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Insulin resistance (IR) and metabolic disorders are non-pulmonary adverse effects induced by fine particulate matter (PM2.5) exposure. The worldwide pandemic of high fructose sweeteners and fat rich modern diets, also contribute to IR development. We investigated some of the underlying effects of IR, altered biochemical insulin action and Insulin/AKT pathway biomarkers. Male Sprague Dawley rats were subchronically exposed to filtered air, PM2.5, a fructose rich diet (FRD), or PM2.5 + FRD. Exposure to PM2.5 or FRD alone did not induce metabolic changes. However, PM2.5 + FRD induced leptin release, systemic hyperinsulinemia, and Insulin/AKT dysregulation in insulin-sensitive tissues preceded by altered AT1R levels. Histological damage and increased HOMA-IR were also observed from PM2.5 + FRD co-exposure. Our results indicate that the concomitant exposure to a ubiquitous environmental pollutant, such as PM2.5, and a metabolic disease risk factor, a FRD, can contribute to the metabolic disorder pandemic occurring in highly polluted locations.

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.

Mexico displays significant agricultural activity that, in notorious instances unfolds closely associated with undesirable burning practices of crop residues, which could rise climate change and cause adverse effects to human health, due to emission of fine particles (PM2.5). PM2.5 contain organic compounds such as quinones, soluble organic carbon and polycyclic aromatic hydrocarbons (PAHs), which can be associated to carcinogenic and mutagenic diseases and in some cases to cellular oxidative stress. Presently, we carried out simulation burning of crop residues in an open burning to collect PM2.5 samples by an isokinetic methodology (Method 201a of Environmental Protection Agency). The NIOSH870 method was used to quantify organic carbon (OC) and elemental carbon (EC) fractions. PAHs from PM2.5 were extracted and analyzed by gas chromatography-mass spectrometry while the oxidative potential was measured through the dithiothreitol (DTT) consumption and PM2.5 concentration. The results showed that OC fractions concentration are associated with the modified combustion efficiency (MCE). The most abundant fractions were OC1 and OC2. Emission factors of the sum of 18 PAHs (ƩPAHs) showed a large variation between crops; from 0.49 mg kg−1-fuel (for barley) to 9.16 mg kg−1-fuel (for cotton), then, a single emission factor that includes the burning of all crop residues should not be considered, since the emission factor varies according with the type of biomass burned. Whereas PAHs of 4-6 rings (> 97%) were the most abundant, the concentrations of carcinogenic and mutagenic PAHs accounted for 60% of the sum of all PAHs concentrations. Some diagnostic ratios were identified, but these varied between crops. Burning of residues with low combustion efficiencies presented the highest oxidative potential, such as cotton and sorghum. Oxidative potential correlated with OC concentration, but not with PAHs, suggesting the presence of other compounds. [ABSTRACT FROM AUTHOR]

Introduction Exposure to particulate matter (PM) has been associated with cardiorespiratory diseases and adverse birth outcomes, among other end points (Pope and Dockery 2006; Shah and Balkhair 2011; Zanobetti et [...], BACKGROUND: Observed seasonal differences in particulate matter (PM) associations with human health may be due to their composition and to toxicity-related seasonal interactions. OBJECTIVES: We assessed seasonality in PM composition and in vitro PM pro-inflammatory potential using multiple PM samples. METHODS: We collected 90 weekly [PM.sub.10] and [PM.sub.2.5] samples during the rainy-warm and dry-cold seasons in five urban areas with different pollution sources. The elements, polycyclic aromatic hydrocarbons (PAHs), and endotoxins identified in the samples were subjected to principal component analysis (PCA). We tested the potential of the PM to induce tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6) secretion in cultured human monocytes (THP-1), and we modeled pro-inflammatory responses using the component scores. RESULTS: PM composition varied by size and by season. PCA identified two main components that varied by season. Combustion-related constituents (e.g., vanadium, [benzo[a]pyrene, [benzo[a] anthracene) mainly comprised component 1 ([C.sub.1]). Soil-related constituents (e.g., endotoxins, silicon, aluminum) mainly comprised component 2 ([C.sub.2]). PM from the rainy-warm season was high in [C.sub.2]. PM (particularly [PM.sub.2.5]) from the dry-cold season was rich in [C.sub.1]. Elevated levels of cytokine production were associated with [PM.sub.10] and [C.sub.2] (rainy-warm season), whereas reduced levels of cytokine production were associated with [PM.sub.2.5] and [C.sub.1] (dry-cold season). TNFα secretion was increased following exposure to PM with high (vs. low) [C.sub.2] content, but TNFα secretion in response to PM was decreased following exposure to samples containing ≥ 0.1% of [C.sub.1]-related PAHs, regardless of [C.sub.2] content. The results of the IL-6 assays suggested more complex interactions between PM components and particle size. CONCLUSIONS: Variations in PM soil and PAH content underlie seasonal and PM size-related patterns in TNFα secretion. These results suggest that the mixture of components in PM explains some seasonal differences in associations between health outcomes and PM in epidemiologic studies. http://dx.doi.org/10.1289/ehp.1409287

Introduction Inorganic arsenic (iAs) is naturally occurring and ubiquitous in the environment. In most populations, drinking water is the main source of human exposure. Long-term exposure to iAs has been [...], BACKGROUND: Arsenic exposure is a risk factor for atherosclerosis in adults, but there is little information on arsenic and early risk biomarkers for atherosclerosis in children. Carotid intima-media thickness (cIMT) is an indicator of subclinical atherosclerotic burden that has been associated with plasma asymmetric dimethylarginine (ADMA), a predictor of cardiovascular disease risk. OBJECTIYES: The aim of this study was to investigate associations of arsenic exposure with cIMT, ADMA, and endothelial adhesion molecules [soluble intercellular cell adhesion molecule-1 (sICAM-1); soluble vascular cell adhesion molecule-1 (sVCAM-1)] in children who had been exposed to environmental inorganic arsenic (iAs). METHODS: We conducted a cross-sectional study in 199 children 3-14 years of age who were residents of Zimapan, Mexico. We evaluated cIMT using ultrasonography, and plasma lipid profiles by standard methods. We analyzed ADMA, sICAM-1, and sVCAM-1 by ELISA, and measured the concentrations of total speciated arsenic (tAs) in urine using hydride generation cryotrapping atomic absorption spectrometry. RESULTS: In the multiple linear regression model for cIMT, tAs categories were positively associated with cIMT increase. The estimated cIMT diameter was greater in 35- to 70-ng/mL and > 70-ng/mL groups (0.035 mm and 0.058 mm per 1-ng/mL increase in urinary tAs, respectively), compared with the < 35-ng/mL group. In addition to tAs level, plasma ADMA was a significant predictor of cIMT. In the adjusted regression model, cIMT, percent iAs, and plasma sVCAM-1 were significant predictors of ADMA levels (e.g., 0.419-umol/L increase in ADMA per 1-mm increase in cIMT). CONCLUSIONS: Arsenic exposure and plasma ADMA levels were positively associated with cIMT in a population of Mexican children with environmental arsenic exposure through drinking water. http://dx.doi.org/10.1289/ehp.1205994