Chamber Studies Research Articles

Phosphorus adsorption, availability, and potential loss characteristics in an Ultisol‐derived paddy soil chronosequence, using a stirred‐flow chamber study

AbstractThe adsorption characteristics, availability, and a loss risk of phosphorus (P) in paddy soil chronosequences had not been well established. In the present study, P adsorption characteristics of paddy soil chronosequence with 0, 7, 22, or 80 years of paddy cultivation history (PS0, PS7, PS22, and PS80, respectively) were identified by P adsorption isotherm, envelope, and stirred‐flow chamber (SFC) kinetics, along with the assessment of P availability and loss risks. Results indicated that P adsorption and desorption followed the same order of PS0 > PS7 > PS22 > PS80. Pearson's correlation analysis revealed P adsorption capacity was significantly and positively correlated with the concentrations of both free iron (Fe) and aluminum (Al) (hydro)oxides (Fed and Ald, respectively), suggesting that the major P sorbents were Fed and Ald. Findings from SFC adsorption kinetics suggested that the kinetics of both P adsorption and desorption were biphasic, being fast in the first 100 min (75.11%–87.57% of P adsorbed and 79.00%–88.65% of P released), followed by a slow phase for the remaining 180 min. Bray‐P increased with the duration of rice cultivation and reached a maximum of 77.90 mg kg−1 at PS80, along with the highest P saturation degree and equilibrium phosphorus concentrations of 7.56% and 2.33 mg L−1, respectively. Hence, with an increasing duration of paddy cultivation, there was a less pronounced P sink function and a lower P availability, but a higher P loss risk, indicating that P availability in the younger and loss risk in the older Ultisol‐derived paddy soils deserve greater attention.

Thermal comfort chamber study of Nordic elderly people with local cooling devices in warm conditions

In this study, we investigated the thermal response of Nordic elderly people before and after using local cooling devices in warm conditions. A climate chamber was used to simulate warm environments. We studied three types of local cooling devices: a table fan, an evaporative cooling device, and an air-cooled jacket. A total of 26 elderly participants were recruited for this study. During the experiments, votes of thermal and air movement perception were collected. The elderly voted for a neutral temperature of 26 °C, preferred temperature of 26.5 °C, and an acceptable temperature of 28 °C. Local thermal sensation in the torso areas of the elderly affected their overall thermal sensation more than local thermal sensation in the extremities under warm conditions. When the ambient temperature was risen to 1 °C and 4 °C higher than 26 °C, the behavior pattern of using local cooling devices for the elderly was: 1) with the small rise the use rate reached 50% with the lower speed modes mainly chosen; and 2) the higher rise caused more people to choose higher speed modes. Our findings show that the three local cooling devices can increase thermal acceptability under warm conditions. More than 80% of elderly accepted the 28 °C thermal environment, and less than 80% accepted 32 °C. The acceptance rate for air movement after using devices was decreased and less than 80% in most conditions. Moreover, all devices performed better under low-humidity conditions.

Assessment of the distribution and volume of air chambers around the inner auditory canal on high-resolution computed tomography scans of the temporal bone.

Assessment of the distribution and volume of air chambers around the inner auditory canal on high-resolution computed tomography scans of the temporal bone.

Summary of PM2.5 Measurement Artifacts Associated with the Teledyne T640 PM Mass Analyzer Under Controlled Chamber Experimental Conditions Using Polydisperse Ammonium Sulfate Aerosols and Biomass Smoke

Particulate matter (PM) is a major primary pollutant emitted during wildland fires that has the potential to pose significant health risks to individuals/communities who live and work in areas impacted by smoke events. Limiting exposure is the principle measure available to mitigate health impacts of smoke and therefore the accurate determination of ambient PM concentrations during wildland fire events is critical to protecting public health. However, monitoring air pollutants in smoke impacted environments has proven challenging in that measurement interferences or sampling conditions can result in both positive and negative artifacts. The EPA has performed research on methods for the measurement of PM2.5 in a series of laboratory based studies including evaluation in smoke. This manuscript will summarize the results of the laboratory based evaluation of federal equivalent method (FEM) analyzers for PM2.5 with particular attention being given to the Teledyne-API Model T640 PM Mass analyzer, as compared to the filter-based federal reference method (FRM). The T640 is an optical-based PM analyzer and has been gaining wide use by state and local agencies in monitoring for PM2.5 U.S. National Ambient Air Quality Standards (NAAQS) attainment. At present, the T640 (includes both T640 and T640X) comprises ~40% of the PM2.5 FEM monitors in U.S. regulatory monitoring networks. In addition, the T640 has increasingly been employed for the higher time resolution comparison/evaluation of low-cost PM sensors including during smoke impacted events. Results from controlled non-smoke laboratory studies using generated ammonium sulfate aerosols, demonstrated a generally negative T640 measurement artifact that was significantly related to the PM2.5 concentration and particle size distribution. Results from biomass burning chamber studies demonstrated positive and negative artifacts significantly associated with PM2.5 concentration and optical wavelength dependent absorption properties of the smoke aerosol. Implications The results detailed in this product will provide state and local air monitoring agencies with the tools and knowledge to address PM2.5 measurement challenges in areas frequently impact by wildland fire smoke. The observed large positive and negative artifacts in the T640 PM mass determination has the potential to result in false exceedances of the PM2.5 NAAQS or in the disqualification of monitoring data through an exceptional event designation. In addition, the observed artifacts in smoke impacted air will have a detrimental effect on providing reliable public information when wildfires occur and also in identifying reference measurements for small sensor evaluation studies. Other PM2.5 FEMs such as the BAM-1022 perform better in smoke and are comparable to the filter based FRM. Care must be taken in choosing high time resolution FEM monitors that will be operated at smoke impacted sites. Accurate methods, such as the FRM and BAM-1022 will reduce the burden of developing and reviewing exceptional event request packages, data loss/disqualification, and provide states with tools to adequately evaluate public exposure risks and provide accurate public health messaging during wildfire/smoke events.

Estimating benthic Fe and reactive solute fluxes

The flux of dissolved Fe (Fed) from sediments is a critical component of the biogeochemical Fe cycle. Common approaches to estimating these fluxes are based on modeling of Fed porewater profiles or incubating sediment and overlying water using benthic chambers or retrieved cores. Inadequate resolution of pore water Fe profiles in the uppermost mm of sediments and rapid Fe2+oxidation can greatly compromise these approaches. These limitations may be partially responsible for large variations in reported benthic Fed fluxes at given values of independent controlling variables such as sedimentary Corg remineralization rates. A series of laboratory experiments were conducted to compare methods to estimate Fe fluxes and confirmed that Fed2+ is oxidized to Fe3+ within a few minutes in oxygenated chamber water. The resulting Fe3+ colloids do not pass through 0.2 μm pore size filters and are also rapidly lost from suspension. Loss from suspension is partially reversible. Most benthic chamber studies do not correct for such losses and likely significantly underestimate Fed fluxes. Additional reactive components such as P and trace metals that associate with precipitated Fe-oxides must be subject to similar major losses during flux measurements. We modified the standard incubation methods by circulating overlying water through Fe extractors and accumulating Fed released into chambers over a known period at constant O2 and pH. We found using a range of experimental conditions that in cylindrical chambers ∼70–93% of introduced Fe2+ is typically recovered on accumulators at saturated O2 (∼270 μM) and seawater pH (∼8; NBS). We recommend that flux incubations that target reactive solutes (e.g., Fe, P) be configured with flow-through extractors, and pre-calibrated for losses specific to chamber designs, chamber water residence times, and deployment conditions (e.g., O2, pH).

Quantifying the Root-to-Shoot Transfer of 4,4'-Methylenedianiline Using Pressure Chamber and Intact Plant Methods.

The high-production-volume chemical 4,4'-methylenedianiline (4,4'-MDA) is an aromatic amine used to manufacture 4,4'-methylenedianiline diisocyanate for polyurethane production. Based on 4,4'-MDA's octanol/water partition coefficient (KOW ) and correlations with the transpiration stream concentration factor (TSCF), significant plant uptake and root-to-shoot transfer are predicted. However, most correlations between KOW and TSCF were developed for neutral organics and may not be applicable for ionizable bases such as 4,4'-MDA. To investigate, TSCF values for 4,4'-MDA were measured using pressure chamber and intact plant approaches for tomato, soybean, and wheat (intact plants only). 14 C-labeled 4,4'-MDA was used to increase analytical sensitivity and facilitate measurement of distribution within plant tissues. The TSCF of 14 C-MDA determined using the pressure chamber method was 0.04 ± 0.00 for tomato and 0.17 ± 0.10 for soybean. These values were lower than predicted from log KOW and within the range of values for 14 C-pyrene also measured in our study (0.14 ± 0.00 for tomato and 0.16 ± 0.09 for soybean). The TSCF values calculated from measurements made from intact plants grown to maturity were statistically equivalent to those obtained from the pressure chamber method for soybean and tomato. The distributions of 14 C within the three plants species were similar, with the roots > leaves ≈ stems > fruit. The log root concentration factors for 4,4'-MDA ranged from 3.68 to 4.33 for the three plant species. This finding indicates that the aromatic amine sorption to root materials is much greater than would be predicted based on its log KOW and may be the reason for the limited root-to-shoot transfer observed in the pressure chamber and intact plant studies. Environ Toxicol Chem 2023;42:655-662. © 2023 SETAC.

Involvement of CYP3A4 and MDR1 in altered metabolism and transport of indinavir in 1,25(OH)2D3-treated Caco-2 cells

Altered drug concentrations may induce unexpected toxicity or treatment failure; thus, understanding the factors that alter the pharmacokinetic profiles of drugs is crucial for optimal disease treatment. Vitamin D receptor (VDR), a nuclear receptor, regulates the expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance protein 1 (MDR1), which are crucial determinants of drug pharmacokinetics. In this study, we investigated the effects of 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3], a VDR ligand, on the metabolism, transport, and pharmacokinetics of indinavir, a dual substrate of CYP3A4 and MDR1. 1,25(OH)2D3 treatment for three days upregulated the expression levels of CYP3A4 and MDR1 in Caco-2 cells and consequently led to an increase in the level of a metabolite formed via CYP3A4 (indinavir M6) and the efflux ratio of indinavir in transport study. The increase in the metabolic reaction was also confirmed through a metabolism assay performed using the lysate of 1,25(OH)2D3-treated Caco-2 cells. In the Ussing chamber study conducted with the rat intestine, 1,25(OH)2D3 treatment did not alter the transport of indinavir into the basolateral side but increased indinavir M6 formation. Similarly, plasma levels of the metabolite increased in 1,25(OH)2D3-treated rats; however, systemic exposure to indinavir led to insignificant alterations. Considering the overlapping substrate specificities for CYP3A4 and MDR1 and their significant roles in drug pharmacokinetics, VDR may play an important role in drug interactions of CYP3A4 and MDR1 substrates for accessing more effective and safe disease treatments.

Effects of cleaning spray use on eyes, airways, and ergonomic load

BackgroundCleaning workers are exposed to chemicals and high physical workload, commonly resulting in airway problems and pain. In this study the response in the upper airways and the physical workload following airborne and ergonomic exposure of cleaning spray was investigated.MethodsA survey was answered by professional cleaning workers to investigate their use of cleaning sprays and the perceived effects on eyes, airways and musculoskeletal pain. A human chamber exposure study was then conducted with 11 professional cleaning workers and 8 non-professional cleaning workers to investigate the airborne exposure, acute effects on eyes and airways, and physical load during cleaning with sprays, foam application and microfiber cloths premoistened with water. All cleaning products used were bleach, chlorine, and ammonia free. The medical assessment included eye and airway parameters, inflammatory markers in blood and nasal lavage, as well as technical recordings of the physical workload.ResultsA high frequency of spray use (77%) was found among the 225 professional cleaning workers that answered the survey. Based on the survey, there was an eight times higher risk (p < 0.001) of self-experienced symptoms (including symptoms in the nose, eyes and throat, coughing or difficulty breathing) when they used sprays compared to when they cleaned with other methods. During the chamber study, when switching from spray to foam, the airborne particle and volatile organic compound (VOC) concentrations showed a decrease by 7 and 2.5 times, respectively. For the whole group, the peak nasal inspiratory flow decreased (-10.9 L/min, p = 0.01) during spray use compared to using only water-premoistened microfiber cloths. These effects were lower during foam use (-4.7 L/min, p = 0.19). The technical recordings showed a high physical workload regardless of cleaning with spray or with water.ConclusionSwitching from a spraying to a foaming nozzle decreases the exposure of both airborne particles and VOCs, and thereby reduces eye and airway effects, and does not increase the ergonomic load. If the use of cleaning products tested in this study, i.e. bleach, chlorine, and ammonia free, cannot be avoided, foam application is preferable to spray application to improve the occupational environment.

Impact of simulated flight conditions on supraventricular and ventricular ectopy

Though billions of passengers and crew travel by air each year and are exposed to altitude equivalents of 7000–8000 feet, the health impact of cabin oxygenation levels has not been well studied. The hypoxic environment may produce ectopic heartbeats that may increase the risk of acute in-flight cardiac events. We enrolled forty older and at-risk participants under a block-randomized crossover design in a hypobaric chamber study to examine associations between flight oxygenation and both ventricular (VE) and supraventricular ectopy (SVE). We monitored participant VE and SVE every 5 min under both flight and control conditions to investigate the presence and rate of VE and SVE. While the presence of VE did not differ according to condition, the presence of SVE was higher during flight conditions (e.g. OR ratio = 1.77, 95% CI: 1.21, 2.59 for SVE couplets). Rates of VE and SVE were higher during flight conditions (e.g. RR ratio = 1.25, 95% CI: 1.03, 1.52 for VE couplets, RR ratio = 1.76, 95% CI: 1.39, 2.22 for SVE couplets). The observed higher presence and rate of ectopy tended to increase with duration of the flight condition. Further study of susceptible passengers and crew may elucidate the specific associations between intermittent or sustained ectopic heartbeats and hypoxic pathways.

Будівельні композитні матеріали на основі деревини: оцінка безпеки в Україні та система технічного регулювання в ЄС

Abstract. Composite building materials based on wood (further ‒ wood plastics) remain a key object of sanitary and hygienic research as an important source of marker air pollutants in residential premises. Aim. Generalization of the results of sanitary and hygienic studies of wood plastics that are in circulation on the market of Ukraine; comparative analysis of individual provisions of the system of technical regulation of the specified products in the EU and Ukraine. Materials and Methods. Directives of EU countries in the field of technical regulation of chemically hazardous construction materials and sanitary legislation of Ukraine; data of sanitary-hygienic researches of the air of residential premises based on complaints of residents of the city of Kyiv, carried out by the "Kyiv City Center for Disease Control and Prevention of the Ministry of Health of Ukraine" (2010-2019); the results of chamber studies of samples (N=4859) of building products based on wood plastics and furniture, performed in the polymer hygiene laboratory of the State Enterprise "L.I. Medved’s Research Center of Preventive Toxicology, Food and Chemical Safety of the Ministry of Health of Ukraine" (2010-2019). Statistical analysis ‒ Microsoft Excel 2019. Results. According to the research data of wood-plastic samples, a high level of their compliance with technical requirements and quality parameters and hygienic standards of Ukraine was established, so over the 10 years of research, the average deviations were: glued plywood, veneered panels, other laminated wood materials - 3.59% (n=1234); fiberboard boards made of wood or other wood materials with or without the addition of resins or other substances ‒ 1.36% (n=1512); chipboard boards, with oriented chips and similar boards (for example, wafer boards) ‒ 1.73% (n=1441); furniture samp-les – 1.6% (n=672). At the same time, an increase in the number of cases of exceeding the concentration of phenol and formaldehyde in relation to the MPC average daily in the air of residential premises of multi-apartment buildings during the same period was found: phenol by 2.86 times (R2=0.764), formaldehyde by 2.7 times (R2=0.529). The difference between wood-plastic samples sent for sanitary-hygienic research and those products that enter residential premises is not excluded, and cases of wood-plastic use in residential premises that are not intended are also found. Fundamental differences in the approaches of the EU and Ukraine to the assessment of the safety of composite building materials still remain unsettled. Difficulties in adapting the product safety regulatory system in the EU for introduction in Ukraine are due to the methodology of risk assessment for human health as a key tool for substantiating product and commodity safety standards. The main distinguishing feature of the EU legal framework on this issue is the recognition of product safety based on the absence of unacceptable risk, and the methodology that was implemented in the Soviet period (more than 30-40 years ago) is based on the principle of "zero risk". Conclusions. There is a need to harmonize the EU system of technical regulation and safety for construction products based on wood with the approaches that are in force in Ukraine, which will contribute to updating the national sanitary legislation, methodology, criteria, and methodical approaches to ensure the safety of a wide range of construction products for the population. An effective tool on this path can be the development and implementation of a targeted interdisciplinary state program. Key Words: wood plastics, risk assessment, technical regulation.

New particle formation and growth during summer in an urban environment: a dual chamber study

Abstract. Nucleation and subsequent growth are a major source of new particles in many environments, but the pollutants involved and the details of the corresponding processes are still under debate. While sulfuric acid has a major role in new particle formation under a lot of conditions, the role of ammonia, amines, and organic vapors is less clear. In most continental areas, new particle formation is quite frequent especially on relatively clean, sunny days when there is some sulfur dioxide available. In parts of the Eastern Mediterranean even if all the previous requirements are satisfied, new particle formation events are relatively rare during summertime. In this work, we take advantage of this unexpected low, new particle formation frequency in Greece and use a dual atmospheric simulation chamber system with starting point ambient air in an effort to gain insight about the chemical species that is limiting nucleation in this area. A potential nucleation precursor, ammonia, was added in one of the chambers, while the other one was used as a reference. Three different types of outcomes were observed: new particle formation only in the perturbed chamber, new particle formation in both chambers, and no observed new particle formation. The addition of ammonia assisted in new particle formation in almost 50 % of the experiments conducted. The growth rate of the newly formed particles ranged from 3–11 nm h−1, with particles reaching a diameter of 20–25 nm after a few hours. The nucleation rate was estimated using an aerosol dynamics model and was found to be in the range of 500 to 25 000 particles cm−3 h−1 in the different experiments. These results support the hypothesis that ammonia at levels of several ppb can accelerate or even cause new particle formation, at least in the environment of the Eastern Mediterranean.

The effectiveness of potted plants in improving indoor air quality: A comparison between chamber and field studies

People spend up to 90% of their time inside buildings, making indoor air quality an extremely important factor affecting public health and building design. Due to the inherent ability to absorb/filter pollutants, plants present a promising method for improving indoor air quality. In recent decades, many studies have quantified plants’ effectiveness in removing indoor air pollutants using both chamber and field methods. This paper presents a review working covering these studies and discusses the differences between chamber and field studies, in terms of study methods and results. Through a meta-analysis of 41 chamber studies and 16 field studies, the effectiveness of 182 species in removing 25 pollutants has been estimated. From this work, a larger proportion of significant results were observed in chamber studies (88%), comparing to field studies (65%). Additionally, comparable studies revealed greater removal effectiveness of plants in chamber studies. These discrepancies could be attributed to many factors, such as the size and the airtightness of experimental setup, ventilation, gas exposure scheme, and environmental conditions. It is envisaged that these findings will help reduce the gap between chamber studies and field studies, and provide guidance for the future use of plants in buildings to improve indoor air quality.

Effect of OH scavengers on the chemical composition of α-pinene secondary organic aerosol.

OH scavengers are extensively used in studies of secondary organic aerosol (SOA) because they create an idealized environment where only a single oxidation pathway is occurring. Here, we present a detailed molecular characterization of SOA produced from α-pinene + O3 with a variety of OH scavengers using the extractive electrospray time-of-flight mass spectrometer in our atmospheric simulation chamber, which is complemented by characterizing the gas phase composition in flow reactor experiments. Under our experimental conditions, radical chemistry largely controls the composition of SOA. Besides playing their desired role in suppressing the reaction of α-pinene with OH, OH scavengers alter the reaction pathways of radicals produced from α-pinene + O3. This involves changing the HO2 : RO2 ratio, the identity of the RO2 radicals present, and the RO2 major sinks. As a result, the use of the OH scavengers has significant effects on the composition of SOA, including inclusions of scavenger molecules in SOA, the promotion of fragmentation reactions, and depletion of dimers formed via α-pinene RO2-RO2 reactions. To date fragmentation reactions and inclusion of OH scavenger products into secondary organic aerosol have not been reported in atmospheric simulation chamber studies. Therefore, care should be considered if and when to use an OH scavenger during experiments.

Environmental chamber studies of eye and respiratory irritation from use of a peracetic acid-based hospital surface disinfectant.

To characterize personal exposures and measures of eye and respiratory tract irritation in controlled environmental chamber studies of 44 healthy adult volunteers simulating upper-bound use of peracetic acid (PAA)-based surface disinfectant for terminal cleaning of hospital patient rooms. Experimental, within-subject, double-blinded cross-over design. Objective and subjective exposure effects were assessed for PAA and its components: acetic acid (AA) and hydrogen peroxide (HP). Deionized water was included as a control. Breathing-zone concentrations of PAA, AA, and HP were assessed for 8 female multiday volunteers (5 consecutive days) and 36 single-day volunteers (32 females and 4 males). Wetted cloths were used to wipe high-touch surfaces for 20 minutes per trial. Also, 15 objective measures of tissue injury or inflammation and 4 subjective odor or irritation scores were assessed. Disinfectant trials showed 95th percentile breathing zone concentrations of 101 ppb PAA, 500 ppb AA, and 667 ppb HP. None of the volunteers observed over 75 test days exhibited significant increases in IgE or objective measures of eye and respiratory tract inflammation. Subjective ratings for disinfectant and AA-only trials showed similar increases for odor intensity and nose irritation, with lower ratings for eye and throat irritation. Females were 2.5-fold more likely than males to assign moderate + irritation ratings. Simulated upper-bound hospital use of PAA-based disinfectant led to no significant increases in objective markers of tissue injury, inflammation, or allergic sensitization, and no frank signs of eye or respiratory tract irritation.

ПИЛОТИРУЕМЫЙ КОСМИЧЕСКИЙ ПОЛЕТ И ИССЛЕДОВАНИЯ В ОБЛАСТИ ПРОТЕОМИКИ

Review summarizes the data acquired at the IBMP laboratory of proteomics over the past decade in space and ground model experiments. The use of mass-spectrometry for panorama, semi-quantitative and quantitative analysis of human bio-liquids shed light on the molecular mechanisms, including and nets of molecular interactions involved in the adaptive response of healthy human organism to the extreme conditions in orbital missions, wintering in the Antarctic, and simulation studies such as bed rest (BR), dry immersion (DI), isolation chamber studies, exposure in a hypomagnetic stand and rotation on a short-arm centrifuge. Proteomic investigations revealed the common elements of pathogenesis in the process of adaptation to extreme conditions. The type of blood proteome modification in cosmonauts depended on mission multiplicity. Frequency of protein oxidative modifications induced by spaceflight factors was increased. The actual type of cardiovascular adaptation depended on dominance of either sympathetic or parasympathetic components of the vegetative nervous system. Body response was characterized by changes in blood proteome, loss of orthostatic stability after BR, appearance of undesirable vascular complications following DI, endothelial dysfunction. In future, omix-technologies will be appropriate for risks stratification and development of countermeasures to ensure safety in very long exploration missions to Earth-like planets in the Solar system.

Metal compositions of particle emissions from material extrusion 3D printing: Emission sources and indoor exposure modeling

Material extrusion 3D printing has been widely used in industrial, educational and residential environments, while its exposure health impacts have not been well understood. High levels of ultrafine particles are found being emitted from 3D printing and could pose a hazard when inhaled. However, metals that potentially transfer from filament additives to emitted particles could also add to the exposure hazard, which have not been well characterized for their emissions. This study analyzed metal (and metalloid) compositions of raw filaments and in the emitted particles during printing; studied filaments included pure polymer filaments with metal additives and composite filaments with and without metal powder. Our chamber study found that crustal metals tended to have higher partitioning factors from filaments to emitted particles; silicon was the most abundant element in emitted particles and had the highest yield per filament mass. However, bronze and stainless-steel powder added in composite filaments were less likely to transfer from filament to particle. For some cases, boron, arsenic, manganese, and lead were only detected in particles, which indicated external sources, such as the printers themselves. Heavy metals with health concerns were also detected in emitted particles, while their estimated exposure concentrations in indoor air were below air quality standards and occupational regulations. However, total particle exposure concentrations estimated for indoor environments could exceed ambient air fine particulate standards.

Multi-domain indoor environmental quality in buildings: A review of their interaction and combined effects on occupant satisfaction

Occupant satisfaction is influenced by the interaction and combined effects of multi-domain indoor environmental quality (IEQ) in buildings. While there are literature reviews on multi-domain IEQ, two limitations exist: 1) the reviewed IEQ interactions are mainly limited to two IEQ domains and climate chamber studies; and 2) those reviews have not quantitatively discussed the impact of IEQ interactions on overall satisfaction and only cover limited building types. To address this gap, this study adopts a broad, top-down approach with a three-stage screening to select relevant publications about the four most concerned IEQ domains—thermal comfort, acoustic comfort, visual comfort, and indoor air quality. A total of 74 publications have been selected and reviewed. Our study shows that: 1) existing findings on IEQ interaction and combined effects are inconsistent and somewhat contradictory; 2) interactions among three IEQ domains exist but are much less examined compared to two IEQ interactions. Studies on four IEQ are not found; 3) the current occupant satisfaction models are mainly generalized models. Personal models are an emerging area of research and practice; and 4) the one-vote veto effect exists, i.e., some IEQ domains show a predominating influence on overall satisfaction. We advocate future research 1) to collaborate on a global IEQ database to enable model comparison and the development of standards and guidelines spanning multiple IEQ domains, 2) to investigate personal overall satisfaction models encompassing IEQ interactions; and 3) to further examine non-linear modeling approaches for interpreting the relationships between IEQ and overall satisfaction.

Mitigation of indoor parthenium weed pollen exposure by protective window screens evaluated in chamber study

Pollen from Parthenium weed is a well-known aeroallergen. Infestation of Parthenium weed is found in many countries including Taiwan, especially in central and southern regions. Most houses in Taiwan are equipped with window screens to keep flies and mosquitoes away. Natural ventilation would allow pollens to infiltrate indoors. Hence, preventing pollen infiltration would be a strategy for allergic disease control.A full-scale exposure chamber comprising a main (outdoor) cabin and an auxiliary (indoor) cabin connected by six types of window screen was used in the test. In both cabins, two Burkard samplers continuously collected pollens emitted from Parthenium hysterophorus weed. The filtration efficacy of different window screens under three wind velocities were assessed by counting the number of pollens in both cabins using an optical microscope. Light transmittance was evaluated by picturing the parthenium plant behind the different screen materials. Natural ventilation performance in the two cabins was evaluated using a vane anemometer.Protective window screen D made of long-lasting electrostatic fiber with high pollen filtration efficacy, adequate ventilation, and clear visibility is recommended for naturally ventilated residential buildings, especially for allergic individuals.

Smog chamber study of secondary organic aerosol formation from gas- and particle-phase naphthalene ozonolysis

Naphthalene (Nap), one of the most abundant PAHs in the atmosphere, has been shown to be an important secondary organic aerosol (SOA) precursor. In this study, the gas- and particle-phases (Suspended Nap-coated polystyrene latex spheres (PSLs) generated by vaporization condensation) Nap ozonolysis were investigated in a 1000 L volume cubic Teflon smog chamber. Gas-phase products and Nap-SOAs were observed from the gas- and particle-phase Nap ozonolysis via homogeneous and heterogeneous reactions, respectively. The time-dependent size distribution and mass concentration of Nap-SOAs were analyzed using a scanning mobility particle sizer and a laboratory-developed single-particle aerosol mass spectrometry (SPAMS) instrument. The chemical components of the homogeneous and heterogeneous reaction products were analyzed on-line by single photo ionization mass spectrometry (SPIMS), SPAMS, as well as by thermal desorption gas chromatograph-mass spectrometry. The results showed that the chemical components of the gas-and particle-phase Nap ozonolysis were essentially the same, with the dominant products being phthalaldehyde, phthalic anhydride, 2-carboxybenzaldehyde, and benzoic acid; Nap-SOA formation was attributed to the formation of new particles as well as the uptake of homogeneous and heterogeneous Nap oxidation products on the gas-phase or/and the particle surface. Based on the online measurement results, the reaction mechanism of Nap-ozonolysis also exhibits an initial carbon atom or double-bond attacks by O3, and kinetic analysis of Nap-coated PSLs ozonolysis shows a heterogeneous reaction rate constant of 2.55E-4 s−1 with R2 = 0.984. This study provides a systematic approach to characterize the chemical and physical properties of the gas- and particle-phase Nap ozonolysis in real time, which will deepen our understanding of the migration and transformation of PAHs in the atmosphere.

Feast or famine: How is global change affecting forage supply for Yellowstone's ungulate herds?

The ecological integrity of US national parks and other protected areas are under threat in the Anthropocene. For Yellowstone National Park (YNP), the impacts that global change has already had on the park's capacity to sustain its large migratory herds of wild ungulates is incompletely understood. Here we examine how two understudied components of global change, the historical increase in atmospheric CO2 and the spread of nonnative, invasive plant species, may have altered the capacity of YNP to provide forage for ungulates over the last 200-plus years. We performed two experiments: (1) a growth chamber study that determined the growth rates of important invasive and native YNP grasses that are forages for ungulates under preindustrial (280ppm) versus modern (410ppm) CO2 levels and (2) a field study that compared the effect of defoliation (clipping) on the shoot growth of invasive and native mesic grassland plants under ambient CO2 conditions in 2019. The growth chamber experiment revealed that modern CO2 increased the growth rates of both invasive and native grasses, and invasive grasses grew faster regardless of CO2 conditions. The field results showed a continuum of positive to negative responses of shoot growth to defoliation, with a subgroup of invasive species responding most positively. Altogether the results indicated that the historical increase in CO2 and the spread of invasive species, some of which were planted to provide forage for ungulates in the early and mid-1900s, have likely increased the capacity of forage production in YNP. However, rising CO2 has also resulted in regional warming and increased aridity in YNP, which will likely reduce grassland productivity. The challenge for global change biologists and park managers is to determine how competing components of global change have already affected and will increasingly affect forage dynamics and the sustainability of Yellowstone's iconic ungulate herds in the Anthropocene.