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1.
Environ Sci Pollut Res Int ; 31(11): 16928-16939, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38326684

RESUMO

Heat losses in solar stills are high, which has led to a decrease in their thermal efficiency. Also, the production of these devices is limited to the presence of the sun, and their production stops during cloudy hours or at night. To solve these problems, in this experimental study, two cascade solar stills are examined under relatively similar conditions for sustainable freshwater production. One of these solar stills is modified with the phase change material and copper fins, and another one is a conventional cascade solar still without using the phase change material and copper fins. Paraffin was selected as a heat storage material to increase the time of desalination of water by the solar still. In addition, the copper fins are used to increase the conduction heat transfer in phase change material and provide better melting and solidification processes. To prolong the water path along the steps, the serpentine water path was considered. The results showed that at sunset hours, desalination efficiency with phase changing material and fins was increased. At 5 pm, the efficiency of the modified device was increased by 29% (on average) as compared to the conventional solar still without using phase changing material and fins. The rate of water production in conventional solar still in midday was higher compared to the modified solar still. However, in the sunset and night hours, the modified solar still has a higher production rate due to heat released from the thermal storage system.


Assuntos
Cobre , Água , Animais , Água Doce , Nadadeiras de Animais , Asbestos Serpentinas
2.
Environ Sci Pollut Res Int ; 31(6): 9857-9866, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38198092

RESUMO

Asbestos has been used extensively in the construction industry for its superior insulation properties before its health hazards were discovered and its use eventually banned. It is likely that many residential buildings built before the 2000s in Turkey contain asbestos. Therefore, it is important to raise awareness of the potential danger of asbestos exposure during demolition work and to identify asbestos-containing materials and ensure their safe removal and disposal. This study is executed to determine the residential dwellings containing asbestos in Izmir, Turkey. The research included field studies to determine asbestos presence in the buildings that were damaged during the 2020 earthquake. Air measurements and bulk samples were taken from 50 buildings that would go through the demolition process. Eleven buildings were found to contain asbestos which corresponds to 22%. The detected asbestos type was 60% chrysotile (white asbestos). Results could be helpful for future demolition work, which are conducted in the same region that includes buildings with similar properties. Also, it is expected that the database created for this study could be useful in other studies in Turkey, where accurate statistical data related with asbestos measurements is essentially non-existent.


Assuntos
Amianto , Indústria da Construção , Turquia , Materiais de Construção , Amianto/análise , Asbestos Serpentinas
4.
J Transl Med ; 21(1): 875, 2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-38041166

RESUMO

BACKGROUND: Asbestos lung content is regarded as the most reliable tool for causal attribution of malignant mesothelioma (MM) to previous asbestos exposures. However, there is a lack of studies on asbestos burden in lungs of MM patients in comparison with healthy individuals. This study aims to provide such a comparison, investigating, as well, differences in asbestos lung burden with sex and time trends. METHODS: Asbestos lung content has been assessed on formalin-fixed lung fragments using scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS) on individuals deceased from MM (cases) and healthy subjects without any lung disease who died from violent causes (controls) between 2005 and 2023. RESULTS: Asbestos and asbestos bodies (ABs) were found, respectively, in 73.7% and 43.2% of cases and in 28 and 22% of controls; in MM cases the most represented asbestos types were crocidolite and amosite, whereas in controls it was tremolite-actinolite asbestos. The concentration of both asbestos fibers and ABs was statistically significantly higher in MM cases compared to controls. The mean asbestos fibers width was also significantly higher in cases than controls. Males and females with MM showed similar asbestos and ABs concentrations, but females had higher concentrations of chrysotile, and significantly lower fibers width compared to males. Time trends show that MM lung asbestos concentrations decreased starting in 2011. DISCUSSION: The results suggest a correlation between asbestos burden in lungs and MM risk. The different concentration of chrysotile, as well as the different width of asbestos fibers in MM males and females might reflect a sex difference in response of the lung microenvironment to inhaled asbestos. Finally, this study provides the first pathological evidence of the effect of the ban of asbestos use, demonstrating a significant decrease of asbestos lung content after 2011.


Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Humanos , Feminino , Masculino , Mesotelioma Maligno/complicações , Asbestos Serpentinas , Estudos de Casos e Controles , Mesotelioma/patologia , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/patologia , Pulmão/patologia , Microambiente Tumoral
5.
Crit Rev Toxicol ; 53(10): 611-657, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38126124

RESUMO

This analysis updates two previous analyses that evaluated the exposure-response relationships for lung cancer and mesothelioma in chrysotile-exposed cohorts. We reviewed recently published studies, as well as updated information from previous studies. Based on the 16 studies considered for chrysotile (<10% amphibole), we identified the "no-observed adverse effect level" (NOAEL) for lung cancer and/or mesothelioma; it should be noted that smoking or previous or concurrent occupational exposure to amphiboles (if it existed) was not controlled for. NOAEL values ranged from 2.3-<11.5 f/cc-years to 1600-3200 f/cc-years for lung cancer and from 100-<400 f/cc-years to 800-1599 f/cc-years for mesothelioma. The range of best-estimate NOAELs was estimated to be 97-175 f/cc-years for lung cancer and 250-379 f/cc-years for mesothelioma. None of the six cohorts of cement or friction product manufacturing workers exhibited an increased risk at any exposure level, while all but one of the six studies of textile workers reported an increased risk at one or more exposure levels. This is likely because friction and cement workers were exposed to much shorter chrysotile fibers. Only eight cases of peritoneal mesothelioma were reported in all studies on predominantly chrysotile-exposed cohorts combined. This analysis also proposed best-estimate amosite and crocidolite NOAELs for mesothelioma derived by the application of relative potency estimates to the best-estimate chrysotile NOAELs for mesothelioma and validated by epidemiology studies with exposure-response information. The best-estimate amosite and crocidolite NOAELs for mesothelioma were 2-5 f/cc-years and 0.6-1 f/cc-years, respectively. The rate of peritoneal mesothelioma in amosite- and crocidolite-exposed cohorts was between approximately 70- to 100-fold and several-hundred-fold higher than in chrysotile-exposed cohorts, respectively. These findings will help characterize potential worker and consumer health risks associated with historical and current chrysotile, amosite, and crocidolite exposures.


Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Humanos , Asbesto Crocidolita/toxicidade , Asbesto Crocidolita/análise , Asbestos Serpentinas/toxicidade , Amianto Amosita/análise , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/epidemiologia , Nível de Efeito Adverso não Observado , Mesotelioma/induzido quimicamente , Mesotelioma/epidemiologia , Mesotelioma Maligno/induzido quimicamente , Mesotelioma Maligno/complicações , Amiantos Anfibólicos/toxicidade , Amiantos Anfibólicos/análise , Amianto/toxicidade , Amianto/análise
6.
Environ Sci Pollut Res Int ; 30(57): 120844-120862, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37945965

RESUMO

Solar air heaters (SAH) convert solar energy to thermal energy for food processing industries and commercial space heating applications, as solar energy is cost-free. In this experimental study, the thermal performance of the solar air heater has been successively improved using different roughness elements over the absorber. The triangle-shaped wedges in three structures (inline, serpentine, and clustered structure) are investigated in this work. Thermal performance comparison is made with a SAH with a plain absorber. A maximum air temperature rise of 19 °C is observed for the SAH with wedges in a clustered structure. The absorber surface temperature for clustered structured roughness elements is 76.8 °C with an average heat loss coefficient of 4.43 W/m2·K. The useful heat absorption using clustered structure wedges is 33%, 17.9%, and 6.6% higher than the SAH with plain, inline, and serpentine structured wedges. SAH's maximum thermal and exergy efficiency with clustered structured elements is 70.4% and 1.64%. The average thermal efficiency of inline, serpentine, and clustered arrangement is 13.3%, 25.3%, and 35.6% higher than the SAH with a plain absorber. The proposed SAH design shows a sustainability index 1.01, and lower payback periods show economic and environmental viability.


Assuntos
Utensílios Domésticos , Energia Solar , Asbestos Serpentinas , Calefação , Temperatura Alta
7.
Inhal Toxicol ; 35(11-12): 300-307, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37995092

RESUMO

OBJECTIVES: The work shows the effect of counting rules, such as analysis magnification and asbestos fiber dimension to be count (with length ≥5 µm or also asbestos fibers with length <5 µm) in the lung asbestos fiber burden analysis for legal medicine evaluations. METHODS: On the same lung tissue samples, two different analyses were carried out to count any asbestos fibers with length ≥1 µm and with length ≥5 µm. Results of the amphibole burden of the two analyses were compared by linear regression analysis on log10-transformed values. RESULTS: The analysis should be carried out at an appropriate magnification and on samples prepared in such a way as they allow the counting of very fine fibers. If the analysis is limited to the asbestos fibers with length ≥5 µm, there is a high risk of not detecting possible residual chrysotile fiber burden and thinner crocidolite asbestos fibers. CONCLUSIONS: On average we estimated that 1 amphibole fiber with length ≥5 µm corresponds to ∼8 amphibole fibers with length ≥1 µm in the lung. The values of the Helsinki criteria should be updated taking this into account.


Assuntos
Amianto , Neoplasias Pulmonares , Humanos , Amianto/toxicidade , Amianto/análise , Pulmão/química , Amiantos Anfibólicos/toxicidade , Amiantos Anfibólicos/análise , Asbestos Serpentinas/toxicidade , Medicina Legal
8.
Int J Mol Sci ; 24(18)2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37762043

RESUMO

New organic nanostructures were synthesized by introducing 2-methylbenzimidazole (MBI) molecules from a melt, gas phase, or alcoholic solution into nanosized voids of borate porous glasses (PG), nanotubes of chrysotile asbestos (ChA), and mesoporous silica (MS). The incorporation of MBI into borate glasses with different pore sizes is accompanied by the appearance of several phases formed by nanocrystallites which have a MBI crystal structure, but somewhat differ in lattice parameters. The size of some crystallites significantly exceeds the size of nanopores, which indicates the presence of long-scale correlations of the crystal structure. The size of MBI nanocrystallites in ChA was close to the diameter of nanotubes (D ~10 nm), which shows the absence of crystal structure correlations. The XRD pattern of mesoporous silica filled by MBI does not exhibit reflections caused by MBI and a presence of MBI was confirmed only by the analysis of correlation function. The incorporation of MBI molecules into matrices is observed through optical IR absorption spectroscopy (FTIR) and photoluminescence. Introducing MBI in ChA and MS is followed by the appearance of bright green photoluminescence, the spectral structure of which is analogous to MBI crystals but slightly shifted in the blue region, probably due to a quantum-size effect. The influence of MBI inclusion in PG and ChA on the permittivity, dielectric losses, conductivity, and parameters of their hopping conductivity is analyzed.


Assuntos
Nanoporos , Nanotubos , Dióxido de Silício/química , Boratos/química , Asbestos Serpentinas , Nanotubos/química
9.
Am J Ind Med ; 66(10): 904-906, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37528762

RESUMO

BACKGROUND: Four cases of mesothelioma were noted in a workplace of some 110 persons at a tractor dealership between 2006 and 2023. Each worker had a different job title. METHODS: Medical-legal case material was reviewed and abstracted from four cases from the same dealership, all supplied via one law firm. RESULTS: Four mesotheliomas are reported from this single facility that used chrysotile asbestos automotive products. Two of the four cases had no other known exposures to asbestos. DISCUSSION: Automotive products containing chrysotile do appear capable of causing mesothelioma. Job category is not a good surrogate for exposure.


Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Exposição Ocupacional , Humanos , Asbestos Serpentinas , Neoplasias Pulmonares/etiologia , Mesotelioma/etiologia , Exposição Ocupacional/efeitos adversos
10.
J Hazard Mater ; 455: 131590, 2023 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-37178531

RESUMO

The PCM (phase contrast microscopy) method for asbestos counting needs special sample treatments, hence it is time consuming and rather expensive. As an alternative, we implemented a deep learning procedure on images directly acquired from the untreated airborne samples using standard Mixed Cellulose Ester (MCE) filters. Several samples with a mix of chrysotile and crocidolite with different concentration loads have been prepared. Using a 20x objective lens coupled with a backlight illumination system a number of 140 images were collected from these samples, which along with additional 13 highly fibre loaded artificial images constituted the database. About 7500 fibres were manually recognised and annotated following the National Institute for Occupational Safety and Health (NIOSH) fibre counting Method 7400 as input for the training and validation of the model. The best trained model provides a total precision of 0.84 with F1-Score of 0.77 at a confidence of 0.64. A further post-detection refinement to ignore detected fibres < 5 µm in length improves the final precision. This method can be considered as a reliable and competent alternative to conventional PCM.


Assuntos
Amianto , Aprendizado Profundo , Exposição Ocupacional , Estados Unidos , Amianto/toxicidade , Asbestos Serpentinas , Microscopia de Contraste de Fase/métodos , Asbesto Crocidolita
11.
Appl Environ Microbiol ; 89(6): e0204822, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37184266

RESUMO

The Fe content and the morphometry of asbestos are two major factors linked to its toxicity. This study explored the use of microbe-mineral interactions between asbestos (and asbestos-like) minerals and thermophilic chemolithoautotrophic microorganisms as possible mineral dissolution treatments targeting their toxic properties. The removal of Fe from crocidolite was tested through chemolithoautotrophic Fe(III) reduction activities at 60°C. Chrysotile and tremolite-actinolite were tested for dissolution and potential release of elements like Si and Mg through biosilicification processes at 75°C. Our results show that chemolithoautotrophic Fe(III) reduction activities by Deferrisoma palaeochoriense were supported with crocidolite as the sole source of Fe(III) used as a terminal electron acceptor during respiration. Microbial Fe(III) reduction activities resulted in higher Fe release rates from crocidolite in comparison to previous studies on Fe leaching from crocidolite through Fe assimilation activities by soil fungi. Evidence of biosilicification in Thermovibrio ammonificans did not correspond with increased Si and Mg release from chrysotile or tremolite-actinolite dissolution. However, overall Si and Mg release from chrysotile into our experimental medium outmatched previously reported capabilities for Si and Mg release from chrysotile by fungi. Differences in the profiles of elements released from chrysotile and tremolite-actinolite during microbe-mineral experiments with T. ammonificans underscored the relevance of underlying crystallochemical differences in driving mineral dissolution and elemental bioavailability. Experimental studies targeting the interactions between chemolithoautotrophs and asbestos (or asbestos-like) minerals offer new access to the mechanisms behind crystallochemical mineral alterations and their role in the development of tailored asbestos treatments. IMPORTANCE We explored the potential of chemosynthetic microorganisms growing at high temperatures to induce the release of key elements (mainly iron, silicon, and magnesium) involved in the known toxic properties (iron content and fibrous mineral shapes) of asbestos minerals. We show for the first time that the microbial respiration of iron from amphibole asbestos releases some of the iron contained in the mineral while supporting microbial growth. Another microorganism imposed on the two main types of asbestos minerals (serpentines and amphiboles) resulted in distinct elemental release profiles for each type of asbestos during mineral dissolution. Despite evidence of microbially mediated dissolution in all minerals, none of the microorganisms tested disrupted the structure of the asbestos mineral fibers. Further constraints on the relationships between elemental release rates, amount of starting asbestos, reaction volumes, and incubation times will be required to better compare asbestos dissolution treatments studied to date.


Assuntos
Asbestos Serpentinas , Amianto , Asbestos Serpentinas/química , Asbesto Crocidolita , Compostos Férricos , Amianto/química , Minerais , Ferro/química , Bactérias Anaeróbias
12.
Inhal Toxicol ; 35(7-8): 185-200, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37220304

RESUMO

CONTEXT: Excess mesothelioma risk was observed among chrysotile miners and millers in Balangero, Italy. The mineral balangeroite has been identified in an asbestiform habit from the Balangero chrysotile mine (Italy). Previous studies did not contain a detailed description of the fiber dimensions, thus limiting possible approaches to estimating their carcinogenic potential. OBJECTIVES: To reconstruct excess mesothelioma risk based on characteristics of mixed fiber exposure. METHODS: The lengths and widths of particles from a sample of balangeroite were measured by transmission electron microscopy (TEM). Statistical analysis and modeling were applied to assess the toxicological potential of balangeroite. RESULTS: Balangeroite fibers are characterized as asbestiform, with geometric mean length of 10 µm, width of 0.54 µm, aspect ratio of 19, and specific surface area of 13.8 (1/µm). Proximity analysis shows dimensional characteristics of balangeroite close to asbestiform anthophyllite. Modeling estimates the average potency of balangeroite as 0.04% (95% CI 0.0058, 0.16) based on dimensional characteristics and 0.05% (95% CI-0.04, 0.24) based on epidemiological data. The available estimate of the fraction of balangeroite in the Balangero mine is very approximate. There were no data for airborne balangeroite fibers from the Balangero mine and no lung burden data are available. All estimates were performed using weight fractions of balangeroite and chrysotile. However, based on reasonable assumptions, of the seven cases of mesothelioma in the cohort, about three cases (43%) can be attributed to fibrous balangeroite. CONCLUSION: The presence of different types of mineral fibers in aerosolized materials even in small proportions can explain observed cancer risks.


Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Humanos , Asbestos Serpentinas/toxicidade , Fibras Minerais/toxicidade , Carcinógenos/toxicidade , Amiantos Anfibólicos/toxicidade , Mesotelioma/induzido quimicamente , Mesotelioma/epidemiologia , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/epidemiologia , Amianto/análise
13.
Am J Ind Med ; 66(7): 543-553, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36974955

RESUMO

While all forms of asbestos have been determined to be carcinogenic to humans by the International Agency for Research on Cancer (IARC) as well as other authoritative bodies, the relative carcinogenic potency of chrysotile continues to be argued, largely in the context of toxic tort litigation. Relatively few epidemiologic studies have investigated only a single form of asbestos; however, one study that included an asbestos textile plant located in Marshville, North Carolina that processed chrysotile asbestos was used by the United States Environmental Protection Agency (EPA) in 2020 to help inform the agency's chrysotile asbestos risk assessment. During the EPA proceedings toxic tort defense consultants submitted comments to the EPA docket and made public presentations asserting that the Marshville plant had processed amphibole asbestos types and should not be used for the chrysotile risk assessment. A detailed evaluation of defense consultant assertions and supporting information and a full assessment of the available information concerning asbestos types used at the Marshville plant was undertaken. The preponderance of evidence continues to support the conclusion that neither amosite nor crocidolite were likely to have been processed in the Marshville textile plant. Defense consultants' assertions about chrysotile use are not supported by the preponderance of evidence and constitute an example of manipulation of information to cast uncertainty and doubt rather than to seek truth and contribute to the body of scientific evidence.


Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma , Estados Unidos , Humanos , Asbestos Serpentinas/toxicidade , Asbestos Serpentinas/análise , United States Environmental Protection Agency , Amianto/toxicidade , Amianto/análise , Amiantos Anfibólicos/toxicidade , Amiantos Anfibólicos/análise , Asbesto Crocidolita/análise , Asbesto Crocidolita/toxicidade , Medição de Risco , Mesotelioma/epidemiologia
14.
Environ Res ; 230: 114753, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36965802

RESUMO

An earlier meta-analysis of mortality studies of asbestos-exposed worker populations, quantified excess mesothelioma and lung cancer risks in relation to cumulative exposure to the three main commercial asbestos types. The aim of this paper was to update these analyses incorporating new data based on increased follow-up of studies previously included, as well as studies of worker populations exposed predominantly to single fibre types published since the original analysis. Mesothelioma as a percentage of expected mortality due to all causes of death, percentage excess lung cancer and mean cumulative exposure were abstracted from available mortality studies of workers exposed predominantly to single asbestos types. Average excess mesothelioma and lung cancer per unit of cumulative exposure were summarised for groupings of studies by fibre type; models for pleural and peritoneal mesothelioma risk and lung cancer risk in terms of cumulative exposure for the different fibre types were fitted using Poisson regression. The average mesothelioma risks (per cent of total expected mortality) per unit cumulative exposure (f/cc.yr), RM, were 0.51 for crocidolite, 0.12 for amosite, and 0.03 for the Libby mixed amphiboles cohort. Significant heterogeneity was present for cohorts classed as chrysotile, with RM values of 0.01 for chrysotile textiles cohorts and 0.0011 for other chrysotile-exposed cohorts. Average percentage excess lung cancer risks per unit cumulative exposure, RL, were 4.3 for crocidolite and amosite combined, 0.82 for Libby. Very significant heterogeneity was present for chrysotile-exposed cohorts with RL values spanning two orders of magnitude from 0.053 for the Balangero mine to 4.8 for the South Carolina textiles cohort. Best fitting models suggest a non-linear exposure-response in which the peritoneal mesothelioma risk is proportional to approximately the square of cumulative exposure. Pleural mesothelioma and lung cancer risk were proportion to powers of cumulative exposure slightly less than one and slightly higher than one respectively.


Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma , Doenças Profissionais , Exposição Ocupacional , Humanos , Asbestos Serpentinas/toxicidade , Amianto Amosita , Asbesto Crocidolita/toxicidade , Microscopia de Contraste de Fase , Amianto/toxicidade , Mesotelioma/induzido quimicamente , Mesotelioma/epidemiologia , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/epidemiologia , Amiantos Anfibólicos/toxicidade
15.
Water Res ; 231: 119613, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36682237

RESUMO

Iron-based materials for arsenic (As) immobilization in practical groundwater and soil remediation suffer from a low removal capacity and an insufficient long-term stability. Herein, a unique chrysotile-based nanoreactor has been developed by incorporating iron/titanium oxides into the cylindrical cavity of chrysotile (TiFe-Chy), providing sufficient internal reaction sites for As immobilization. Results reveal that the adsorption capacities of TiFe-Chy for As(III) and As(V) are considerably higher than the commonly used amendments, i.e., layered double hydroxide (LDH) and Phoslock®, respectively. More importantly, TiFe-Chy exhibits a strong anti-interference capability of As immobilization in soils compared to those commercial products due to this unique incorporation approach. Fixed-bed leaching experiments indciate that this TiFe-Chy nanoreactor can efficiently decrase the As(III) and As(V) concentrations by 81.8-87.3% within a period of ten years, significantly improving the long-term stability of As immobilization in soils. Life cycle assessment analysis reveals that TiFe-Chy can reduce negative environmental impacts (such as carbon emissions), resulting in a low cost for soils and groundwater remediation. The findings of this work open a new avenue for sustainable heavy metal(loid)s remediation in groundwater and soils.


Assuntos
Arsênio , Recuperação e Remediação Ambiental , Poluentes do Solo , Asbestos Serpentinas , Titânio , Ferro , Solo , Nanotecnologia
16.
Sci Total Environ ; 856(Pt 1): 159061, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36181817

RESUMO

In Calabria (Southern Italy) naturally occurring asbestos (NOA) mainly occurs in the ophiolitic sequences cropping in the Mount Reventino area. The most common type of asbestos detected was the amphibole tremolite; fibrous antigorite and minor chrysotile were also found. The development of asbestos-related diseases depends on, among other things, the morphological characteristics of fibers, length and width, affecting the durability of asbestos fibers in the lung. In this work fifteen lung samples of sheep, goats and wild boars, grazing around the Mount Reventino area were collected and asbestos fibers analysed. Observed fibers (357), of which 97 % were tremolite and 3 % antigorite fibers, were grouped according to species, grazing area and age of the animals. The aim of this work was to highlight any differences among the groupings and to compare our size results with data in literature related to exposed populations. Principal Component Analysis (PCA) highlighted a positive correlation between tremolite fiber length and width and revealed groupings in terms of animal age. The Kruskal-Wallis test showed statistically significant differences between fiber mean widths in young and old animals. 63 % observed asbestiform fibers were longer than 5 µm and 7 % of the fibers were longer than 20 µm (critical fiber length connected to the frustrated phagocytosis by the macrophage). Fibers conforming to the Stanton Hypothesis size (predictor of the carcinogenic potency of fibers) were 1 %. Our size parameters of fibers detected in the animal lungs were in fairly good agreement with literature data for human asbestos exposure to tremolite. These results confirmed that an animal-sentinel system could be used to monitor the natural background of the airborne breathable fibers exposure. In addition, the size correlation of animal-human breathed fibers could be useful to study their potential toxicity. Additional data are necessary for improving the agreement with human exposure data.


Assuntos
Asbestos Serpentinas , Amianto , Humanos , Ovinos , Animais , Asbestos Serpentinas/análise , Asbestos Serpentinas/toxicidade , Amiantos Anfibólicos/análise , Amiantos Anfibólicos/toxicidade , Pulmão
17.
Cancer Sci ; 114(4): 1423-1436, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36541514

RESUMO

Malignant mesothelioma (MM) is still a social burden associated with asbestos exposure. Local iron accumulation thereby represents the major pathogenesis, followed by oxidative DNA strand breaks and genomic alterations in the mesothelium. BRCA1 is a critical component of homologous recombination repair directed to DNA double-stranded breaks, whereas BRCA1 germline mutation is an established risk for breast/ovarian cancer, its role in MM development remains to be elucidated. Murine Brca1 mutant models so far have not reproduced human phenotypes. However, a rat Brca1 mutant model (Mut; L63X/+ ) recently reproduced them at least partially. Here we describe the differential induction of MM in Brca1 mutant rats by intraperitoneal injection of chrysotile or crocidolite. Only Mut males injected with chrysotile revealed a promotional effect on mesothelial carcinogenesis in comparison with wild-type and/or females, with all the MMs Brca1 haploinsufficient. Array-based comparative genomic hybridization of MMs disclosed a greater extent of chromosomal deletions in Brca1 mutants, including Cdkn2a/2b accompanied by Tfr2 amplification, in comparison with wild-type tumors. Mutant MMs indicated iron metabolism dysregulation, such as an increase in catalytic Fe(II) and Ki67-index as well as a decrease in Fe(III) and ferritin expression. Simultaneously, mutant MMs revealed ferroptosis resistance by upregulation of Slc7A11 and Gpx4. At an early carcinogenic stage of 4 weeks, induced Brca1 expression in mesothelial cells was significantly suppressed in chrysotile/Mut in comparison with crocidolite/Mut, whereas significant preference to iron with a decrease in Fe(III) has been already established. In conclusion, chrysotile exposure can be a higher risk for MM in BRCA1 mutant males, considering the rat results.


Assuntos
Amianto , Ferroptose , Neoplasias Pulmonares , Mesotelioma Maligno , Animais , Feminino , Masculino , Ratos , Amianto/toxicidade , Asbesto Crocidolita/toxicidade , Asbestos Serpentinas/toxicidade , Proteína BRCA1/genética , Carcinogênese/genética , Hibridização Genômica Comparativa , DNA , Compostos Férricos/metabolismo , Ferroptose/genética , Haploinsuficiência , Ferro/metabolismo , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , Mesotelioma Maligno/induzido quimicamente , Mesotelioma Maligno/genética
18.
Environ Res ; 230: 115046, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36525994

RESUMO

Exposure to asbestos and asbestos-like minerals has been related to the development of severe lung diseases, including cancer and malignant mesothelioma (MM). A high incidence of non-occupational MM was observed in New Caledonia (France) in people living in proximity of serpentinite outcrops, containing chrysotile and fibrous antigorite. Antigorite is a magnesium silicate, which shares with chrysotile asbestos the chemical formula. To achieve information on antigorite toxicity, we investigated the physico-minero-chemical features relevant for toxicity and cellular effects elicited on murine macrophages (MH-S) and alveolar epithelial cells (A549) of three fibrous antigorites (f-Atg) collected in a Caledonian nickel lateritic ore and subjected to supergene alteration. Field Atg were milled to obtain samples suitable for toxicological studies with a similar particle size distribution. UICC chrysotile (Ctl) and a non-fibrous antigorite (nf-Atg) were used as reference minerals. A high variability in toxicity was observed depending on shape, chemical alteration, and surface reactivity. The antigorites shared with Ctl a similar surface area (16.3, 12.1, 20.3, 13.4, and 15.6 m2/g for f-Atg1, 2, 3, nf-Atg, and Ctl). f-Atg showed different level of pedogenetic weathering (Ni depletion f-Atg1 ≪ f-Atg2 and 3) and contained about 50% of elongated mineral particles, some of which exhibited high aspect ratios (AR > 10 µm, 20%, 26%, 31% for f-Atg1, 2, and 3, respectively). The minerals differed in bio-accessible iron at pH 4.5 (f-Atg1 ≪ f-Atg3, < f-Atg2, nf-Atg < Ctl), and surface reactivity (ROS release in solution, f-Atg1 ≪ f-Atg2, 3, nf-Atg, and Ctl). f-Atg2 and f-Atg3 induced oxidative stress and pro-inflammatory responses, while the less altered, poorly reactive sample (f-Atg1) induced negligible effects, as well nf-Atg. The slow dissolution kinetics observed in simulated body fluids may signal a high biopersistence. Overall, our work revealed a significative cellular toxicity of f-Atg that correlates with fibrous habit and surface reactivity.


Assuntos
Asbestos Serpentinas , Amianto , Humanos , Camundongos , Animais , Asbestos Serpentinas/toxicidade , Nova Caledônia , Amianto/toxicidade , Minerais/toxicidade , Silicatos
19.
Chemosphere ; 313: 137449, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36464018

RESUMO

This study explored a possible destruction of hexachlorobenzene (HCB) as example of persistent organic pollutants (POPs) as well as the dechlorination mechanism by directly using minerals in the soil, such as antigorite, talc and olivine. Compared with a stable quartz phase of SiO2, all three Mg silicate minerals demonstrated certain degrading capacity for HCB with different efficiency order as: antigorite > talc > olivine > SiO2 at 2 h of milling time. Interestingly, olivine exhibited a better performance than antigorite at 4 h of milling time, giving destruction percentage of 92.7% over 89.0% even at high concentrated HCB up to 5% added. Raman and ESR characterizations of the ball milled sample with olivine indicated the formation of amorphous carbon and graphitic carbon, and the occurrence of free radicals was observed to play an important role in dechlorination and carbonization of HCB. The first identified effectiveness of directly using Mg silicate minerals, allowed no addition of active chemicals during the ball milling, therefore avoided the concern over extrinsic contaminations on the soil. Olivine was further utilized to deal with actual contaminated soil and showed unique advantages on application prospects.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Poluentes do Solo/análise , Hexaclorobenzeno/química , Solo/química , Asbestos Serpentinas , Dióxido de Silício , Talco , Minerais , Carbono
20.
Environ Res ; 216(Pt 4): 114664, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36336091

RESUMO

In the present study, we have underpinned the serpentine rock, serpentinized ultramafic soil and rhizosphere's microbial communities, signifying their heavy metals-exposed taxa signatures and functional repertoires in comparison to non-serpentine soils. The results revealed that the serpentine rock embedded soil highlighted the geo-accumulation of higher amount of Cr and Ni impacting soil microbial diversity negatively by metal stress-driven selection. Biolog Ecoplate CLPP defined a restricted spectrum of C-utilization in the higher heavy metal-containing serpentine samples compared to non-serpentine. The linear discriminant analysis (LDA) score identified a higher abundance of Desulfobacterota, Opitutales, and Bacteroidales in low Cr and Ni-stressed non-serpentine-exposed samples. Whereas the abundance of Propionibacteriales and Actinobacteriota were significantly enriched in the serpentine niche. Further, the C, N, S, Fe, and methane biogeochemical cycles linked functional members were identified, and showing higher functional diversity in low Cr and Ni concentration-containing rhizosphere JS-soils. The Pearson correlation coefficient (r) value confirmed the abundance of functional members linked to specific biogeochemical cycle, positively correlated with relevant pathway enrichment. Ultimately, this study highlighted the heavy metal stress within a serpentine setting that could limit the resident microbial community's metabolic diversity and further select the bacteria that could thrive in the serpentine-associated heavy metal-stressed soils. These acclimatized microbes could pave the way for the future applications in the soil conservation and management.


Assuntos
Metais Pesados , Microbiota , Poluentes do Solo , Solo , Poluentes do Solo/análise , Microbiologia do Solo , Metais Pesados/análise , Bactérias/metabolismo , Asbestos Serpentinas/metabolismo
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