Introduction: Chronic air pollution (AirPoll) is associated with accelerated cognitive decline and risk of Alzheimer's disease (AD). Correspondingly, wild-type and AD-transgenic rodents exposed to AirPoll have increased amyloid peptides and behavioral impairments.
Methods: We examined the γ-secretase modulator GSM-15606 for potential AirPoll protection by its attenuating of amyloid beta (Aβ)42 peptide production.
Inflammatory bowel disease (IBD) is an immunologically complex disorder involving genetic, microbial, and environmental risk factors. Its global burden has continued to rise since industrialization, with epidemiological studies suggesting that ambient particulate matter (PM) in air pollution could be a contributing factor. Prior animal studies have shown that oral PM exposure promotes intestinal inflammation in a genetic IBD model and that PM inhalation exposure can increase intestinal levels of pro-inflammatory cytokines.
View Article and Find Full Text PDFThe geopolitical conflict between Russia and Ukraine has disrupted Europe's natural gas supplies, driving up gas prices and leading to a shift towards biomass for residential heating during colder months. This study assessed the consequent air quality and toxicological impacts in Milan, Italy, focusing on fine particulate matter (PM, d < 2.5 μm) emissions.
View Article and Find Full Text PDFBackground: Air pollution particulate matter exposure and chronic cerebral hypoperfusion (CCH) contribute to white matter toxicity through shared mechanisms of neuroinflammation, oxidative stress, and myelin breakdown. Prior studies showed that exposure of mice to joint particulate matter and CCH caused supra-additive injury to corpus callosum white matter. This study examines the role of TLR4 (toll-like receptor 4) signaling in mediating neurotoxicity and myelin damage observed in joint particulate matter and CCH exposures.
View Article and Find Full Text PDFAtmos Environ (1994)
February 2024
In this study, we developed two online monitors for total organic carbon (TOC) and water-soluble organic carbon (WSOC) measurements in fine (d < 2.5μm) and coarse (2.5μm < d < 10μm) particulate matter (PM), respectively.
View Article and Find Full Text PDFExposure to ultrafine particles (UFPs) has been associated with multiple adverse health effects. Inhaled UFPs could reach the gastrointestinal tract and influence the composition of the gut microbiome. We have previously shown that oral ingestion of UFPs alters the gut microbiome and promotes intestinal inflammation in hyperlipidemic Ldlr mice.
View Article and Find Full Text PDFThis study investigates the long-term trends of ambient ultrafine particles (UFPs) and associated airborne pollutants in the Los Angeles Basin from 2007 to 2022, focusing on the indirect effects of regulations on UFP levels. The particle number concentration (PNC) of UFPs was compiled from previous studies in the area, and associated co-pollutant data, including nitrogen oxides (NO), carbon monoxide (CO), elemental carbon (EC), organic carbon (OC), and ozone (O), were obtained from the chemical speciation network (CSN) database. Over the study period, a general decrease was noted in the PNC of UFPs, NO, EC, and OC, except for CO, the concentration trends of which did not exhibit a consistent pattern.
View Article and Find Full Text PDFIn this study, we investigated the seasonal variations, chemical composition, sources, and oxidative potential of ambient PM (particles with a diameter of less than 2.5 μm) in Kuwait City. The sampling campaign was conducted within the premises of Kuwait Institute for Scientific Research from June 2022 to May 2023, covering different seasons throughout the year.
View Article and Find Full Text PDFAm J Respir Crit Care Med
February 2024
Particulate matter ⩽2.5 μm in aerodynamic diameter (PM) is an established cause of lung cancer, but the association with ultrafine particulate matter (UFP; aerodynamic diameter < 0.1 μm) is unclear.
View Article and Find Full Text PDFIn this study, the water-solubility and sources of metals and trace elements in both fine and coarse particulate matter (PM) were investigated in Central Los Angeles. Sampling was performed in the winter, spring, and summer of 2022 at the Particle Instrumentation Unit (PIU) of the University of Southern California located in the proximity of I-110 freeway. Both fine and coarse PM samples were collected using Personal Cascade Impactors (PCIS) and chemically analyzed to determine their water-soluble and water-insoluble metal content.
View Article and Find Full Text PDFLifetime cancer risk characterization of ambient PM-bound carcinogenic metals and polycyclic aromatic hydrocarbons (PAHs) were examined in the cities of Los Angeles (USA), Thessaloniki (Greece) and Milan (Italy), which share similar Mediterranean climates but are different in their urban emission sources and governing air quality regulations. The samples in Milan and Thessaloniki were mostly dominated by biomass burning activities whereas the particles collected in Los Angeles were primary impacted by traffic emissions. We analyzed the ambient PM mass concentration of Cadmium (Cd), Hexavalent Chromium (Cr(VI)), Nickel (Ni), Lead (Pb), as well as 13 PAH compounds in the PM samples, collected during both cold and warm periods at each location.
View Article and Find Full Text PDFAutophagy, a homeostatic mechanism, is crucial in maintaining normal cellular function. Although dysregulation of autophagic processes is recognized in certain diseases, it is unknown how maintenance of cellular homeostasis might be affected by the kinetics of autophagic activity in response to various stimuli. In this study, we assessed those kinetics in lung adenocarcinoma (A549) cells in response to exposure to nanoparticles (NP) and/or Rapamycin.
View Article and Find Full Text PDFAir pollution is associated with risks of dementia and accelerated cognitive decline. Rodent air pollution models have shown white matter vulnerability. This study uses diffusion tensor imaging (DTI) to quantify changes to white matter microstructure and tractography in multiple myelinated regions after exposure to diesel exhaust particulate (DEP).
View Article and Find Full Text PDFIn this study, we developed, optimized, and evaluated in lab and field experiments a wet electrostatic precipitator (ESP) for the collection of ambient PM (particulate matter with aerodynamic diameter < 2.5 μm) into ultrapure water by applying an electrostatic charge to the particles. We operated the wet ESP at different flow rates and voltages to identify the optimal operating conditions.
View Article and Find Full Text PDFBackground: Epidemiological studies have variably linked air pollution to increased risk of Parkinson's disease (PD). However, there is little experimental evidence for this association. Alpha-synuclein (α-syn) propagation plays central roles in PD and glutamate receptor A1 (GluA1) is involved in memory and olfaction function.
View Article and Find Full Text PDFThis study presents the development and evaluation of a high flow rate gelatin cascade impactor (GCI) to collect different PM particle sizes on water-soluble gelatin substrates. The GCI operates at a flow rate of 100 lpm, and consists of two impaction stages, followed by a filter holder to separate particles in the following diameter ranges: >2.5 μm, 0.
View Article and Find Full Text PDFChronic cerebral hypoperfusion (CCH) may amplify the neurotoxicity of nanoscale particulate matter (nPM), resulting in white matter injury. This study characterized the joint effects of nPM (diameter ≤ 200 nm) and CCH secondary to bilateral carotid artery stenosis (BCAS) exposure on neuronal and white matter injury in a murine model. nPM was collected near a highway and re-aerosolized for exposure.
View Article and Find Full Text PDFIn this study we investigated the effectiveness of air purifiers and in-line filters in ventilation systems working simultaneously inside various classrooms at the University of Southern California (USC) main campus. We conducted real-time measurements of particle mass (PM), particle number (PN), and carbon dioxide (CO) concentrations in nine classrooms from September 2021 to January 2022. The measurement campaign was carried out with different configurations of the purifier (i.
View Article and Find Full Text PDFIn this study, we investigated the impact of urban emission sources on the chemical composition of ambient particulate matter (PM) as well as the associated oxidative potential. We collected six sets of PM samples in five urban location sites around the world over long time periods varying from weeks to months, intentionally selected for their PM to be dominated by unique emission sources: (1) PM produced mainly by traffic emissions in central Los Angeles, United States (US); (2) PM dominated by biomass burning in Milan, Italy; (3) PM formed by secondary photochemical reactions thus dominated by secondary aerosols in Athens, Greece; (4) PM emitted by refinery and dust resuspension in Riyadh, Saudi Arabia (SA); (5) PM generated by dust storms in Riyadh, SA, and (6) PM produced mainly by industrial and traffic emissions in Beirut, Lebanon. The PM samples were chemically analyzed and their oxidative potential were quantified by employing the dithiothreitol (DTT) assay.
View Article and Find Full Text PDFSource apportionment analyses are essential tools to determine sources of ambient coarse particles (2.5
Background: Air pollution particulate matter (PM) is strongly associated with risks of accelerated cognitive decline, dementia and Alzheimer's disease. Ambient PM batches have variable neurotoxicity by collection site and season, which limits replicability of findings within and between research groups for analysis of mechanisms and interventions. Diesel exhaust particles (DEP) offer a replicable model that we define in further detail.
View Article and Find Full Text PDFBackground: The mechanisms by which genetic and environmental factors interact to promote asthma remain unclear. Both the IL-4 receptor alpha chain R576 (IL-4RαR576) variant and Notch4 license asthmatic lung inflammation by allergens and ambient pollutant particles by subverting lung regulatory T (T ) cells in an IL-6-dependent manner.
Objective: We examined the interaction between IL-4RαR576 and Notch4 in promoting asthmatic inflammation.
As a primary component of coarse particulate matter (PM), ambient mineral dust has been linked to adverse health effects. Los Angeles, the largest metropolitan urban area of the United States, is impacted by both windblown and localized sources of mineral dust, often internally mixed with black carbon. The estimation of mineral dust concentrations with a high time resolution becomes critical in improving our understanding of its sources and temporal trends.
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