfer their bla CMY2-containing plasmid to E. coli DH5-á, with a general decline in conjugation frequency of digested isolates compared to non-digested. Overall, the isolates showed a higher degree of cell adhesion than cell invasion, with a slight increase after digestion compared non-digested, except for three isolates that displayed a major increase of invasion. These isolates also harbored genes facilitating invasion. In the virulence-associated gene analysis two isolates were categorized as UPEC, and one isolate was considered a hybrid pathogen. Altogether the pathogenic potential of these isolates is highly dependent on the individual isolate and its characteristics. Poultry meat may represent a reservoir and be a vehicle for dissemination of potential human pathogens and resistance determinants, and the ESC-resistance may complicate treatment in the case of an infection.

Evaluasi Risiko Kesehatan dan Keselamatan Kerja dengan Metode Hirarc pada Proyek Pembangunan Sistem Penyediaan Air Baku Bendungan Pengga Kabupaten Lombok Tengah

AbstractThe construction of Pengga Dam bulk water supply system in Central Lombok district has considerable complexity that requires health and safety risk evaluation management, that include part of the project plan and control. This construction consist of several working stage: intake work, jetty work, galvanized pipe connection work, HDPE pipe connection work and pipe bridge construction work. This study uses HIRARC (Hazard Identification Risk Assessment and Risk Control) method consisting of risk identification, risk assessment, and risk control. Risk assessment is explored through field observations and job supervision. Result of the study identifies risks on 7 working stages in which there are any identified potential hazards with multi-levels of risk, in which are low risk, medium risk, up to high risk level. The hazard risk is caused by the absence of occupational safety and health training, inadequate work methods and equipment, the absence of safety signs and complete standardized PPE, also the absence of supervision carried out by the job executor. Risk control should be undertaken in the form of administrating Standard Operating Procedure (SOP) and appropriate use of PPE when carrying out job activities and when in site. Keywords: Hazard Identification Risk Assessment and Risk Control, Bulk Water

Hydrogeochemical Characteristics, Water Quality, and Human Health Risks of Groundwater in Wulian, North China

Groundwater shortage and pollution are critical issues of global concern. In Wulian County, a typical hilly area, groundwater is the main source of water supply. This study investigates the current situation of groundwater pollution in Wulian City through the analysis of groundwater water chemistry characteristics, water quality evaluation, and health risk evaluation. After the analysis of the controlling factors of chemical components in groundwater and the analysis of ion sources, the main ion sources in groundwater were determined. The results showed that the major cations in groundwater were Ca2+ and Na+ and the major anions were HCO3− and SO42−. Nevertheless, NO3− exceeded the standard to different degrees in pore water (PW), fissure pore water (FPW), and fissure water (FW). The minimum NO3− concentration exceeded the standard in FW. Under the influence of rock weathering and salt rock dissolution, the main hydrochemical types of groundwater were the HCO3-Ca, HCO3-Ca·Mg, and SO4·Cl-Ca·Mg types. According to the water quality evaluation and health risk assessment, the FW area in the south had the highest water quality, where Class I water appeared and potable water was more widely distributed. The PW and FPW areas in the north had lower water quality, with higher health risks. Category V water gradually appeared in the FPW area, which is not suitable as a water supply source. Factor analysis and ion ratio analysis showed that the study area is strongly affected by anthropogenic factors. These research methods have important reference value to the research of groundwater pollution status.

Air Quality Versus Perceived Comfort and Health in Office Buildings at Western Macedonia Area, Greece during the Pandemic Period

This study investigated the indoor environment quality (IEQ) of eight office buildings of interest due to: (a) their location at the region of Western Macedonia, Greece, which is an area characterized by aggravated air quality and is currently in a transition phase because of changes in the energy production strategy to reduce the use of lignite as an energy fuel; and (b) the survey’s timing, characterized by new working conditions implemented during the COVID-19 pandemic period. In-site measurements were performed to identify the indoor air pollutants to which the occupants were exposed, while questionnaires were collected regarding the participants’ perception of the working environment conditions, indoor air quality, and health symptoms. The statistical analysis results showed that the most-reported health symptoms were headache, dry eyes, and sneezing. The acceptance of new working conditions showed a significant correlation with their overall comfort and health perception. Occupants in offices with higher pollutant concentrations, such as NO2, benzene and toluene, were more likely to report health symptoms. The evaluation of the plausible health risks for the occupants of the buildings with carcinogenic and no-cancer models showed that health problems could exist despite low pollutant concentration levels.

Public Health Risk Evaluation through Mathematical Optimization in the Process of PPPs.

The public sector is becoming increasingly appealing. In the context of declining public money to support health studies and public health interventions, public-private partnerships with entities (including government agencies and scientific research institutes) are becoming increasingly important. When forming this type of cooperation, the participants highlight synergies between the private partners and the public's missions or goals. The tasks of private and public sector actors, on the other hand, frequently diverge significantly. The integrity and honesty of public officials, institutions, trust, and faith in those individuals and institutions may all be jeopardized by these collaborations. In this study, we use the institutional corruption framework to highlight systemic concerns raised by PPPs affiliated with the governments of one of South Asia's countries. Overall analytical frameworks for such collaborations tend to downplay or disregard these systemic impacts and their ethical implications, as we argue. We offer some guidelines for public sector stakeholders that want to think about PPPs in a more systemic and analytical way. Partnership as a default paradigm for engagement with the private sector needs to be reconsidered by public sector participants. They also need to be more vocal about which goals they can and cannot fulfill, given the limitations of public financing resources.

Analysis of Critical Source of Potentially Harmful Elements in Urban Road Dust During Winter in Taiyuan Based on Multiple Attribute Decision Making Method

In order to analyze the critical sources of potential harmful elements (PHEs) in road dust from Taiyuan during winter, 40 road dust samples were collected. The contents of PHEs, including As, Cd, Pb, Ni, Cr, Cu, and Zn, in the road dust samples were measured using inductively coupled plasma mass spectrometry and atomic fluorescence spectrometry. The ecological risks and human health risks posed by dust PHEs were assessed using NIRI and a health risk evaluation model recommended by USEPA, respectively. The sources of dust PHEs were identified by using the combination of principal component analysis and positive matrix factorization (PMF); the total PHE contents and the ecological risks and human health risks posed by PHEs in dust were apportioned to the PHE sources based on the PMF results; subsequently, the critical source of dust PHEs was determined using the multiple attribute decision making method (MADM). The results demonstrated that: 1 the average concentrations of As, Cd, Pb, Ni, Cr, Cu, and Zn were 17.92, 0.32, 69.10, 30.06, 107.74, 73.37, and 268.49 mg·kg-1, respectively, which were higher than the corresponding background values of soil in Taiyuan, indicating that the PHEs had accumulated in road dust; the mean value of NIRI was 63.86, demonstrating that PHEs in dust posed moderate risks, and the dust PHEs pollution was controllable. 2 Human health risk assessment indicated that exposure to PHEs in dust did not pose serious non-carcinogenic or carcinogenic risks. Ingestion was the most important pathway for exposure to PHEs in road dust that damages human health, and As and Cr have been found to pose the most risks among the seven PHEs. 3 The present study found three main sources of PHEs measured in the dust: natural, traffic, and industrial, which accounted for 35.95%, 40.25%, and 23.82% of the total concentrations of PHEs, respectively. 4 Industrial emissions contributed the least to the total PHEs contents in dust; however, the PHEs released from industrial sources caused relatively high risks, with the results of MADM indicating that industrial sources were the most critical source for dust PHEs. Our results indicated that the critical source identification of PHEs, which was determined to be the most pernicious source, could provide reference for subsequent pollution source control.

Photodegradation of xylene isomers: Kinetics, mechanism, secondary pollutant formation potential and health risk evaluation

Photodegradation technology has been widely applied in the purification of industrial aromatic hydrocarbons. However, whether this technology efficiently removes the pollutants to prevent secondary pollution and health risk is still unclear. Here, the photodegradation processes of three xylenes were compared under designed reaction atmospheres and light sources. Xe lamp showed poor photodegradation ability toward xylenes, no matter in N2 or N2+O2 system, while much higher photodegradation performance of xylenes were obtained under ultraviolet (UV) and vacuum ultraviolet (VUV) irradiation, especially in N2+O2+VUV system, where 97.9% of m-xylene, 99.0% of o-xylene or 87.5% of p-xylene with the initial concentration of 860 mg/m3 was removed within 240 min. The xylenes underwent three processes of photo-isomerization, photodecomposition and photo-oxidation to produce intermediates of aromatics, alkanes and carbonyls. Among them, the photo-isomerization products showed the highest concentration percentage (e.g., ≥50% in o-xylene system), confirming that photo-isomerization reaction was the dominated photodegradation process of xylenes. Moreover, these isomerized products not only contributed about 97% and 91% to the formation potential of O3 (OFP) and secondary organic aerosols (SOAFP), but also displayed obvious non-carcinogenic risk, although one of photodecomposition product—benzene showed the highest occupational exposure risk. Therefore, the secondary pollution and health risks of photodegradation products of xylenes were non-ignorable, although the OFP, SOAFP and health risks of the generated products reduced at least 4.5 times in comparison with that of the degraded xylenes. The findings are helpful for the appropriate application of this technology in the purification of industrial organic waste gas.

Changes in Arsenic Speciation in Wild Edible Fungi after Different Cooking Processes and Gastrointestinal Digestion.

Arsenic (As) is enriched in wild edible fungi, which is one of the main important sources of As in humans' diet. In this study, two wild edible fungi were employed for investigation: (1) Pleurotus citrinopileatusone, which contains a high content of inorganic As (iAs) and (2) Agaricus blazei Murill, which contains a high content of organic As. This study investigated the changes in As content and its speciation after different daily cooking methods. We found that the content of As in Pleurotus citrinipileatus and Agaricus blazei Murill reduced by soaking plus stir-frying by 55.4% and 72.9%, respectively. The As content in Pleurotus citrinipileatus and Agaricus blazei Murill decreased by 79.4% and 93.4%, respectively, after soaking plus boiling. The content of As speciation in dried wild edible fungi reduced significantly after different treatments. Among them, iAs decreased by 31.9~88.3%, and organic As decreased by 33.3~95.3%. This study also investigated the bioaccessibility of As in edible fungi after different cooking processes via an in-vitro physiologically based extraction test (PBET). The results showed that the bioaccessibility of As was relatively high if the edible fungi were uncooked, boiled, or stir-fried. The gastric (G) bioaccessibility of As ranged from 51.7% to 93.0% and the gastrointestinal (GI) bioaccessibility of As ranged from 63.5% to 98.1%. Meanwhile, the bioaccessibility of inorganic As was found to be as high as 94.6% to 151%, which indicates that further evaluation of the potential health risks of wild edible fungi is necessary.

One-year post-exposure assessment of 14C-few-layer graphene biodistribution in mice: single versus repeated intratracheal administration.

Research on graphene-based nanomaterials has experienced exponential growth in the last few decades, driven by their unique properties and their future potential impact on our everyday life. With the increasing production and commercialization of these materials, there is significant interest in understanding their fate in vivo. Herein, we investigated the distribution of 14C-few-layer graphene (14C-FLG) flakes (lat. dim. ∼ 500 nm) in mice over a period of one year. Furthermore, we compared the effects of repeated low-dose and acute high-dose exposure by tracheal administration. The results showed that most of the radioactivity was found in the lungs in both cases, with longer elimination times in the case of acute high-dose administration. In order to gain deeper insights into the distribution pattern, we conducted ex vivo investigations using μ-autoradiography on tissue sections, revealing the heterogeneous distribution of the material following administration. For the first time, μ-autoradiography was used to conduct a comprehensive investigation into the distribution and potential presence of FLG within lung cells isolated from the exposed lungs. The presence of radioactivity in lung cells strongly suggests internalization of the 14C-FLG particles. Overall these results show the long-term accumulation of the material in the lungs over one year, regardless of the administration protocol, and the higher biopersistence of FLG in the case of an acute exposure. These findings highlight the importance of the exposure scenario in the context of intratracheal administration, which is of interest in the evaluation of the potential health risks of graphene-based nanomaterials.