Primary Air Research Articles

Water Wall Tubes’ High Temperature Corrosion Root Cause Investigation: A 300 MW Level Boiler Case

High temperature corrosion poses a great threat to boiler water wall safe operation. To investigate the corrosion root cause, a 300 MW level boiler water wall high temperature H2S corrosion case was reported. The typical hydrogen sulfide H2S corrosion feature was large amounts of sulfur which could be found in the cut down sample tube corrosion layer, with a thickness of 482 μm. In addition, huge amounts of lead (Pb) could be found in the corrosion layer, which resulted from the lead sulfide (PbS) deposition when the high temperature flue gas condensed at the water wall tubes. Meanwhile, the sulfur in the corrosion layer was closely related to the H2S concentration in the water wall ambience. The related ambience test showed that the H2S could achieve up to 1000 ppm when the boiler was in operation, far larger than the suggested reference value of 100 ppm. Hence, the overlarge H2S concentration was a vital factor for the tube corrosion. To further investigate the reason why the H2S was kept in such high concentration in the boiler long term operation, and the reasons for the over-high sulfur content in the coal and the over-large diameter of the imaginary circle of primary air (DICPA), two factors were obtained. The peak sulfur content reached 2.5% and the suggested sulfur content was below 1%. The DICPA was so large (1580 mm) that the pulverized coal easily scoured the water wall tubes, which would boost the thinning process of the tubes. To relieve the high temperature corrosion, improve the coal qualities, decrease the DICPA, adjust the operation diameter and adopt a coating technology four measures were suggested.

Cooling performance and optimization of a tubular indirect evaporative cooler based on response surface methodology

To optimize the cooling effectiveness of the tubular indirect evaporative cooler (TIEC), an experimental design was conducted using the response surface methodology (RSM). In this work, the wet-bulb effectiveness was selected as the response value, while the influencing factors included six operation parameters, namely, the spray water flow rate (Qw), secondary-to-primary air flow rate ratio (Rsp), primary air resistance (R1), secondary air resistance (R2), inlet air dry bulb temperature (tg1) and air relative humidity (RH). The operation conditions of a TIEC with a tube diameter of 10 mm were optimized. The second-order model fitting of the RSM was used to obtain the polynomial regression equation between the wet-bulb effectiveness and each factor. The wet-bulb effectiveness can be achieved up to 78 % under the optimized conditions with Qw of 1.2 m3/h, Rsp of 0.5, R1 of 89 Pa, R2 of 100 Pa, tg1 of 17.3 °C, and RH of 79.6 %.

Impact of Primary Air Separation in a Grate Furnace on the Resulting Combustion Products

When burning fuel in grate furnaces, supplying the right amount of air to them is as important as the method of air supply. In a furnace with a fixed grate, the supply method of primary air is determined by the distribution of the supplied air stream over time, and in a furnace with a movable grate, the said method involves the distribution of the stream along the active length of the grate. The need to account for air distribution is attributable to complex processes that occur during the combustion process. The paper describes experimental studies aimed at determining the influence of the distribution of the supplied primary air on the emission of CO2, CO, SO2, NOx, and on the content of combustible parts in the slag. In all cases, the total amount of primary air supplied to the process as well as other process control parameters was identical, and only the distribution of primary air was different. The paper proposes the use of a generalized function to describe the distribution of air, defined by its total demand and the relative time R that fuel remains on the grate until the maximum air stream is obtained. The quantity R was accepted at the value ranging from 1/6 to 2/3. With the rise of R, the emissions of CO2, CO, and SO2 increased by 53%, 125%, and 27%, respectively, and the emissions of NOx and the share of combustibles in the slag decreased by 12% and 79%, respectively.

Temperature, pressure, and adsorption dependent redox potentials: III. Processes of CO conversion to value‐added compounds

AbstractCarbon monoxide (CO) is a primary air pollutant and a poisonous species for human beings, animals, and some catalytic reactions. Meanwhile, CO is also a versatile feedstock in the chemical industry to produce high‐value chemicals and clean fuels, which has stimulated extensive research interests in exploiting efficient CO conversion processes. Redox potential is a key thermodynamic quantity in these processes whereas only standard reduction potentials at 25°C and 1 atm are currently available. Herein, it is the first time to report the effects of temperature (0–1000°C), pressure (1–100 atm), and adsorption on the redox potentials of 18 CO conversion reactions to form carbon dioxide, methane, straight‐chain alkanes (ethane, propane, and butane), light olefins (ethylene, propylene, and butylene), benzene, alcohols, aldehydes, acids, and dimethyl ether, based on theoretical calculations. It was noticed that gas‐phase, aqueous‐phase, and adsorption‐state redox potentials decrease with increasing temperature at an increased rate while they show different responses to pressure change. Namely, gas‐phase and most aqueous‐phase redox potentials increase with pressure at a gradually declined rate, while adsorption‐state redox potentials are not influenced by pressure. Most importantly, the significant differences up to 2.06 V under varied conditions highlight the necessity of applying operando redox potentials for CO conversion reactions.

Modelling of atmospheric water generation using desiccant coated heat exchangers: A parametric study

Water scarcity is a significant issue in developing countries and remote locations, however, atmospheric water vapour is a widely available and yet underutilised water reservoir. Desiccant coated heat exchangers are a potential sorption reactor for multicyclic atmospheric water generation due to the enhanced heat and mass transfer to the desiccant. This study utilised a transient one-dimensional mathematical model for a plate-fin desiccant coated heat exchanger and adapted the model for atmospheric water generation. From this, a heat and mass transfer analysis and parametric study were conducted to determine the effect of the operational and geometric parameters on the specific water production and specific energy consumption. The heat and mass transfer analysis found that the coating at the inlet and outlet regions of the channels were underutilised. The parametric study found that the adsorption and desorption cycle times should be optimised independently, the primary air velocity should be high during adsorption and low during desorption, and secondary channel cooling during adsorption did not significantly improve performance. The highest specific water production and the lowest specific energy consumption recorded in this study were 5.8 L kg−1 day−1 and 7.7 MJ L-1 respectively. The recorded specific water production values were higher than most desiccant based atmospheric water generators in the literature. However, the performance was significantly reduced at higher ambient temperatures.

Simulation and Experimental Study on the Low NOx Combustion of 35 Kw Biomass Boiler with Air Staging

In the present research, numerical simulations and combustion experiments were carried out using a 35 kW biomass low nitrogen combustion furnace. For this purpose, the boiler structure and fluid area in the furnace were modeled. Subsequently, the grid was divided and the parameters such as speed and pressure were set using Gambit. Then, the model was introduced into Fluent in order to simulate the combustion process and for flow field output and analysis. By analyzing the distribution and changes in temperature field, velocity field, and NOx concentration field under different air supply schemes, and performing low nitrogen combustion experiments, the influence of different air supply schemes on fuel combustion and NOx emission was determined. Through the mutual verification of simulation and experimental research, the optimal air distribution scheme was obtained. The results showed that: without the air staged combustion, combustible gas and air were not properly mixed. As a result, the loss of mechanical incomplete combustion occurred. Under air-staged combustion, the addition of the secondary air reduced the “chimney flow” phenomenon in the furnace to a certain extent. The combustible gas and air were mixed more adequately and the reaction rate and efficiency significantly increased. In addition, with the introduction of the secondary air, the air and the flue gas in the furnace were more efficiently mixed. Moreover, the temperature in the upper combustion area of the furnace decreased by 300–500 K, which slowed down the rate of nitrogen oxides production. This effect was intensified when the proportion of the secondary air increased. The status of the combustion process and changes in the concentration of NOx in the flue gas were compared and analyzed under various working conditions. Data indicated that the optimal air distribution scheme was that with 70% of the primary air and 30% of the secondary air. In this case, the NOx emissions were 27% lower than those without the air staged combustion.

Experimental investigation on combustion characteristics of novel preheated air swirl burner operating on the heavy oil fired furnace for reducing NOx emission

ABSTRACT This paper presents an experimental study carried out to evaluate the influence of air swirl vane angles on pollutants in a heavy oil fuel fired furnace with a recuperator. A novel burner system with a range of concentric air swirl generators (vane angles of 15°, 20°, 30°, 45°, 60°, and 90°) was ultimately incorporated to the combustion chamber of a 250 kg crucible furnace. This study examined the thermal efficiency and the polluting emission parameters of CO2, HC, CO, and NOx. According to the results, preheated air-fuel and air swirl generators with vane angles of 45° and 30° emit the least HC and CO, whereas air swirl vane angles of 90° emit the most. A preheated primary air swirl vane angle of 45° results in the lowest NOx emission (25 ppm) value. Furthermore, with larger air swirl vane angles of 45° results in increased temperature and premixed combustion, as well as a raise in NOx emission. To ensure accurate airflow for complete combustion, secondary air entry area kept twice the primary air entry area in the novel burner. The results showed that when the temperature of the preheated primary and secondary air and heavy oil fuel combination increased, so did the mean effective temperature of the combustion gases. Conversely, when the vane angle is reduced and no preheated air-fuel combination is present, the mean temperature of the combustion gas drops dramatically.

Elemental chemical characterization and morphology of PM10 using SEM/EDS in air quality monitoring station filters in Poza Rica, Veracruz, Mexico

Air quality has been a global problem for several decades and has had several approaches for its mitigation, analysis and quantification. There are several ways and methods to quantify primary and secondary air pollutants. Therefore, the objective of this research was to determine, through SEM-EDS analysis, the elemental chemical characterization and morphology of the compounds present in the tapes of PM10 BAM (Beta Attenuation Mass Monitor) equipment from air quality monitoring campaigns in the city of Poza. Rica, Veracruz in Mexico. The methodology consisted of collecting filter tapes from the air quality monitoring stations used in the evaluation period, sampling and analysis was performed by the SEM/EDS scanning electron microscopy technique. The results allowed identifying in the samples the elemental chemical characterization and morphology of the particles retained in them.

Operational optimization of air staging and flue gas recirculation for NOx reduction in biomass circulating fluidized bed combustion

Cost effective nitrogen oxide (NOx) reduction technology is crucial for industries and power plants owing to the stringent environmental regulations to which industries and power plants must adhere. Herein, the aim was to optimize the operational conditions for NOx reduction in forest biomass using circulating fluidized bed combustion (CFBC) combined with air staging and flue gas recirculation (FGR). The profiles of temperature and solid suspension density in the combustor, NO and CO emissions, fuel-N conversion, slagging and fouling tendencies, and combustion efficiency were comprehensively observed during combustion. The main operating parameters are the FGR ratios, optimal ratios of air staging [Primary air (PA):Secondary air (SA):Tertiary air (TA)] and FGR, and supply height of TA in the combustor. Notably, under the optimal operational conditions (air staging ratio; PA:SA:TA = 70:10:30, FGR ratio; 8%, and TA supply height; 8.1 m), the NO and CO emissions were simultaneously reduced to 25.9% and 18.2%, respectively, compared with that for the base scenario which excluded air staging and FGR. Furthermore, a high combustion efficiency of 99.72% was maintained without any ash-related problems at well-controlled bed temperatures owing to the constant solid circulation afforded by FGR. A thorough analysis of the this literature has been performed to ensure that the commercialization of the combination of air staging and FGR in biomass CFBC plants is feasible, which could be an inexpensive option for NO reduction.

Improving combustion and lowering NO emissions of an industrial coal swirl burner by optimizing its nozzle structure

• Simulation and comparison are conducted for the burner before and after optimization. • Entrained effect of secondary air on primary air is enhanced with retrofitting ISACS. • Retrofitting ISACS has significant effects on the combustion characteristics. • Optimized burner performs better in NOx reduction, flame stability and burnout rate. To accommodate rapidly growing but highly variable renewable power in the grid and large variations in power demand, coal-fired power plants need to be flexibly operated through fast and wide load changes, still with high efficiency and reliability and low emissions. Towards reliable implementation in a power plant under flexible operation, this paper comprehensively investigates the improvement of an industrial low-NO x swirl burner via numerical simulation and various field tests. Burner aerodynamics, which play a vital role in its performance, are largely affected by the burner nozzle structure. For the low-NO x swirl burner under study, the inner secondary air cone structure is found to have the most significant impact on the burner aerodynamics and the combustion performance. For the coal fired in the power plant, the newly designed inner secondary air cone structure, which is a kind of an extended smooth diverging duct, greatly facilitates the entrainment of the primary air into the surrounding swirl secondary air stream and largely enhances lateral mixing. A large recirculation zone is formed between the primary air and the inner secondary air stream, stabilizing ignition and combustion under flexible operation conditions. This is particularly important for low-load operation. Comparatively, reducing the secondary air duct area for a higher axial momentum of the secondary air stream and adding a new particle separation ring for more dispersed particle distribution are found to have a minor impact on the burner aerodynamics. The optimized burner nozzle structure via numerical simulation has been finally adopted by the power plant for the burner retrofit, on which various field tests have been performed on the retrofitted burner. The tests show that the nozzle structure optimization remarkably improves the burner performance, which is also consistent with the numerical prediction. This study also provides useful guidance for optimizing the swirl burners of the similar type.

Mixing Characteristics and Flow Fields Optimization of Primary Air for Coal Mill

This paper mainly focuses on the problems of inaccurate measurement of the primary air flow rate in a coal-fired power plant. The feasibility of improving the uniformity of flow fields and temperature fields by installing double-layer arch cool air distributor and mixed flow matrix was analyzed by the method of numerical simulation. The results show that, the relative standard deviation of the wind speed measurement section of optimization model decreased from 18.7%~18.4% to 9%~9.1%, compared with the original model. Similarly, the relative standard deviation of temperature measurement section also decreased from 15%~14.6% to 1.3%~1.4%. The study suggests that this mixed flow fields equalization solution can effectively enhance the mixing of cool and hot primary air, and can improve the uniformity of the mixed air flow fields, thereby improving the accuracy and reliability of primary air measurement.

Numerical simulation of pulverized coal combustion in a rotary kiln under O2/CO2 atmosphere

The cement industry is the second largest source of global man-made CO2 emissions after the power industry, and the adoption of O2/CO2 combustion technology for cement kilns is of great significance in reducing CO2 emissions. In this paper, the effects of pulverized coal mixed air combustion and pulverized coal mixed O2/CO2 combustion on the velocity field, temperature field, CO2 and NOx concentration distribution in rotary kiln were investigated by CFD technique. The results showed that there is no difference in the velocity distribution between the two atmospheres, and the speed difference between the primary and secondary air creates a re-circulation zone near the burner. The O2/CO2 atmosphere combustion decreased the maximum temperature, but improved the uniformity of the temperature field. The pulverized coal burnout rate under O2/CO2 atmosphere decreased by 3.55% compared to O2/N2 atmosphere. The mole fraction of CO2 at the rotary kiln outlet is 0.08 and 0.93 for O2/N2 and O2/CO2 combustion atmospheres, respectively. It is easier to achieve CO2 aggregation and capture under O2/CO2 atmosphere than under O2/N2. The NOx concentration at O2/CO2 is approximately one half of that at O2/N2, which can save the investment on denitrification equipment. The simulation results reasonably agree with the measured data. The findings of this work will provide a reference for the generalization and application of the O2/CO2 flue gas cycle calcinating cement technology.

Research on the Influence of Valve Sensor Fault Based on Simulation

In the practical application of indoor air quality assurance system, it is difficult to detect the fault of air valves, CO2 sensors and other components, resulting in substandard air quality and increased energy consumption. In this paper, 16 fault conditions and 1 no fault condition were simulated by Simulink simulation software for primary return air conditioning system in summer, and a typical indoor air quality assurance system simulation fault characteristic table was obtained. It is found that PM2.5 sensor fault mainly affects indoor PM2.5 purification speed. The fault of a CO2 sensor affects indoor CO2 dilution and system energy consumption. Small resistance of return air valve increases system energy consumption. Small resistance of supply air valve, exhaust air valve and return air valve decreases the system's ability to control indoor pollutants.

Causes and Consequences of Preterm Birth, A Systematic Review

To systematically review the potential causes and possible effects of preterm birth [<37 weeks gestational duration]. We searched PubMed, google scholar, clinicaltrials.gov and science direct for English language articles published from 2004 to march 2021. All kinds of study schemes were considered acceptable, comprising case –control, cohort studies, experimental and cross- sectional studies. Significant evidences indicate that social stress, elevated cadmium exposure, genomic variations, vitamin D deficiency, pre-conception hepatitis B infection, declined vaginal microbial community, intrauterine infection, reduction in cervical consistency index, strong exposure of creatinine corrected thallium, systemic autoimmune diseases, ozone, primary traffic air pollutants, road traffic noise, potential exposure of arsenic, HIV exposure, maternal thyroid dysfunction, maternal plasma protein level and COVID-19 exposure in pregnant females are the major risk factors for PTBs. Results of earlier investigations indicated prominent risk of insulin resistance, hypertension, neurological defects, heart failure, Chronic kidney disease, Lung function impairment, lower birth weight, thalamocortical system defects, cancer, altered cardiac phenotype and cardio metabolic diseases in survivors of preterm births. This review will help clinicians to isolate the fundamental etiology and to proactively identify, cope and improve outcomes of at-risk pregnancies.

Performance characterization of M-cycle indirect evaporative cooler and heat recovery ventilator for commercial buildings – Experiments and model

Evaporative cooling systems in buildings can dramatically reduce greenhouse gas emissions due to their low energy consumption, lack of ecologically harmful refrigerants and their diverse applications. Indirect evaporative cooling (IEC) uses water in the secondary air stream to cool the primary air without adding humidity to the indoor environment. The Maisotsenko Cycle (M−Cycle) design of an IEC has the potential to approach dew-point on the primary air by pre-cooling the secondary air stream before extracting heat in cross-flow with the primary air. Separately, a variety of technologies exist for energy recovery in commercial buildings to pre-condition ventilation air. In this study a M−cycle heat and mass exchanger was used as a heat recovery ventilator (HRV) to recover energy from the exhaust air stream during winter and as an IEC during summer to cool the ventilation air. Experiments were performed by operating the full-size IEC/HRV system with a maximum air flow rate of 2210 m3/hr in conjunction with indoor and outdoor environmental chambers simulating respective environments. The experimental results showed HRV heating sensible effectiveness between 67 % and 63 % and IEC cooling total effectiveness between 81 % and 71 % with increasing air flow rates. A detailed numerical model was developed to predict the performance of the IEC/HRV over a large range of operating conditions. The IEC model simulates heat and mass transfer from water evaporation in the secondary air and potentially from condensation in the primary air during summer season operation. The HRV model simulates heat transfer and potentially mass transfer from secondary air condensation during winter season operation. The detailed physics-based model was compared with experimental data, and it predicted the performance with high accuracy for both summer and winter operating conditions. The average absolute errors for supply air temperature between the experimental results and model predictions were 0.2 °C in HRV winter mode and 1.0 °C in IEC summer mode. The validated IEC model was used to further explore the possibility of combined ventilation and passive space cooling without a supplemental air-conditioner. The analysis shows that utilizing IEC for summer operation offers high cooling COP and even the potential for passive space cooling, which is not possible with conventional energy recovery ventilators (ERV).

How does vehicle emission control policy affect air pollution emissions? Evidence from Hainan Province, China

Vehicular emissions have become important sources of air pollution in China. Regarding the environmental impacts of vehicle emission control policies (VECPs), changes in air pollutants and CO2 emissions have attracted more attention. Hainan is the first province in China declared to ban the sale of fuel-powered cars by 2030, aiming to accelerate cutting down the local air pollution emissions. However, there is no previous study examining how these VECPs would affect air pollutants in Hainan. Further, research on whether the controls would lead to a real carbon reduction is limited. Therefore, this paper quantitatively assesses the emission changes of primary air pollutants (including NOx, CO, VOCs, PM2.5, PM10, and PMTSP) and greenhouse gases (CO2, CH4, and N2O) in the transportation sector with regard to different VECPs in Hainan. The results reveal that (1) VECPs would lead to significant increases in vehicular population by 21 %–65 % in 2025–2050. Specifically, light-duty cars and buses with 4-stroke engines (LD4Cs) is the largest contributor and banning sales of fuel-powered vehicles would lead to a larger increase of 1914.6 thousand (64 %) in 2030; (2) for air pollutant emissions, the policy scenario would bring notable reduction effects, decreasing by 1.0 %–16.0 % and 16.7 %–38.7 % in 2030 and 2050 (PM excluding), respectively, suggesting VECPs play important roles in alleviating environmental pollution; (3) conversely, for CO2 emissions, the policy scenario would cause increases of 0.8 Mt. (17.8 %) and 0.3 Mt. (6.1 %) in 2035 and 2050, respectively, indicating promoting new energy vehicles (NEVs) would increase carbon emissions. Meanwhile, it suggests that CO2 emission in the transportation sector of Hainan peaked in 2020. This research highlights that VECPs would be a double-edged sword, leading to air pollutants reductions but not necessarily decline CO2 emissions. This fact would further accelerate mechanism and technological innovation in transport to alleviate air pollution and carbon emissions simultaneously.

Study on Combustion Characteristics and NOx Formation in 600 MW Coal-Fired Boiler Based on Numerical Simulation

The variations in the boiler operation conditions have a great effect on the combustion characteristics and the pollutant formation in furnaces. This work aims to investigate the effects of operational parameters on NOx formation and its distribution in furnaces using the numerical simulation method to obtain the optimum control strategy for reducing NOx emissions. The numerical simulation models of pulverized coal combustion in furnaces involving flow, heat transfer, combustion and NOx formation are established. Taking a 600 MW supercritical opposed firing pulverized coal boiler as the study object, a full-scale three-dimensional physical model of the boiler is constructed with Gambit software. On this basis, the pulverized coal combustion and the NOx formation under various boiler loads are numerically simulated using the software of Ansys Fluent 2021R1, and the accuracy and the reliability of the models established are verified by comparing the simulation data with the field test data. According to the combustion numerical simulation of 128 groups of operating conditions, the effects of boiler load, the air rate and the air temperature on combustion and NOx formation have been emphatically investigated. The simulation results indicate that the formation of NOx and the NOx concentration distribution are mainly affected by the oxygen concentration and the temperature in the furnace. Especially, the effects of the variation in the excess air coefficient, the over-fire air (OFA) ratio, the primary air ratio and the internal secondary air ratio on NOx concentration distribution vary greatly. When the air temperature increases the overall NOx concentration in the furnace increases, and the influence of the secondary air temperature and the OFA temperature is greater than that of the primary air temperature. Large amounts of simulation data are a necessary data source for further study on the NOx prediction model at the economizer outlet, which can improve the prediction ability and the generalization ability of the NOx prediction model.

Synthesis of a SiO2/Co(OH)2 Nanocomposite Catalyst for SOX/NOX Oxidation in Flue Gas

Sulfur and nitrogen oxides (SOX/NOX) are the primary air toxic gas pollutants emitted during fuel combustion, causing health and environmental concerns. Therefore, their emission in flue gases is strictly regulated. The existing technologies used to decrease SOX/NOX content are flue gas desulfurization, which necessitates high capital and operating costs, and selective catalytic reduction, which, in addition to these costs, requires expensive catalysts and high operating temperatures (350–400 °C). New wet scrubbing processes use O3 or H2O2 oxidants to produce (NH4)2SO4 and NH4NO3 fertilizers upon ammonia injection. However, these oxidants are expensive, corrosive, and hazardous. SiO2/Co(OH)2 nanocomposites are presented here as potential catalysts for SOX/NOX oxidation in wet scrubber reactors to scrub these toxic gases using atmospheric oxygen as the oxidant at relatively low temperatures of 60–90 °C. Several silica-cobalt-oxide-based nanocomposites were synthesized as potential catalysts at different concentrations and temperatures. The nanocomposite catalysts were characterized and exhibited excellent catalytic properties for SOX/NOX oxidation using atmospheric oxygen as the oxidant, replacing the problematic H2O2/O3. We thus propose SiO2-supported Co(OH)2 nanoparticles (NPs) as excellent catalysts for the simultaneous scrubbing of polluting SOX/NOX gases in flue gases using atmospheric O2 as the oxidation reagent at a relatively low-temperature range.

Monitoring Air Pollution in Greek Urban Areas During the Lockdowns, as a Response Measure of SARS-CoV-2 (COVID-19).

The online version contains supplementary material available at 10.1007/s11270-022-06024-7.

Differential cardiopulmonary effects of isoprene-versus toluene-generated photochemically-Aged smog in rats

Photochemical smog is a complex mixture of primary and secondary air pollutants including secondary organic aerosols (SOA), ozone and reactive aldehydes which has been linked to increased risk of adverse cardiovascular and pulmonary responses. The components and related health effects of smog are thought to be determined both by the precursor chemicals and reaction conditions. Here we examined the difference between isoprene- (IS-) and toluene- (TL) generated smog in causing cardiopulmonary effects in rats. Wistar-Kyoto rats were exposed to either filtered air (FA) or smog for 4 h. IS-smog contained 660 ppb NO2, 335 ppb O3, and 178 μg/m3 SOA while TL-smog had 380 ppb NO2, 250 ppb O3, and 1,250 μg/m3 SOA. Whole-body plethysmography was performed at baseline and after each exposure and left ventricular function was measured using a Millar probe and arrhythmic sensitivity to aconitine. Tidal volume decreased only after IS-smog while inspiratory time and nasal injury increased following both smog atmospheres. Only TL-smog caused an increase in PenH, which is an indicator of airway irritation. On the other hand, only IS-smog caused left ventricular pressure to decrease, while only TL-smog increased sensitivity to cardiac arrhythmia. These data indicate that the source of smog atmosphere plays a large role in the types of responses it elicits and that its relative SOA and gaseous composition determine the extent of cardiovascular versus respiratory effects.