Inhalation Toxicology最新文献

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.

Objectives: Oxidative stress (OS) and oxidative DNA damage accruing from chronic exposure to wood dust have been implicated in the development of chronic lung conditions among woodworkers. Indices of OS, inflammation, oxidative DNA damage and lung function in relation to duration of exposure to wood dust were assessed in woodworkers to determine their possible utility as risk evaluation indices for chronic lung conditions.

Methods: Ninety participants comprising 30 active woodworkers, 30 passive woodworkers, and 30 controls were enrolled into this cross-sectional study. The total plasma peroxides, total antioxidant capacity (TAC), oxidative stress index (OSI), malondialdehyde (MDA), reduced glutathione, nitric oxide, high sensitivity C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and peak expiratory flow rate (PEFR) were determined in all participants.

Results: Woodworkers had lower PEFR, TAC, and higher malondialdehyde, OSI, hs-CRP, and 8-OHdG compared to controls (p < 0.05). Active woodworkers had higher malondialdehyde, 8-OHdG, and hs-CRP compared to passive woodworkers (p < 0.05). Increasing duration of exposure to wood dust is associated with higher malondialdehyde, hs-CRP, and 8-OHdG in active woodworkers (p < 0.05) and higher 8-OHdG and hs-CRP in passive woodworkers (p < 0.05). Negative correlation was observed between hs-CRP and TAC (r=-0.367, p = 0.048) in active workers.

Conclusion: The association of exposure to wood dust with elevated indices of inflammation, OS, lipid peroxidation, oxidative DNA damage, and reduction in antioxidants and peak expiratory flow rate; and the concomitant increase in oxidative DNA damage and inflammation with increasing duration of exposure suggest that these indices may be useful in predicting woodworkers at risk of development of chronic lung conditions.

Purpose: As consequences of industrial processes, air pollution has led to increased cardiovascular diseases resulting in mortality. However, there are few pieces of evidence expressing physical fitness and gender impacts in such environments. Regarding long-term exposure to air pollution, this study aimed to determine the effect of physical fitness on post-exercise cardiac parasympathetic reactivation among healthy males and females.

Methods: 120 individuals (46 ± 5 years) participated and were categorized into two main groups (n = 60; EG, CG); (1) The experimental group included individuals living in an air-polluted environment; (2) The control group included the citizens of a clean air region; and two physical fitness status subgroups (n = 30; active vs. sedentary) across both sexes. The heart rate (HR) changes at different timing after performing an incremental exercise, and T30 were calculated as metrics of cardiac parasympathetic reactivation.

Results: The heart rate recovery values were substantially lower in EG in comparison to CG (p < 0.001) at different timing, while, T30 was significantly greater in residents of the air-polluted city compared to CG (p < 0.001). As for heart rate recovery at the 5th minute, the values were significantly lower in the steady-female group in comparison to the active females living in the air-polluted city (p < 0.01).

Conclusion: Based on our findings, although physical fitness modifies the adverse impacts of long-term exposure to air pollution on post-exercise cardio-parasympathetic reactivation, it appears to parallel the acute/intermediate recovery of the thermoregulatory and vascular systems, among both sexes, it does not prevent them.

Alterations in dopaminergic transmission are associated with neurological disorders, such as depression, autism, and Parkinson's disease. Exposure of rats to ambient fine (FP) or ultrafine (UFP) particles induces oxidative and inflammatory responses in the striatum, a neuronal nucleus with dense dopaminergic innervation and critically involved in the control of motor activity.Objectives: We used an ex vivo system to evaluate the effect of in vivo inhalation exposure to FP and UFP on motor activity and dopaminergic transmission.Materials and Methods: Male adult Wistar rats were exposed to FP, UFP, or filtered air for 8 weeks (subchronic exposure; 5 h/day, 5 days/week) in a particle concentrator. Motor activity was evaluated using the open-field test. Uptake and release of [³H]-dopamine were assessed in striatal synaptosomes, and dopamine D₂ receptor (D₂R) affinity for dopamine was evaluated by the displacement of [³H]-spiperone binding to striatal membranes.Results: Exposure to FP or UFP significantly reduced spontaneous motor activity (ambulatory distance: FP -25%, UFP -32%; ambulatory time: FP -24%, UFP -22%; ambulatory episodes: FP -22%, UFP -30%), decreased [³H]-dopamine uptake (FP -18%, UFP -24%), and increased, although not significantly, [³H]-dopamine release (113.3 ± 16.3 and 138.6 ± 17.3%). Neither FP nor UFP exposure affected D₂R density or affinity for dopamine.Conclusions: These results indicate that exposure to ambient particulate matter reduces locomotion in rats, which could be related to altered striatal dopaminergic transmission: UFP was more potent than FP. Our results contribute to the evidence linking environmental factors to changes in brain function that could turn into neurological and psychiatric disorders.HIGHLIGHTSYoung adult rats were exposed to fine (FP) or ultrafine (UFP) particles for 40 days.Exposure to FP or UFP reduced motor activity.Exposure to FP or UFP reduced dopamine uptake by striatal synaptosomes.Neither D₂R density or affinity for dopamine was affected by FP or UFP.UFP was more potent than FP to exert the effects reported.

Objective: The air quality index (AQI) forecasts are one of the most important aspects of improving urban public health and enabling society to remain sustainable despite the effects of air pollution. Pollution control organizations deploy ground stations to collect information about air pollutants. Establishing a ground station all-around is not feasible due to the cost involved. As an alternative, satellite-captured data can be utilized for AQI assessment. This study explores the changes in AQI during various COVID-19 lockdowns in India utilizing satellite data. Furthermore, it addresses the effectiveness of state-of-the-art deep learning and statistical approaches for forecasting short-term AQI.

Materials and methods: Google Earth Engine (GEE) has been utilized to capture the data for the study. The satellite data has been authenticated against ground station data utilizing the beta distribution test before being incorporated into the study. The AQI forecasting has been explored using state-of-the-art statistical and deep learning approaches like VAR, Holt-Winter, and LSTM variants (stacked, bi-directional, and vanilla).

Results: AQI ranged from 100 to 300, from moderately polluted to very poor during the study period. The maximum reduction was recorded during the complete lockdown period in the year 2020. Short-term AQI forecasting with Holt-Winter was more accurate than other models with the lowest MAPE scores.

Conclusions: Based on our findings, air pollution is clearly a threat in the studied locations, and it is important for all stakeholders to work together to reduce it. The level of air pollutants dropped substantially during the different lockdowns.