Effects of blowing sand fine particles on plasma membrane permeability and fluidity, and intracellular calcium levels of rat alveolar macrophages

Saharan dust induces NLRP3-dependent inflammatory cytokines in an alveolar air-liquid interface co-culture model

BACKGROUND

Epidemiological studies have related desert dust events to increased respiratory morbidity and mortality. Although the Sahara is the largest source of desert dust, Saharan dust (SD) has been barely examined in toxicological studies. Here, we aimed to assess the NLRP3 inflammasome-caspase-1-pathway-dependent pro-inflammatory potency of SD in comparison to crystalline silica (DQ12 quartz) in an advanced air-liquid interface (ALI) co-culture model. Therefore, we exposed ALI co-cultures of alveolar epithelial A549 cells and macrophage-like differentiated THP-1 cells to 10, 21, and 31 µg/cm² SD and DQ12 for 24 h using a Vitrocell Cloud system. Additionally, we exposed ALI co-cultures containing caspase (CASP)1-/- and NLRP3-/- THP-1 cells to SD.

RESULTS

Characterization of nebulized DQ12 and SD revealed that over 90% of agglomerates of both dusts were smaller than 2.5 μm. Characterization of the ALI co-culture model revealed that it produced surfactant protein C and that THP-1 cells remained viable at the ALI. Moreover, wild type, CASP1-/-, and NLRP3-/- THP-1 cells had comparable levels of the surface receptors cluster of differentiation 14 (CD14), toll-like receptor 2 (TLR2), and TLR4. Exposing ALI co-cultures to non-cytotoxic doses of DQ12 and SD did not induce oxidative stress marker gene expression. SD but not DQ12 upregulated gene expressions of interleukin 1 Beta (IL1B), IL6, and IL8 as well as releases of IL-1β, IL-6, IL-8, and tumor necrosis factor α (TNFα). Exposing wild type, CASP1-/-, and NLRP3-/- co-cultures to SD induced IL1B gene expression in all co-cultures whereas IL-1β release was only induced in wild type co-cultures. In CASP1-/- and NLRP3-/- co-cultures, IL-6, IL-8, and TNFα releases were also reduced.

CONCLUSIONS

Since surfactants can decrease the toxicity of poorly soluble particles, the higher potency of SD than DQ12 in this surfactant-producing ALI model emphasizes the importance of readily soluble SD components such as microbial compounds. The higher potency of SD than DQ12 also renders SD a potential alternative particulate positive control for studies addressing acute inflammatory effects. The high pro-inflammatory potency depending on NLRP3, CASP-1, and IL-1β suggests that SD causes acute lung injury which may explain desert dust event-related increased respiratory morbidity and mortality.

Oxidative stress indices induced by industrial and urban PM2.5-bound metals in A549 cells

The detrimental effects of atmospheric fine particulate matter (PM_2.5) on human health are of major global concern. PM_2.5-bound metals are toxic compounds that contribute to cellular damage. To investigate the toxic effects of water-soluble metals on human lung epithelial cells and their bioaccessibility to lung fluid, PM_2.5 samples were collected from both urban and industrial areas in the metropolitan city of Tabriz, Iran. Oxidative stress indices, including proline content, total antioxidant capacity (TAC), cytotoxicity, and DNA damage levels of water-soluble components of PM_2.5, were evaluated. Furthermore, an in vitro test was conducted to assess the bioaccessibility of various PM_2.5-bound metals to the respiratory system using simulated lung fluid. PM_2.5 average concentrations in urban and industrial areas were 83.11 and 97.71 μg/m³, respectively. The cytotoxicity effects of PM_2.5 water-soluble constituents from urban areas were significantly higher than in industrial areas and the IC₅₀ was found to be 96.76 ± 3.34 and 201.31 ± 5.96 μg/mL for urban and industrial PM_2.5 samples, respectively. In addition, higher PM_2.5 concentrations increased the proline content in a concentration-dependent manner in A549 cells, which plays a protective role against oxidative stress and prevents PM_2.5-induced DNA damage. Also, the partial least squares regression revealed that Be, Cd, Co, Ni, and Cr, were significantly correlated with DNA damage and proline accumulation, which caused cell damage through oxidative stress. The results of this study showed that PM_2.5-bound metals in highly polluted metropolitan city caused substantial changes in the cellular proline content, DNA damage levels and cytotoxicity in human lung A549 cells.

Potential hazards associated with interactions between diesel exhaust particulate matter and pulmonary surfactant

Long term exposure to diesel exhaust particulate matter (DEPM) can induce numerous adverse health effects to the respiratory system. Understanding the interaction between DEPM and pulmonary surfactant (PS) can be an essential step toward preliminary evaluation of the impact of DEPM on pulmonary health. Herein, DEPM was explored for its interaction with 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC), the major component of PS. The results indicated that the surface pressure-area (π-A) isotherms of DPPC monolayers shifted toward lower molecular areas and the compression modulus (C_S^-1) reduced in the presence of DEPM. Atomic force microscopy image showed that DEPM can disrupt the ultrastructure of DPPC monolayers along with the direction of lateral compression. In addition, DPPC can in turn condition the surface properties of DEPM, permitting its agglomeration in aqueous media, which was attributed to the adsorption of DEPM to DPPC. Furthermore, the particle-bound polycyclic aromatic hydrocarbons (PAHs) could be desorbed from DEPM by the solubilization of DPPC and it was positively correlated with the hydrophobicity of PAHs. These findings revealed the toxicity of DEPM-associated PAHs and the role of DPPC in facilitating the removal of the inhaled particles, which can provide a new insight into the potential hazards of airborne particles on lung health.

Mechanisms underlying the health effects of desert sand dust

Desertification and climate change indicate a future expansion of the global area of dry land and an increase in the risk of drought. Humans may therefore be at an ever-increasing risk of frequent exposure to, and resultant adverse health effects of desert sand dust. This review appraises a total of 52 experimental studies that have sought to identify mechanisms and intermediate endpoints underlying epidemiological evidence of an impact of desert dust on cardiovascular and respiratory health. Toxicological studies, in main using doses that reflect or at least approach real world exposures during a dust event, have demonstrated that virgin sand dust particles and dust storm particles sampled at remote locations away from the source induce inflammatory lung injury and aggravate allergen-induced nasal and pulmonary eosinophilia. Effects are orchestrated by cytokines, chemokines and antigen-specific immunoglobulin potentially via toll-like receptor/myeloid differentiation factor signaling pathways. Findings suggest that in addition to involvement of adhered chemical and biological pollutants, mineralogical components may also be implicated in the pathogenesis of human respiratory disorders during a dust event. Whilst comparisons with urban particulate matter less than 2.5 μm in diameter (PM2.5) suggest that allergic inflammatory responses are greater for microbial element-rich dust- PM2.5, aerosols generated during dust events appear to have a lower oxidative potential compared to combustion-generated PM2.5 sampled during non-dust periods. In vitro findings suggest that the significant amounts of suspended desert dust during storm periods may provide a platform to intermix with chemicals on its surfaces, thereby increasing the bioreactivity of PM2.5 during dust storm episodes, and that mineral dust surface reactions are an unrecognized source of toxic organic chemicals in the atmosphere, enhancing toxicity of aerosols in urban environments. In summary, the experimental research on desert dust on respiratory endpoints go some way in clarifying the mechanistic effects of atmospheric desert dust on the upper and lower human respiratory system. In doing so, they provide support for biological plausibility of epidemiological associations between this particulate air pollutant and events including exacerbation of asthma, hospitalization for respiratory infections and seasonal allergic rhinitis.

Cytotoxicity induced by fine particulate matter (PM2.5) via mitochondria-mediated apoptosis pathway in rat alveolar macrophages

Although positive associations exist between ambient particulate matter (PM_2.5; diameter ≤ 2.5 μm) and the morbidity and mortality rates for respiratory diseases, the biological mechanisms of the reported health effects are unclear. Considering that alveolar macrophages (AM) are the main cells responsible for phagocytic clearance of xenobiotic particles that reach the airspaces of the lungs, the purpose of this study was to investigate whether PM_2.5 induced AM apoptosis, and investigate its possible mechanisms. Freshly isolated AM from Wistar rats were treated with extracted PM_2.5 at concentrations of 33, 100, or 300 μg/mL for 4 h; thereafter, the cytotoxic effects were evaluated. The results demonstrated that PM_2.5 induced cytotoxicity by decreasing cell viability and increasing lactate dehydrogenase (LDH) levels in AMs. The levels of reactive oxygen species (ROS) and intracellular calcium cations (Ca²⁺) markedly increased in higher PM_2.5 concentration groups. Additionally, the apoptotic ratio increased, and the apoptosis-related proteins BCL2-associated X (Bax), caspase-3, and caspase-9 were upregulated, whereas B cell lymphoma-2 (Bcl-2) protein levels were downregulated following PM_2.5 exposure. Cumulative findings showed that PM_2.5 induced apoptosis in AMs through a mitochondrial-mediated pathway, which indicated that PM_2.5 plays a significant role in lung injury diseases.

Cytotoxicity of the soluble and insoluble fractions of atmospheric fine particulate matter

Inhaled atmospheric fine particulate matter (PM_2.5) includes soluble and insoluble fractions, and each fraction can interact with cells and cause adverse effects. PM_2.5 samples were collected in Jinan, China, and the soluble and insoluble fractions were separated. According to physiochemical characterization, the soluble fraction mainly contains water-soluble ions and organic acids, and the insoluble fraction mainly contains kaolinite, calcium carbonate and some organic carbon. The interaction between PM_2.5 and model cell membranes was examined with a quartz crystal microbalance with dissipation (QCM-D) to quantify PM_2.5 attachment on membranes and membrane disruption. The cytotoxicity of the total PM_2.5 and the soluble and insoluble fractions, was investigated. Negatively charged PM_2.5 can adhere to the positively charged membranes and disrupt them. PM_2.5 also adheres to negatively charged membranes but does not cause membrane rupture. Therefore, electrostatic repulsion does not prevent PM_2.5 attachment, but electrostatic attraction induces remarkable membrane rupture. The human lung epithelial cell line A549 was used for cytotoxicity assessment. The detected membrane leakage, cellular swelling and blebbing indicated a cell necrosis process. Moreover, the insoluble PM_2.5 fraction caused a higher cell mortality and more serious cell membrane damage than the soluble fraction. The levels of reactive oxygen species (ROS) enhanced by the two fractions were not significantly different. The findings provide more information to better understand the mechanism of PM_2.5 cytotoxicity and the effect of PM_2.5 solubility on cytotoxicity.

Effects of PM2.5 on Cardio-Pulmonary Function Injury in Open Manganese Mine Workers

Exposure to fine particulate matter 2.5 (PM_2.5) is associated with adverse health effects, varying by its components. The health-related effects of PM_2.5 exposure from ore mining may be different from those of environment pollution. The aim of this study was to investigate the effects of different concentrations of PM_2.5 exposure on the cardio-pulmonary function of manganese mining workers. A total of 280 dust-exposed workers who were involved in different types of work in an open-pit manganese mine were randomly selected. According to the different concentrations of PM_2.5 in the working environment, the workers were divided into an exposed group and a control group. The electrocardiogram, blood pressure, and multiple lung function parameters of the two groups were measured and analyzed. The PM_2.5 exposed group had significantly lower values in the pulmonary function indexes of forced expiratory volume in one second (FEV1.0), maximum mid expiratory flow (MMEF), peak expiratory flow rate (PEFR), percentage of peak expiratory flow out of the overall expiratory flow volume (PEFR%), forced expiratory flow at 25% and 75% of forced vital capacity (FEF 25, FEF75), forced expiratory flow when 25%, 50%, and 75% of forced vital capacity has been exhaled (FEF25%,FEF50%, FEF75%), and FEV1.0/FVC% (the percentage of the predicted value of forced vital capacity) than the control group (all p < 0.05). Both groups had mild or moderate lung injury, most of which was restrictive ventilatory disorder, and there was significant difference in the prevalence rate of restrictive respiratory dysfunction between the two groups (41.4% vs. 23.6%, p = 0.016). Electrocardiogram (ECG) abnormalities, especially sinus bradycardia, were shown in both groups, but there was no statistical difference of the prevalence rate between the two groups (p > 0.05). Also, no significant difference of the prevalence rate of hypertension was observed between the PM2.5 exposure and control groups (p > 0.05). PM_2.5 exposure was associated with pulmonary function damage of the workers in the open-pit manganese mine, and the major injury was restrictive ventilatory disorder. The early effect of PM_2.5 exposure on the cardiovascular system was uncertain at current exposure levels and exposure time.

Seasonal and spatial variations in the chemical components and the cellular effects of particulate matter collected in Northern China

The health effects of airborne particulate matter (PM) are likely to be strongly influenced by its components. The relationship between the composition of PM and its biological effects has been investigated in vitro/vivo, but more studies are needed to achieve a better understanding of the relationship. Such studies are limited in Northern China, where severe air pollution causes significant health impacts. In this study, we analyzed seasonal PM₁₀ (PM, aerodynamic diameter less than 10μm) samples from five typical cities in Northern China for their physicochemical properties and their in vitro effects on A549 (human lung epithelial cell line) and RAW264.7 (murine monocyte macrophage) cells, including cytotoxicity, oxidative stress and inflammatory effects. Principal component analysis and multiple linear regressions were used to investigate the relationship between the PM components and the cellular responses. The cellular responses of A549 cells were more closely related to the endotoxin content and the levels of polycyclic aromatic hydrocarbons (PAHs) and their derivatives, while the cellular responses of RAW264.7 cells were largely related to PM₁₀-bound metals, and the chalcophile elements (Pb, Cu, Zn, Cd) were more related to the PM-induced oxidative stress, whereas the lithophile and siderophile elements (Al, Fe, Mg, Co, V, Mn, Ca) were more related to PM-induced inflammation and cytotoxicity. As PM compositions changed seasonally, more intense cellular responses were seen when A549 cells were exposed to winter samples that contained higher levels of those components. The autumn and winter samples induced higher levels of oxidative stress in RAW264.7 cells, possibly due to higher contents of chalcophile elements, whereas the spring and/or summer samples were more cytotoxic and proinflammatory, possibly due to higher contents of lithophile and siderophile elements. The study suggests that the evaluation of health impacts induced by air pollution should take into account different physiochemical properties other than the mass concentration, and that public health would benefit greatly from effective, prioritized control of the sources that are the major producers of the central species.

Dispersion of atmospheric fine particulate matters in simulated lung fluid and their effects on model cell membranes

Atmospheric fine particulate matter (PM2.5) was collected to investigate its dispersion in simulated lung fluid (SLF) and its interaction with model cell membranes. Organic acids, NH4(+), SO4(2-) and NO3(-) were detected in PM2.5 soluble fraction, and heavy metals were detected from the total mass. The insoluble fraction contained kaolinite, CaCO3, aliphatic carbons, aromatic rings, carboxyl and hydroxyl groups reflected by the infrared spectra. Proteins dispersed PM2.5 in SLF, resulted in smaller hydrodynamic diameter (dH) and slower sedimentation rate. Conversely, phospholipids increased dH value and accelerated sedimentation rate. Giant unilamellar vesicles (GUVs) and supported lipid bilayers (SLBs) were used as model cell membranes. PM2.5 adhered on and disrupted the membrane containing positively-charged lipids but not the membrane containing neutrally- and negatively-charged lipids, which was monitored by microscopy and a quartz crystal microbalance with dissipation (QCM-D). The cationic sites on membrane were necessary for PM2.5 adhesion, but membrane should be disrupted by the combined action of electrostatic forces and hydrogen bonds between PM2.5 oxygen containing groups and the lipid phosphate groups. Our results specified the roles of proteins and phospholipids in PM2.5 dispersion and transport, highly suggested that the health hazard of PM2.5 was related to the biomolecules in the lung fluid and the particle surface groups.

Traffic-related PM2.5 induces cytosolic [Ca²⁺] increase regulated by Orai1, alters the CaN-NFAT signaling pathway, and affects IL-2 and TNF-α cytoplasmic levels in Jurkat T-cells

The atmospheric particulate matter with a diameter less than or equal to 2.5 um (PM2.5) can result in increased immune system damage or diseases, however, the possible mechanism remains unclear. In this study, we used Jurkat T cells to determine the effects of PM2.5 on T cell-mediated adaptive immune response. Our results indicated that PM2.5 exposure increased intracellular calcium ion concentration [Ca(2+)]. In contrast, cytosolic free Ca(2+) concentration [Ca(2+)]i significantly decreased in Jurkat T cells transfected with Orai1siRNA. In addition, we detected the level of interleukin (IL)-2 and tumor-necrosis factor (TNF)-α as well as other signalling molecules, including calcineurin (CaN) and NFATc2, a gene on 20q13.2 that encodes a member of the nuclear factor of activated T cells (NFAT), in the supernatant of cells exposed to PM2.5. The expression of NFATc2 protein increased in a time-dependent manner after exposure to PM2.5, but the activity of CaN decreased. NFATc2 was not consistent with IL-2 accumulation, thus indicating the involvement of other signals in the suppression of IL-2 accumulation. Our findings demonstrate that PM2.5 exposure in immune cells results in locally increased [Ca(2+)]i generated by Orai1 and CaN-NFAT gene expression, TNF-α and IL-2 cytoplasmic concentrations may be altered.

Ambient air pollution, climate change, and population health in China

As the largest developing country, China has been changing rapidly over the last three decades and its economic expansion is largely driven by the use of fossil fuels, which leads to a dramatic increase in emissions of both ambient air pollutants and greenhouse gases (GHGs). China is now facing the worst air pollution problem in the world, and is also the largest emitter of carbon dioxide. A number of epidemiological studies on air pollution and population health have been conducted in China, using time-series, case-crossover, cross-sectional, cohort, panel or intervention designs. The increased health risks observed among Chinese population are somewhat lower in magnitude, per amount of pollution, than the risks found in developed countries. However, the importance of these increased health risks is greater than that in North America or Europe, because the levels of air pollution in China are very high in general and Chinese population accounts for more than one fourth of the world's totals. Meanwhile, evidence is mounting that climate change has already affected human health directly and indirectly in China, including mortality from extreme weather events; changes in air and water quality; and changes in the ecology of infectious diseases. If China acts to reduce the combustion of fossil fuels and the resultant air pollution, it will reap not only the health benefits associated with improvement of air quality but also the reduced GHG emissions. Consideration of the health impact of air pollution and climate change can help the Chinese government move forward towards sustainable development with appropriate urgency.

The acute and long-term effects of Middle East sand particles on the rat airway following a single intratracheal instillation

Military personnel deployed in the Middle East have emphasized concerns regarding high levels of dust generated from blowing desert sand and the movement of troops and equipment. Airborne particulate matter levels (PM(10); PM < 10 μm) in the region may exceed 1500 μg/m(3), significantly higher than the military exposure guideline (MEG) of 50 μg/m(3). Increases in PM(10) have been linked to a rise in incidences of asthma, obstructive pulmonary disease, lung cancer, and cardiovascular diseases. Male Sprague-Dawley rats received a single intratracheal (IT) instillation of 1, 5, or 10 mg of Middle East PM(10) collected at a military occupied site in Kuwait, silica (positive control), or titanium dioxide (TiO(2); negative control) suspended in 400 μl sterile saline, or saline alone (vehicle control). Twenty-four hours, 3 d, 7 d and 6 mo postexposure (n = 15/group), organs including lung were evaluated for histopathological changes and for particle contaminants. Bronchoalveolar fluid (BALF) was also analyzed for cellular and biochemical parameters, including cytokines and chemokines. Instillation of silica resulted in early, pronounced, sustained inflammation indicated by significant increases in levels of total protein and neutrophils, and activities of lactate dehydrogenase activity and β-glucuronidase activity. Lower magnitude and transient changes using the same markers were observed in animals exposed to TiO(2) and Middle East PM(10). The results suggest that for acute exposures, this Middle East PM(10) is a nuisance-type dust with relatively low toxicity. However, since average deployment of military personnel to the Middle East is 180 d with potential for multiple follow-on tours, chronic exposure studies are needed to fully understand the pulmonary effects associated with Middle East PM exposure.

Induction of oxidative stress and apoptosis by pentachlorophenol in primary cultures of Carassius carassius hepatocytes

Pentachlorophenol (PCP) is a highly toxic contaminant of chlorophenols. Due to its slow and incomplete biodegradation, it can be found in surface, groundwater and in soils. To investigate the role of intracellular calcium and reactive oxygen species in apoptosis induced by PCP in cultured hepatocytes, the primary hepatocytes of Carassius carassius were incubated with different concentrations of PCP at 25 degrees C for 8 h in vitro. Apoptosis was detected by DNA laddering, caspase activation and flow cytometry. The results demonstrated that apoptosis was involved in the cytotoxic effect of PCP, and that PCP-induced apoptosis occurred in a dose-dependent manner. In addition, the induction of apoptosis by PCP was accompanied with Ca2+, Mg2+-ATPase activity decline, intracellular Ca2+ elevation, generation of intracellular reactive oxygen species (ROS), mitochondrial membrane potential (DeltaPsi(m)) disruption and ATP depletion. Concomitantly, there were dose-dependent increases in lipid peroxidation production (MDA) and decreases in glutathione (GSH). These investigations suggest that PCP-induces apoptosis in the cultured hepatocytes by affecting multiple targets, and suggest that [Ca2+]i increase and ROS generation may be involved in apoptosis induction by PCP.

Effects of dust storm PM2.5 on cell proliferation and cell cycle in human lung fibroblasts

Reports on the effects of PM2.5 from dust storm on lung cells are limited. We compared the effects of PM2.5 collected in dust storm days (dust storm PM2.5) with that in sunshiny and non-dust storm days (normal PM2.5) on cell proliferation and cell cycle in human lung fibroblasts. Our results showed that both dust storm and normal PM2.5 had biphasic effects on cell proliferation, namely, stimulated cell proliferation at lower concentrations while inhibited it at higher concentrations. On the contrary, the organic and inorganic extracts from dust storm and normal PM2.5 significantly inhibited the proliferation in human lung fibroblasts at the concentrations corresponding to their mass contents in PM2.5 samples. The flow cytometry showed that the number of cells in G2/M phase increased significantly after treatment with the dust storm and normal PM2.5. The inorganic and organic extracts from PM2.5, however, induced cell arrest in S phase and G0/G1 phase, respectively. It seems that the biphasic effects of both dust storm and normal PM2.5 on cell proliferation may not be related to their inorganic or organic extractable components.

Damage effects of dust storm PM2.5 on DNA in alveolar macrophages and lung cells of rats

The aim of the present study was to investigate in vitro toxicological effects of PM2.5 suspensions, their water-soluble fraction and solvent-extractable organics from dust storm on the viability and DNA of rat alveolar macrophages and in vivo toxicological effects of PM2.5 suspensions on DNA of lung cells of rats. PM2.5 samples from dust storm and normal weather were collected in Baotou city, Inner Mongolia Autonomous Region, and Wuwei city, Gansu Province, China, in March, 2004. DNA damage was detected with single cell gel electrophoresis technique and cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The results showed that: (1) In vitro, PM2.5 suspensions, their water-soluble fraction and solvent-extractable organics from both dust storm and normal weather caused a decrease of the cell viability and an increase of DNA damage of rat alveolar macrophages in a dose-response manner; for both Baotou city and Wuwei city, the samples of normal weather showed higher DNA damage than those of dust storm at the highest treated dosage; for both normal weather PM2.5 and dust storm PM2.5, their solvent-extractable organics showed higher DNA damage than the water-soluble fraction. (2) In vivo, PM2.5 from both dust storm and normal weather caused an increase of DNA damage of rat lung cells in a dose-response manner. (3) Baotou city is one of the heavy industrial cities, while Wuwei is one of agricultural cities in Northwest region of China. The effects induced by normal weather samples in Baotou city slightly higher than those in Wuwei city on DNA damage, though there was no significant difference was found between two cities. These results lead to conclusions that dust storm PM2.5 as well as normal weather PM2.5 could lead to DNA damage and the organic compounds and the insoluble particle-core might be the main contributors to DNA damage. Our results suggest that the risk of health effects may be greater during dust storms because dust storm PM2.5 whose airborne mass were much higher. Further studies are needed to determine the components of dust storm particles that may contribute to the particle toxicity.

Oxidative damage of dust storm fine particles instillation on lungs, hearts and livers of rats

The purpose of this study was to investigate the effects of dust storm fine particles (PM(2.5)) on oxidative damage in lungs, hearts and livers of rats. Wistar rats were randomly divided into treated groups using PM(2.5) at different concentration (1.5, 7.5, 37.5mg/kg) and control groups using saline. After a single intratracheal instillation 24h, rats were sacrificed and activities of Cu,Zn-superoxide dismutase (SOD), levels of glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) were investigated in these three organs of rats. Results show that dust storm PM(2.5) and normal weather PM(2.5) from both Baotou city and Wuwei city caused a dose-dependent decrease of SOD activities and GSH contents in lungs and livers, and a dose-dependent increase of TBARS levels in lungs, hearts and livers of rats as compared to their respective controls. Though the effects induced by normal weather PM(2.5) slightly heavier than dust storm PM(2.5) in both Baotou city and Wuwei city on each examined index, no significant difference was found. Furthermore, no significant difference was observed between the effects induced by dust storm PM(2.5) from Baotou city and that from Wuwei city, or between the effects induced by normal weather PM(2.5) from Baotou city and that from Wuwei city. These results lead to conclusions that both dust storm PM(2.5) and normal weather PM(2.5) could lead to oxidative damage of different disagrees in lungs, hearts and livers, suggesting that the dust storm PM(2.5) whose airborne mass concentrations were much higher should be more harmful. Its toxic effects might be attributed to oxidative damage mediated by pro-oxidant/antioxidant imbalance or excess free radicals. Further work is required to understand the toxicological role of dust storm PM(2.5) on multiple or even all organs in mammals.