Patients with respiratory diseases in rural areas have been reported to have enhanced responsiveness to ambient particulate matter (PM). In addition to the physical and chemical components, ambient ...PM can contain microorganisms or parts thereof, referred here as BioPM, that can also contribute to the adverse health effects. This study aimed to characterize the microbial composition of BioPM originating from livestock, and to investigate whether these BioPM can trigger the activation of innate receptors and cells. Coarse (PM2.5–10 μm) and fine (PM<2.5 μm) BioPM samples were collected from indoor chicken, pig and goat farms using the versatile aerosol concentration enrichment system (VACES) connected to a Biosampler. The fungal and bacterial communities were assessed with an amplicon based approach using Next Generation Sequencing (NGS). In parallel, HEK-Blue cells expressing different pattern recognition receptors (Toll like receptors (TLR) 2, 3, 4, 5, 7, 8, 9 and NOD 1, 2) and a human monocytic cell line (MM6) were exposed to BioPM samples from these sites. Distinct airborne microbiota profiles associated with the corresponding animal farm were observed. Moreover, the various BioPM contained mainly ligands for TLR2 and TLR4 resulting in a concentration-dependent increase of pro-inflammatory cytokine secreted by MM6 cells. In addition, we show for the first time that only the pig-derived BioPM induced TLR5 activation. These findings suggest that animal farm specific BioPM trigger distinct inflammatory responses, which may contribute to airway diseases in humans.
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•Airborne farm microbiota profiles grouped according to the animal farm.•The BioPM contained mainly ligands for TLR4 resulting in a dose-dependent increase of cytokine secreted by MM6 cells.•Only the pig-derived BioPM induced TLR5 activation•Coarse BioPM induced similar cytokine production by MM6 cells compared to the fine BioPM fraction
Comparative hazard identification of nanomaterials (NMs) can aid in the prioritisation for further toxicity testing. Here, we assessed the acute lung, systemic and liver responses in C57BL/6N mice ...for three NMs to provide a hazard ranking. A silver (Ag), non-functionalised zinc oxide (ZnO) and a triethoxycaprylylsilane functionalised ZnO NM suspended in water with 2% mouse serum were examined 24 hours following a single intratracheal instillation (I.T.). An acute pulmonary inflammation was noted (marked by a polymorphonuclear neutrophil influx) with cell damage (LDH and total protein) in broncho-alveolar lavage fluid (BALF) after administration of both non-functionalised and functionalised ZnO. The latter also induced systemic inflammation measured as an increase in blood neutrophils and a decrease in blood lymphocytes. Exposure to Ag NM was not accompanied by pulmonary inflammation or cytotoxicity, or by systemic inflammation. A decrease in glutathione levels was demonstrated in the liver following exposure to high doses of all three nanomaterials irrespective of any noticeable inflammatory or cytotoxic effects in the lung. By applying benchmark dose (BMD) modeling statistics to compare potencies of the NMs, we rank functionalised ZnO ranked the highest based on the largest number of affected endpoints, as well as the strongest responses observed after 24 hours. The non-functionalised ZnO NM gave an almost similar response, whereas Ag NM did not cause an acute response at similar doses.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Metal-based nanomaterials (MNMs) represent a large category of the engineered nanomaterials, and have been extensively used to enhance the electrical, optical, and magnetic properties of nanoenabled ...consumer products. Inhaled MNMs can penetrate deeply into the peripheral lung at which they first interact with the pulmonary surfactant (PS) lining of alveoli. Here we studied the biophysical inhibitory potential of representative MNMs on a modified natural PS, Infasurf, using a novel in vitro experimental methodology called the constrained drop surfactometry (CDS). It was found that the biophysical inhibitory potential of six MNMs on Infasurf ranks in the order CeO2 > ZnO > TiO2 > Ag > Fe3O4 > ZrO2–CeO2. This rank of in vitro biophysical inhibition is in general agreement with the in vitro and in vivo toxicity of these MNMs. Directly imaging the lateral structure and molecular conformation of the PS film using atomic force microscopy revealed that there exists a correlation between biophysical inhibition of the PS film by the MNMs and their aggregation state at the PS film. Taken together, our study suggests that the nano–bio interactions at the PS film are determined by multiple physicochemical properties of the MNMs, including not only well-studied properties such as their chemical composition and particle size, but also properties such as hydrophobicity, dissolution rate, and aggregation state at the PS film found here. Our study provides novel insight into the understanding of nanotoxicology and metallomics of MNMs.
Introduction: Increased use of nanomaterials has raised concerns about the potential for undesirable human health and environmental effects. Releases into the air may occur and, therefore, the ...inhalation route is of specific interest. Here we tested copper oxide nanoparticles (CuO NPs) after repeated inhalation as hazard data for this material and exposure route is currently lacking for risk assessment.
Methods: Rats were exposed nose-only to a single exposure concentration and by varying the exposure time, different dose levels were obtained (C × T protocol). The dose is expressed as 6 h-concentration equivalents of 0, 0.6, 2.4, 3.3, 6.3, and 13.2 mg/m
3
CuO NPs, with a primary particle size of 10 9.2-14 nm and an MMAD of 1.5 μm.
Results: Twenty-four hours after a 5-d exposure, dose-dependent lung inflammation and cytotoxicity were observed. Histopathological examinations indicated alveolitis, bronchiolitis, vacuolation of the respiratory epithelium, and emphysema in the lung starting at 2.4 mg/m
3
. After a recovery period of 22 d, limited inflammation was still observed, but only at the highest dose of 13.2 mg/m
3
. The olfactory epithelium in the nose degenerated 24 h after exposure to 6.3 and 13.2 mg/m
3
, but this was restored after 22 d. No histopathological changes were detected in the brain, olfactory bulb, spleen, kidney and liver.
Conclusion: A 5-d, 6-h/day exposure equivalent to an aerosol of agglomerated CuO NPs resulted in a dose-dependent toxicity in rats, which almost completely resolved during a 3-week post-exposure period.
Relatively high concentrations of ultrafine particles (UFPs) have been observed around airports, in which aviation and road traffic emissions are the major sources. This raises concerns about the ...potential health impacts of airport UFPs, particularly in comparison to those emitted by road traffic. UFPs mainly derived from aviation or road traffic emissions were collected from a location near a major international airport, Amsterdam-Schiphol airport (AMS), depending on the wind direction, along with UFPs from an aircraft turbine engine at low and full thrust. Human bronchial epithelial cells (Calu-3) model in combination with an air-liquid interface (ALI) cloud system was used for the in vitro exposure to UFPs at low doses ranging from 0.09 to 2.07 μg/cm2. Particle size distribution was measured. Cell viability, cytotoxicity and inflammatory potential (interleukin (IL) 6 and 8 secretion) on Calu-3 cells were assessed after exposure for 24 h. The biological measurements on Calu-3 cells confirm that pro-inflammatory responses still can be activated at the high cell viability (> 80%) and low cytotoxicity. By the Benchmark Dose (BMD) analysis, Airport and Non-Airport (road traffic) UFPs as well as UFPs samples from a turbine engine have similar toxic properties. Our results suggest that UFPs from aviation and road traffic in airport surroundings may have similar adverse effects on public health.
•Airport and road traffic UFPs can activate inflammation in Calu-3 cells.•Airport UFPs exert similar toxicity compared to UFPs from road traffic emission.•ALI condition promotes cellular responses to particles at low exposed dose.
Introduction We evaluated associations between three a-cellular measures of the oxidative potential (OP) of particulate matter (PM) and acute health effects. Methods We exposed 31 volunteers for 5 h ...to ambient air pollution at five locations: an underground train station, two traffic sites, a farm and an urban background site. Each volunteer visited at least three sites. We conducted health measurements before exposure, 2 h after exposure and the next morning. We measured air pollution on site and characterised the OP of PM2.5 and PM10 using three a-cellular assays; dithiotreitol (OPDTT), electron spin resonance (OPESR) and ascorbic acid depletion (OPAA). Results In single-pollutant models, all measures of OP were significantly associated with increases in fractional exhaled nitric oxide and increases in interleukin-6 in nasal lavage 2 h after exposure. These OP associations remained significant after adjustment for co-pollutants when only the four outdoor sites were included, but lost significance when measurements at the underground site were included. Other health end points including lung function and vascular inflammatory and coagulation parameters in blood were not consistently associated with OP. Conclusions We found significant associations between three a-cellular measures of OP of PM and markers of airway and nasal inflammation. However, consistency of these effects in two-pollutant models depended on how measurements at the underground site were considered. Lung function and vascular inflammatory and coagulation parameters in blood were not consistently associated with OP. Our study, therefore, provides limited support for a role of OP in predicting acute health effects of PM in healthy young adults.
Particles and fibres affect human health as a function of their properties such as chemical composition, size and shape but also depending on complex interactions in an organism that occur at various ...levels between particle uptake and target organ responses. While particulate pollution is one of the leading contributors to the global burden of disease, particles are also increasingly used for medical purposes. Over the past decades we have gained considerable experience in how particle properties and particle-bio interactions are linked to human health. This insight is useful for improved risk management in the case of unwanted health effects but also for developing novel medical therapies. The concepts that help us better understand particles' and fibres' risks include the fate of particles in the body; exposure, dosimetry and dose-metrics and the 5 Bs: bioavailability, biopersistence, bioprocessing, biomodification and bioclearance of (nano)particles. This includes the role of the biomolecule corona, immunity and systemic responses, non-specific effects in the lungs and other body parts, particle effects and the developing body, and the link from the natural environment to human health. The importance of these different concepts for the human health risk depends not only on the properties of the particles and fibres, but is also strongly influenced by production, use and disposal scenarios.
Lessons learned from the past can prove helpful for the future of the field, notably for understanding novel particles and fibres and for defining appropriate risk management and governance approaches.
In order to obtain more insight into the tissue distribution, accumulation, and elimination of cerium oxide nanoparticles after inhalation exposure, blood and tissue kinetics were investigated during ...and after a 28-day inhalation study in rats with micro- and nanocerium oxide particles (nominal primary particle size: < 5000, 40, and 5-10 nm). Powder aerosolization resulted in comparable mass median aerodynamic diameter (1.40, 1.17, and 1.02 μm). After single exposure, approximately 10% of the inhaled dose was measured in lung tissue, as was also estimated by a multiple path particle dosimetry model (MPPD). Though small differences in pulmonary deposition efficiencies of cerium oxide were observed, no consistent differences in pulmonary deposition between the micro- and nanoparticles were observed. Each cerium oxide sample was also distributed to tissues other than lung after a single 6-h exposure, such as liver, kidney, and spleen and also brain, testis, and epididymis. No clear particle size-dependent effect on extrapulmonary tissue distribution was observed. Repeated exposure to cerium oxide resulted in significant accumulation of the particles in the (extra)pulmonary tissues. In addition, tissue clearance was shown to be slow, and, overall, insignificant amounts of cerium oxide were eliminated from the body at 48- to 72-h post-exposure. In conclusion, no clear effect of the primary particle size or surface area on pulmonary deposition and extrapulmonary tissue distribution could be demonstrated. This is most likely explained by similar aerodynamic diameter of the cerium oxide particles in air because of the formation of aggregates and irrespective possible differences in surface characteristics. The implications of the accumulation of cerium oxide particles for systemic toxicological effects after repeated chronic exposure via ambient air are significant and require further exploration.
This paper aimed to clarify whether maternal inhalation of engineered nanoparticles (NP) may constitute a hazard to pregnancy and fetal development, primarily based on experimental animal studies of ...NP and air pollution particles. Overall, it is plausible that NP may translocate from the respiratory tract to the placenta and fetus, but also that adverse effects may occur secondarily to maternal inflammatory responses. The limited database describes several organ systems in the offspring to be potentially sensitive to maternal inhalation of particles, but large uncertainties exist about the implications for embryo–fetal development and health later in life. Clearly, the potential for hazard remains to be characterized. Considering the increased production and application of nanomaterials and related consumer products a testing strategy for NP should be established. Due to large gaps in data, significant amounts of groundwork are warranted for a testing strategy to be established on a sound scientific basis.
Exposure to ambient particulate matter (PM) has been associated with adverse cardiovascular effects in epidemiological studies. Current knowledge of independent effects of individual PM ...characteristics remains limited.
Using a semi-experimental design we investigated which PM characteristics were consistently associated with blood biomarkers believed to be predictive of the risk of cardiovascular events. We exposed healthy adult volunteers at 5 different locations chosen to provide PM exposure contrasts with reduced correlations among PM characteristics. Each of the 31 volunteers was exposed for 5 h, exercising intermittently, 3-7 times at different sites from March to October 2009. Extensive on-site exposure characterization included measurements of PM mass and number concentration, elemental- (EC) and organic carbon (OC), trace metals, sulfate, nitrate, and PM oxidative potential (OP). Before and 2 h and 18 h after exposure we measured acute vascular blood biomarkers - C-reactive protein, fibrinogen, platelet counts, von Willebrand Factor, and tissue plasminogen activator/plasminogen activator inhibitor-1 complex. We used two-pollutant models to assess which PM characteristics were most consistently associated with the measured biomarkers.
We found OC, nitrate and sulfate to be most consistently associated with different biomarkers of acute cardiovascular risk. Associations with PM mass concentrations and OP were less consistent, whereas other measured components of the air pollution mixture, including PNC, EC, trace metals and NO2, were not associated with the biomarkers after adjusting for other pollutants.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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