Dust Samples Research Articles

Assessment of Human Health Risk Caused by Heavy Metals in Kiln Dust from Coal-Fired Clay Brick Factories in Türkiye

AbstractHeavy metal (HM) pollution from natural processes and different anthropogenic activities pose significant human and environmental health risks because of their stability, non-degradable properties, and high toxicity. HM released into the air in the form of dust can enter the human body via ingestion, inhalation, and dermal contact. Keeping in mind the significance of estimating the risk from HM in different environments, the carcinogenic and non-carcinogenic health risks to workers caused by HM in kiln dust (KD) samples collected from coal-fired clay brick factories in the Western Black Sea Region of Türkiye were assessed for the first time in this study. The concentrations of major and minor oxides and HMs in the collected KD samples were analyzed using energy-dispersive X-ray fluorescence spectrometry. The average concentrations of Fe, Mn, Cr, Ni, V, Zn, Cu, As, Co and Pb analyzed in thirty-three KD samples were determined as 65444, 768, 251, 249, 248, 122, 60, 52, 42 and 16 mg/kg dw, respectively. The average levels of Ni, As, Cr, Co and Cu exceed the maximum contaminant levels recommended in the Turkish Regulation on Control of Soil Pollution. Carcinogenic and non-carcinogenic human health risk assessments for workers via three exposure pathways were carried out, estimating the hazard index (HI) and total carcinogenic risk (TCR) index, respectively. The HI values (< 1) revealed no possible non-carcinogenic health risk due to exposure to all HMs in the studied KD samples. The average TCR value revealed that the potential cancer risks for Ni, As, Cr, and Pb were slightly above the safe limit and required monitoring and further investigation for these HMs.

End-of-life vehicle dismantling activity emits large quantities of phthalates and their alternatives: New insights on environmental sources and co-exposure risks

Automotive interiors have been identified as significant sources of various chemicals, yet their occupational hazards for end-of-life vehicle (ELV) dismantlers remain poorly characterized. Herein, eight classes of plasticizers, including 11 phthalates esters (PAEs) and 16 non-phthalates esters (NPAEs), were detected in dust samples from inside and outside ELV dismantling workshops. Moreover, indoor dust from ordinary households and university dormitories was compared. The indoor dust from the ELV dismantling workshops contained the highest concentrations of plasticizers (median: 594 μg/g), followed by ordinary households (296 µg/g), university dormitories (186 µg/g), and outdoor dust (157 µg/g). PAEs remained the dominant plasticizers, averaging 11.7-fold higher than their NPAE alternatives. Specifically, diisononyl phthalate and trioctyl trimellitate were notably elevated in workshop dust, being 15.5 and 4.78 times higher, respectively, than in ordinary household dust, potentially indicating their association with ELV dismantling activities. The estimated daily intake of occupational ELV dismantling workers was up to five times higher than that of the general population. Moreover, certain dominant NPAEs demonstrated nuclear receptor interference abilities comparable to typical PAEs, suggesting potential toxic effects. This study is the first to demonstrate that ELV dismantling activities contribute to the co-emission of PAEs and NPAEs, posing a substantial risk of exposure to workers, which warrants further investigation.

The strength of outgassed porous dust aggregates

Context. Outgassing of dust-ice aggregates plays an important role on the surfaces of cometary nuclei as well as for snow-line crossings in protoplanetary disks. Aims. To assess the stability of desiccated dust aggregates, we measured the tensile strength of silica dust samples over a wide range of volume filling factors. Methods. We produced these silica dust samples over a wide range of volume filling factors by gently evaporating dust-ice mixtures with various dust-to-ice mass ratios under vacuum conditions. The tensile strengths of these samples were then measured using the standardized Brazilian disk test. Experiments were performed in a vacuum and at room temperature but were also compared to measurements in air at room temperature and in a vacuum at elevated temperatures. Results. For spherical amorphous silica dust, we find no influence of the environmental conditions (air, vacuum, or heating) on the measured tensile strength. However, for angular crystalline silica dust we see a strong increase in tensile strength in a vacuum compared to air and an even higher increase when the samples are heated in a vacuum. For the spherical silica dust samples, we find a characteristic increase in the tensile strength with decreasing particle size. The tensile strength of samples with identical particle sizes increases strongly with an increasing volume filling factor. Extrapolation of our data to a volume filling factor of 0.1 (90% porosity) shows that a tensile strength as low as 1 Pa can be reached. Conclusions. Numerical simulations show that evaporating water ice in the subsurface layers of comets can reach gas pressures of ~1 Pa. Thus, a desiccated dust layer with a 10% volume filling factor should be detachable and released into the cometary coma. Using a relation between the tensile strength and the critical fragmentation energy, we predict the break-up speed of dust aggregates in mutual collisions as a function of the volume filling factor. Furthermore, we discuss the susceptibility of the aggregates to ram pressure. These values are relevant for protoplanetary disk research and for meteoroids entering planetary atmospheres.

Assessment of polycyclic aromatic hydrocarbon (PAH) levels and health risks in kitchen dust from wood, kerosene, and gas cooking systems in Cumilla, Bangladesh

This study investigates the presence of polycyclic aromatic hydrocarbons (PAHs) in kitchen dust from households in the Cumilla District of Bangladesh, utilizing three different cooking systems: wood, kerosene, and gas. Sixty dust samples were collected from various kitchen surfaces and analyzed for 18 PAH compounds. The extraction and analysis of PAHs were performed using gas chromatography-mass spectrometry (GC-MS) with selective ion monitoring (SIM) mode. The results indicated significant variations in PAH concentrations across different cooking systems, with the highest levels observed in kitchens using wood stoves, followed by kerosene and gas stoves. Diagnostic ratios were used to identify the sources of PAHs, revealing a combination of pyrogenic and petrogenic origins. Health risk assessments, including Incremental Lifetime Cancer Risk (ILCR) and Hazard Index (HI), were conducted to evaluate the potential risks associated with PAH exposure. The findings demonstrated a higher carcinogenic risk associated with wood stove systems, while kerosene and gas systems posed comparatively lower risks. The study's findings have practical implications for public health and policy development, as they underscore the need for continuous monitoring of indoor PAH levels and the development of policies to mitigate exposure, highlighting the critical importance of addressing indoor pollution to ensure public health safety.

Health Risk Assessment of Road-Dust-Bound Heavy Metals via Ingestion Exposure from One Typical Inland City of Northern China: Incorporation of Sources and Bioaccessibility

Heavy metals in road dust pose potential health risks to humans, while oral bioaccessibility and sources are all important factors influencing this health risk. However, few prior studies have combined them for health risk analysis. In this study, road dust samples were collected from different geographical locations of Jinan (west area, WA; central area, CA; and east area, EA) to analyze the source-specific and bioaccessibility-based health risks of heavy metals. The mean concentrations of heavy metals in the three areas were CA > EA > WA, with Cd, Cu, Mn, Pb, and Zn exceeding their corresponding background values. A source analysis using a Positive Matrix Factorization (PMF) model showed that traffic emissions were the main source of heavy metals in the WA and CA, while industrial activities were the main source in the EA. The mean bioaccessibility of heavy metals extracted using the Solubility Bioaccessibility Research Consortium (SBRC) method followed the order of Cd (75.5%) > Zn (42.2%) > Mn (42.1%) > Pb (42.0%) > Cu (32.9%) > As (23.6%) > Ni (20.1%) > V (16.8%) > Cr (13.3%). According to the combined source analysis, traffic was the primary risk factor in the WA (54.5 and 58.3% of NCR and CR, respectively) and CA (61.8 and 51.2%), with solid waste being the main risk factor in the EA (41.9 and 51.3%). In oral bioaccessibility testing, lower non-carcinogenic (<1.0) and carcinogenic risks (<1 × 10−6) of heavy metals were observed than those based on the total metal content. More importantly, As (43.4%) was replaced by V (29.7%) as the main contributor to NCR. Source-specific and bioaccessibility-based health risk assessments can accurately identify priority pollutants and heavy metals in urban road dust that need to be controlled. This provides more effective and accurate urban environmental risk management recommendations for sustainable urban development and population health.

Occurrence and human risk assessment of pharmaceutically active compounds (PhACs) in indoor dust from homes, schools and offices

This study investigates the current situation and possible health risks due to pharmaceutically active compounds (PhACs) including analgesics, antibiotics, antifungals, anti-inflammatories, psychiatric and cardiovascular drugs, and metabolites, in indoor environments. To achieve this objective, a total of 85 dust samples were collected in 2022 from three different Spanish indoor environments: homes, classrooms, and offices. The analytical method was validated meeting SANTE/2020/12830 and SANTE/12682/2019 performance criteria. All indoor dust samples except one presented at least one PhAC. Although concentration levels ranged from < LOQ to 18 µg/g, only acetaminophen, thiabendazole, clotrimazole, and anhydroerythromycin showed quantification frequencies (Qf %) above 19% with median concentrations of 166 ng/g, 74 ng/g, 25 ng/g and 14 ng/g, respectively. The PhAC distribution between dust deposited on the floor and settled on elevated (> 0.5 m) surfaces was assessed but no significant differences (p > 0.05, Mann–Whitney U-test) were found. However, concentrations quantified at the three types of locations showed significant differences (p < 0.05, Kruskal–Wallis H-test). Homes turned out to be the indoor environment with higher pharmaceutical concentrations, especially acetaminophen (678 ng/g, median). The use of these medicines and their subsequent removal from the body were identified as the main PhAC sources in indoor dust. Relationships between occupant habits, building characteristics, and/or medicine consumption and PhAC concentrations were studied. Finally, on account of concentration differences, estimated daily intakes (EDIs) for inhalation, ingestion and dermal adsorption exposure pathways were calculated for toddlers, adolescents and adults in homes, classrooms and offices separately. Results proved that dust ingestion is the main route of exposure, contributing more than 99% in all indoor environments. Moreover, PhAC intakes for all studied groups, at occupational locations (classrooms and offices) are much lower than that obtained for homes, where hazard indexes (HIs) obtained for acetaminophen (7%—12%) and clotrimazole (4%-7%) at the worst scenario (P95) highlight the need for continuous monitoring.

Health risk assessment of heavy metals in the dust street of Mehran city, as a busy city in religious times, Iran.

The concentration of various potentially toxic metals (Pb, Cd, As, Ni, Zn, and Cr) in street dust samples collected from Mehran city, Iran, was analyzed. The samples were obtained during normal traffic conditions, NTT, prior to the Arbaeen ceremony, as well as after the pilgrims' return, which corresponds to high traffic time, HTT. Street dust samples were analyzed for HM content using ICP-OES, following acid digestion. The subsequent evaluation of the data involved the application of the geo-accumulation index, enrichment factor, and potential ecological risk index (PER) and health risk assessment. The findings demonstrate a notable increase in the levels of HMs during HTT compared to the NTT. The highest enrichment values for Pb and Cd were observed in Mehran Street dust during the HTT. The mean of PER for all sampling points increased to 138.24, indicating a moderate-potential ecological risk at this time. Based on the health risk assessment, it was found that the hazard index for all samples was below one. The incremental lifetime cancer risk was below 10-6. This indicates that the exposed population is not exposed to substantial health risks. Despite the heavy traffic caused by the Arbaeen ceremony in this area and the high enrichment of HMs, along with potential ecological risks, no significant health risks were observed for individuals exposed to street dust. However, it is important to note that the continuation of this trend, in the absence of proper traffic management, could lead to significant environmental and health problems in the future.

Estimation of natural radioactivity and radiological hazards in aggregate (stone dust) used as building materials in South Africa

ABSTRACT In this study, the radioactivity concentrations of natural radionuclides (Uranium-238, Thorium-232, and Potassiumi-40) in aggregate/stone dust samples used for building construction purposes have been measured with thallium-doped sodium iodide (NaI(TI)) detector. The samples’ associated radiological hazard risks were calculated using standard radiological expressions. The mean values of Uranium-238, Thorium-232, and Potassiumi-40 activity concentrations in the studied Quarries’ samples were above the World mean values of 35, 30, and 400 Bq.kg−1 for radioactivity concentrations in building materials. The lowest and highest values of all the estimated radiological hazard indices were recorded in samples Afrisam C 5 and Afrimat 3.

Identification of House Dust Mite and the Risk Factor of Cronic Itch in Elderly

Introduction: Senile pruritus etiology is uncertain. However, well as intrinsic factors, one of the extrinsic risk factors causing pruritus is house dust mites (HDM) as. Aim of this study was to analyze the association between house dust mite density and the pruritus level among elderly residents. Methods: This is an observational study with cross-sectional design. The 34 elderly who met the criteria were included in this study. The pruritus level was obtained using questionnaire as to duration, degree, direction, disability, distribution (5D) itch scale based on NRS (numerical rating scale) categories divided into 4 categories (no, low, moderate, and severe itch). House dust mite density was checked using flotation method and the results categorized into low, moderate, and high density. The dust sample was checked for the species by microscope. The preventive activity to prevent the pruritus were also analyzed. The relationship between itch scale, preventive activity with HDM density was analyzed using STATA 17. Results and Discussion: A total of 34 elderly was included. Elderly were dominated with women (67.6%), moderate itch scale (38.2%) and moderate HDM density (58.8%). Most of the correlation between itch scale based NRS and preventive activity with HDM density p-value was not significant. But the elderly’s’ habit to clean the mattress was significantly correlated with HDM density (p=0.00). The Dermatophagoides sp were the dominant mites found in elderly’s’ room. Conclusion: Itch scale in elderly were not related with HDM density, but correlated with the habit to clean the mattress.

Appraisal of microplastic pollution and its related risks for urban indoor environment in Bangladesh using machine learning and diverse risk evolution indices

The widespread presence of Microplastics (MPs) is increasing in the indoor environment due to increasing annual plastic usage, which is becoming a global threat to human health. Therefore, this is the first research in Bangladesh to identify, and characterize, MP pollution and its allied threats to human health in the indoor urban environment, where 80 household dust samples were collected from the whole study area. The presence of MPs in household dust of the urban indoor environment was 25.8 ± 6.43 particles/g with a significant variety, whereas the fiber shape (73%), 0.5–1.00 mm ranged MPs size (58%), blue color (21%), and polystyrene polymer (34%) was the most ubiquitous MPs category. The pollution load index (1.61–2.96) indicated significant pollution due to the high abundance of MPs. Besides, other risks evaluating indices including contamination factor (1.00–3.51), and Nemerow pollution index (1.60–3.51) represent moderate to high MP-induced pollution. The polymer hazard index (119.54 ± 70.34) indicated significant risks for the selected polymers to the indoor environment living inhabitants. Machine learning approaches, especially random forest and support random vector machine were effective in predicting the number of MPs, where EC, salinity, pH, OC, and texture classes acted as controlling factors. Children and adults might be ingesting 4.12 ± 1.01 and 2.27 ± 0.57 particles/day through the ingestion exposure route, which has significant health effects. Polymer-associated lifetime cancer risk assessment results show that there are moderate risks for both adults and children, but children tend to be more susceptible to MP risks. The overall study found that Dhaka was the most severely MPs induced risky division among the others. This study reveals that high quantities of MPs in indoor environments could pose a serious health hazard' to different exposure groups.

Tribocharged solids in protoplanetary discs: internal and external discharge time-scales

ABSTRACT Particles regularly tribocharge in collisions. Here, we study how long charges can persist on such particles in the environment of a protoplanetary disc. We set up three complementary experiments to quantify discharge time-scales. We first directly measure the time dependency of charge on triboelectrically charged objects. For this aspect, we performed two long-time experiments under different environmental conditions. We find that the charge persists on the tribocharged bodies on time-scales between minutes and years. Discharge might be mediated by external ions or internally, by conduction. To constrain the latter, we also determined the specific electric resistance of dust samples as simulants for dust aggregates in protoplanetary discs. In this third experiment, we see an increase in resistivity at decreasing ambient pressure up to the limit of the instrument. These findings are consistent with the assumption that water on all relevant surfaces including dust grains within the pore space of aggregates is the main driver of discharge. Under disc conditions, the charge might persist for weeks to years. This leaves net-charged isolated grains in dense parts of the mid-plane of protoplanetary discs charged in between collisions.

Evaluation of dust and endotoxin exposure among rice mill workers in northeast India

Exposure to particulate matter and endotoxin can lead to acute and chronic respiratory problems in workers. A study was conducted to quantify particulate matter with an aerodynamic diameter of ≤10 μm (PM10) and endotoxin levels in rice mills in northeast India. Sixty-four PM10 dust samples were collected from eight rice mills at two locations: the feeding and polishing sections for two varieties of paddy: Ranjit and Hali. Endotoxin exposures were analyzed using the Limulus Amoebocyte Lysate (LAL) gel clot test. The results showed that the geometric mean of the 8-h time-weighted average (TWA) PM10 dust concentration and endotoxin level in the rice mills were 10.69 mg/m³ and 2.2 EU/m³, respectively. Dust and endotoxin exposure were higher in the feeding section than in the polishing section. Endotoxin exposure in the feeding section during the milling of the Hali variety of paddy was 56.0 % higher than the milling of the Ranjit variety. Additionally, endotoxin exposure during the milling of the Hali variety was 24.2 % higher than that of the milling of the Ranjit variety in the polishing section. The dust exposure in the rice mills was 194.5 % higher than the standards set up by the United States Environmental Protection Agency. However, the exposure to endotoxin in rice mills was approximately 40.10 times below the recommended limit of 90 EU/m3.

Aliphatic and cyclic hydrocarbons in urban street dust from Riyadh city, Saudi Arabia: Levels, distribution, and sources

Dust particles contain diverse natural and anthropogenic organic compounds and act as local collectors of pollutants, particularly in urban settings. Samples of street dust were collected from various sites in Riyadh city in 2023. These samples were extracted using a dichloromethane–methanol mixture, and the resulting extracts were subjected to analysis through gas chromatography–mass spectrometry (GC–MS). The primary compounds identified included n-alkanes, methyl n-alkanoates (FAMEs), hopanes, steranes, polycyclic aromatic hydrocarbons (PAHs), plasticizers, tobacco miscellanies, and an unresolved complex mixture (UCM). Vegetation detritus constituted the primary natural source of organic compounds, ranging from 7.4 ± 3.5% to 15.0 ± 4.0%, and included fractional n-alkanes and FAMEs. Petroleum-related products from vehicular emissions, oil combustion, and spills were predominant, accounting for 73.3 ± 5.1% to 87.5 ± 4.8%, and included partial n-alkanes, hopanes, steranes, PAHs, and UCMs. Litterings from discarded plastics and tobacco smoking varied from 5.2 ± 1.3% to 12.0 ± 5.3%, and included phthalates, nicotine, and cotinine, as well as recreational drinks (coffee and tea beverages containing caffeine). The occurrence and distribution of natural and anthropogenic extractable organic matter in this arid urban area were influenced by local vegetation and human activities. The prevalence of anthropogenic organic compounds in Riyadh city's street dust depended on the location and type of urban activity, with elevated levels observed in high-traffic and industrial zones. Consequently, further investigations are necessary to understand the potential health effects of anthropogenic organic matter on city residents.

Phthalate monoesters accumulation in residential indoor dust and influence factors

Phthalate monoesters (mPAEs) possess biological activity that matches or even exceeds that of their parent compounds, phthalate esters (PAEs), negatively impacting humans. Indoor dust is the main carrier of indoor pollutants. In this study, indoor dust samples were collected from 46 households in Changchun City, Jilin Province, in May 2019, and particulate and flocculent fibrous dust was used as the research target to analyze the concentration and compositional characteristics of mPAEs, primary metabolites of five significant PAEs. The influence of factors such as architectural features and living habits in residential areas on exposure to mPAEs was explored. Ten suspected enzyme genes along with two metabolic pathways with the ability to degrade PAEs were screened using PICRUSt2. The results showed that the total concentrations of the five mPAEs in the indoor dust samples were particulate dust (11.49–78.69 μg/g) and flocculent fibrous dust (21.61–72.63 μg/g), respectively. The molar concentration ratio (RC) of mPAEs to corresponding PAEs significantly differed among chemicals, with MMP/DMP and MEP/DEP sporting the highest RC values. Different bacterial types have shown distinct influences against mPAEs and PAEs. Enzyme function and metabolic pathway abundance had a significant effect on the concentration of some mPAEs, mPAEs are most likely derived from microbial degradation of PAEs.

The spatial distribution and source of heavy metals in soil-plant-atmosphere system in a large coal mining area

Due to the lack coupling analysis of heavy metals in soil-plant-atmosphere system, the migration and transformation of heavy metals remains unclear. In this study, 240 surface (0–20 cm) soil samples, 365 plant samples and 168 atmospheric dust samples were collected in a large coal mining area, in which selected heavy metals arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), plumbum (Pb), zinc (Zn) were analyzed, to elucidate the spatial distribution and source of heavy metals and their bioavailability. According to the results of ArcGIS mapping analysis, the distribution patterns of Cd, Cu, Pb, and Zn in the three media are similar, while the distribution characteristics of Cr and Ni are highly consistent. The factors contributing to these spatial distribution characteristics of heavy metals could be associated with human activities and the characteristics of the elements. Compared with the background value, Zn, Cr, Pb in soil, Zn, Cr, Cu in plants and Zn, Pb, Cu in atmospheric dust apparently accumulated. The geological accumulation pollution index (Igeo) shows that there exist mild to moderate levels of Cr and Cd pollution in soil, and mild to moderate levels of Cd, Cr, Pb, and Zn pollution in the air. The evaluation of potential risks of heavy metals showed moderate ecological hazards in soil and strong ecological hazards in atmospheric dust. The sources of heavy metals were assessed using principal component analysis (PCA), land use type, and spatial analysis. Anthropogenic factors are the main sources of heavy metal content. Coal-related industrial processes related to coal, sewage irrigation, the use of agricultural chemicals, and vehicle emissions may be anthropogenic sources of heavy metals.

Features of the chemical composition of fine suspended particles in the atmospheric air of residential and industrial zones of the city of Sibay, Republic of Bashkortostan

Introduction. Atmospheric particulate matter as a negative environmental factor can be a significant hazard depending on their size, morphometric and physicochemical characteristics. The purpose of the study. To investigate the elemental composition of finely dispersed suspended particles in the atmospheric air of the industrial zones of the mining center of the Bashkir Trans-Urals - the city of Sibay. Materials and methods. Air sampling was carried out in the industrial area of ​​Sibay using an AVA-3-240/180-01 automatic three-channel air aspirator with AFA-VP-20 filters. Microscopy of samples and determination of the elemental composition of dust emissions were carried out at the Interdisciplinary Center “Analytical Microscopy” of the Kazan Federal University (Kazan) on a universal analytical complex for scanning field emission electron microscopy Merlin (Carl Zeiss). Results. On electron micrographs, there were identified particles of various sizes, mostly round in shape with clear edges, located solitary. In the automatic mode of processing the spectra, the peaks of the elements in the spectrum were automatically recognized and identified. In addition to carbon and oxygen, the calcium, iron, silicon, potassium, aluminium, copper, sulphur, sodium and magnesium are main chemical constituents of particulate matter encountered at all sampling points. Zinc was present in dust samples at three points, scandium, titanium, cobalt, barium, and manganese – only at one point. The possibility of the relation between the content of fine particles in the air and the increased incidence of cardiovascular, bronchopulmonary diseases, including asthma, in the population of Sibay is discussed. Limitations. The study of the elemental composition of fine dust in the city of Sibay was carried out using atmospheric air samples taken at 5 points located in residential and industrial areas. Conclusion. The increased content of fine particles in the atmospheric air of the city of Sibay increases the risks of respiratory and cardiovascular diseases, as well as other health abnormalities, in the population permanently residing near industrial zones. The obtained data on the parameters of dust particles are the basis for assessing the share contribution of industrial enterprises to air pollution and making management decisions to improve the environmental situation in the industrial center of the mining region.

Fungal Biodeterioration Risk in Monastic Libraries without Climate Control.

Fungi have always posed an unquestionable threat to heritage collections worldwide. Now, in a future of climate change, biological risk factors may have to be considered even more than before. Models and simulations to assess possible impacts a changing outdoor climate will have on indoor environments and, in turn, on biodeterioration are still underdeveloped and require a more substantial data basis. This study aimed at filling some of these knowledge gaps through a broad-based approach combining microclimatic and microbiological monitoring in four historic libraries in Austria with an uncontrolled indoor climate: Altenburg Abbey, Melk Abbey, Klosterneuburg Monastery and the Capuchin Monastery in Vienna. Data were generated from thermohygrometric sensors, cultivation-dependent air- and surface sampling and further surface dust sampling for cultivation-independent analyses. Results gave insights on the status quo of microbiological loads in the libraries and outdoor-indoor relationships. Influences of the geographic location and room-use on corresponding indoor fungal profiles were identified. Lower fungal diversities were found at the most rural site with the strongest climatic fluctuations and extreme values than in the most urban, sheltered library with a very stable climate. Further, the humidity-stabilizing potential of large collections of hygroscopic materials, such as books, was also examined. Implications for a sustainable approach to prevent future biodeterioration are discussed, supporting the long-term preservation of these valuable historic collections.

The oxidative stress-dependent pulmonary inflammation of inhalable multi-walled carbon nanotube-containing nano-concrete dust and its comparison with conventional concrete dust and DQ12

Nano-concrete, which is an admixture of nanomaterials in concrete recipes, has been investigated to overcome the limitations of existing concrete, such as its stability and strength. However, there is no information on the human health effects of broken-down dust released during the construction and demolition efforts. In this study, we prepared an inhalable fraction of multi-walled carbon nanotube-containing nano-concrete dust and performed comparative toxicity studies with conventional concrete dust and DQ12 using a rat intratracheal instillation model. Although the recipes for concrete and nano-concrete are entirely different, the pulverized dust samples showed similar physicochemical properties, such as 0.46–0.48 µm diameter and chemical composition. Both concrete and nano-concrete dust exhibited similar patterns and magnitudes, representing acute neutrophilic inflammation and chronic active inflammation with lymphocyte infiltration. The toxicity endpoints of the tested particles at both time points showed an excellent correlation with the reactive oxygen species levels released from the alveolar macrophages, highlighting that alveolar macrophages are the primary target cells and that the oxidative stress paradigm is the main toxicity mechanism of the tested particles. In addition, the toxicity potentials of both concrete and nano-concrete dust were more than 10 times lower than that of DQ12.

Health and environmental risk assessment of mercury in outdoor and indoor dust in artisanal and small-scale gold mining area in Amansie-west district in the Ashanti Region of Ghana.

Mercury (Hg) pollution around artisanal and small-scale gold mining (ASGM) areas has been of much concern. Many studies have reported elevated Hg concentrations in environmental media, but studies on dust relating to inhalation exposure of Hg around ASGM area are limited. In this study, we investigated Hg in indoor and outdoor dust to reveal environmental and human health risk around ASGM in Amansie West district, Ghana. Indoor and outdoor dust samples were collected from Manso Abore and Manso Nkwanta in Ashanti Region. Concentration of Hg in the samples were analyzed using a direct Hg analyzer. The mean and median value of Hg concentration in the indoor dust (n = 31) were 2.2 ± 3.6mg/kg and 0.72mg/kg respectively while that of the outdoor dust (n = 60) were 0.19 ± 0.48mg/kg and 0.042mg/kg, respectively. The mean and median Hg concentration in indoor dust were about 11 and 17 times higher respectively than that in the outdoor dust. The Hg concentration in the indoor dust was statistically significantly higher than that of the non-miner in Manso Abore (p < 0.05) but was not significant in Manso Nkwanta, probably due to higher mining activity. The geo-accumulation index of the outdoor dust ranged from unpolluted to extremely polluted while that of the indoor dust ranged from moderately polluted to extremely polluted. Health risk assessments suggested that there was no potential non-carcinogenic health effect for Hg exposure relating to the dust to residents living in rooms of miners and non-miners.

Phthalate Acid Esters (PAEs) in Indoor Dust from Decoration Material Stores: Occurrence, Sources, and Health Risks.

Phthalate acid esters (PAEs) are one of the most widely used plasticizers globally, extensively employed in various decoration materials. However, studies on the impact of these materials on indoor environmental PAE pollution and their effects on human health are limited. In this study, forty dust samples were collected from four types of stores specializing in decoration materials (flooring, furniture boards, wall coverings, and household articles). The levels, sources, exposure doses, and potential health risks of PAEs in dust from decoration material stores were assessed. The total concentrations of Σ9PAE (the sum of nine PAEs) in dust from all decoration-material stores ranged from 46,100 ng/g to 695,000 ng/g, with a median concentration of 146,000 ng/g. DMP, DEP, DBP, and DEHP were identified as the predominant components. Among all stores, furniture board stores exhibited the highest Σ9PAE (159,000 ng/g, median value), while flooring stores exhibited the lowest (95,300 ng/g). Principal component analysis (PCA) showed that decoration materials are important sources of PAEs in the indoor environment. The estimated daily intakes of PAEs through non-dietary dust ingestion and dermal-absorption pathways among staff in various decoration-material stores were 60.0 and 0.470 ng/kg-bw/day (flooring stores), 113 and 0.780 ng/kg-bw/day (furniture board stores), 102 and 0.510 ng/kg-bw/day (wall covering stores), and 114 and 0.710 ng/kg-bw/day (household article stores). Particularly, staff in wall-covering and furniture-board stores exhibited relatively higher exposure doses of DEHP. Risk assessment indicated that although certain PAEs posed potential health risks, the exposure levels for staff in decoration material stores were within acceptable limits. However, staff in wall covering stores exhibited relatively higher risks, necessitating targeted risk-management strategies. This study provides new insights into understanding the risk associated with PAEs in indoor environments.