Indoor Atmosphere Research Articles

The determination of equilibrium factor of radon and thoron using LR-115 type II detector in a selected area from Basra Governorate, Iraq

The inhalations of radon 222Rn progeny are the most important source of irradiation of the human respiratory. Studies of underground miners of uranium and other minerals have provided reasonably firm estimates of the risk of lung cancer associated with exposure to radon progeny. It is well established that the absorbed radon dose in the lung is mainly due to radon progeny, but not the radon gas itself. Therefore, long-term measurements of the concentrations of radon progeny or the equilibrium factor F, together with a measurement or an estimation of the aerosol size distribution, are needed to accurately assess the health hazards contribution from radon progeny. Radon, thoron and their progeny are present in the indoor atmosphere as free and bound fractions. The ventilation level in the house played an important effect on the equilibrium between them. This paper presents the results of the measurement of the equilibrium factor F between radon, thoron and their progenies in dwellings and estimates an experimental relationship for the F-factor based on track density instead of typical value of UNISCEAR (about 0.4), which varies significantly with time and place. In this paper, we described a method of theoretical calculation of F and experimentally determined the F-factor using LR-115 type-2 plastic track detectors in closed and bare mod. The exposures were made with a cup and bare dosimeters distributed in 34 houses distributed in different locations of Basra Governorate. The measured F-factor between radon and progeny varied from 0.01 to 0.98 with an average value of 0.38 while the same factor for thoron and progeny was found to vary from 0.0004 to 0.3794 with an average value of 0.0877. These values were in a good agreement with the global F-factor estimated by ICRP. In present investigation about the F-factor, theoretical calculations using graphical solutions supported by experimental technique have been carried out. It is found that the globally assumed F-factor from UNSCEAR and our experimentally obtained value are in good agreement. For a more accurate estimation of the effective dose, one should measure the F-factor at each site considering all the effective parameters like the ventilation factors. The equilibrium factor was found to be small in some houses due to the very intensive ventilation system in the house.

Comparative analysis of heating systems used in Orthodox churches

This work displays a numerical examination of the improvement of indoor atmosphere conditions inside an Orthodox church of Iasi. The objective consists in proposing a solution for reducing the risk of condensation for the case of the real heating system with hot air, used in Three Holy Hierarchs Monastery of Iasi. The solution was to use the local ventilation at towers, that generates air flow in these zones and evacuate humidity. This configuration was tested numerically and the results highlighted its effects. For comparison, the local ventilation was studied for two other heating solutions that are largely used in this type of buildings, underfloor heating and static heaters. The simulations demonstrated that the local ventilation represents a suitable solution when it is combined with the hot air heating.

Chemiresistive Sensing of Ambient CO2 by an Autogenously Hydrated Cu3(hexaiminobenzene)2 Framework.

A growing demand for indoor atmosphere monitoring relies critically on the ability to reliably and quantitatively detect carbon dioxide. Widespread adoption of CO2 sensors requires vastly improved materials and approaches because selective sensing of CO2 under ambient conditions, where relative humidity (RH) and other atmosphere contaminants provide a complex scenario, is particularly challenging. This report describes an ambient CO2 chemiresistor platform based on nanoporous, electrically conducting two-dimensional metal–organic frameworks (2D MOFs). The CO2 chemiresistive sensitivity of 2D MOFs is attained through the incorporation of imino-semiquinonate moieties, i.e., well-defined N-heteroatom functionalization. The best performance is obtained with Cu3(hexaiminobenzene)2, Cu3HIB2, which shows selective and robust ambient CO2 sensing properties at practically relevant levels (400–2500 ppm). The observed ambient CO2 sensitivity is nearly RH-independent in the range 10–80% RH. Cu3HIB2 shows higher sensitivity over a broader RH range than any other known chemiresistor. Characterization of the CO2-MOF interaction through a combination of in situ optical spectroscopy and density functional theory calculations evidence autogenously generated hydrated adsorption sites and a charge trapping mechanism as responsible for the intriguing CO2 sensing properties of Cu3HIB2.

Anomalously high unattached fraction of 220Rn decay products in the atmosphere of monazite storage facility

High levels of the unattached 212Pb fraction of the 220Rn decay products in the atmosphere of the monazite storage facility were found: f1 = 0.3–0.5 at the aerosol concentration of 20 000 cm−3 and 0.1–0.16 at aerosol concentration ∼140 000 cm−3. It is shown that the sampling of aerosols in an atmosphere with a high concentration of thoron result in the local change of the equilibrium between the attached and unattached fractions near the sampling point. As a result, the measured value of the unattached fraction of thoron decay products may differ by several orders of magnitude from the mean value of unattached fraction the in the indoor atmosphere. A local increase of the unattached fraction 212Pb can take place in the worker's breathing zone in the atmosphere with a high concentration of thoron and it should be taken into account in the assessment of the inhalation intake of the thoron decay products for workers.

Oxygen Vacancies Promoted the Selective Photocatalytic Removal of NO with Blue TiO2 via Simultaneous Molecular Oxygen Activation and Photogenerated Hole Annihilation.

Semiconductor photocatalytic technology has great potential for the removal of dilute gaseous NO in indoor and outdoor atmospheres but suffers from unsatisfactory NO-removal selectivity due to undesirable NO2 byproduct generation. In this study, we demonstrate that the 99% selectivity of photocatalytic NO oxidation toward nitrate can be achieved over blue TiO2 bearing oxygen vacancies (OVs) under visible-light irradiation. First-principles density functional theory calculation and experimental results suggested that the OVs of blue TiO2 with localized electrons could facilitate the molecular oxygen activation through single-electron pathways to generate ·O2- and simultaneously promote the photogenerated hole annihilation. The generated ·O2- directly converted NO to nitrate, while the hole annihilation inhibited the side-reaction between holes and NO to avoid toxic NO2 byproduct formation, resulting in the highly selective removal of NO. This study reveals the dual functions of OVs in defective photocatalysts and also provides fundamental guidance for the selective purification of NO with photocatalytic technology.

Exploring the Potential of Simulation Model Calibration an Acoustical Retrofit Case Study

The success of gastronomic facilities is due, not in a small part, to perceived indoor atmosphere. This includes not just the interior design but also lighting and acoustics. Especially acoustics is a crucial parameter concerning the perception of the environment, but it is often neglected. The present case study investigates the usability and accuracy of acoustics simulation as applied to the retrofit project of a restaurant. The restaurant space was modelled in CAD-based modelling environment. Subsequently, acoustical simulations based on ray tracing were conducted and the simulation model was calibrated based on on-site measurements of the reverberation time. The initial simulation showed large deviations from the measured values, mainly because of uncertainties in the input data concerning the absorption properties of the used materials. Within three calibration steps, the model was revised, such that better results could be achieved. Subsequently both the initial and the calibrated models were used to develop strategies for the improvement of the acoustical performance of the space. After the implementation of the new design options in the restaurant, measurements were repeated. Again the results were compared with both the initial and the calibrated model. The results suggest that the calibrated model displayed a better performance regarding the prediction of post-retrofit circumstances when compared to the non-calibrated one.

Assessing indoor gas phase oxidation capacity through real-time measurements of HONO and NOxin Guangzhou, China

The hydroxyl radical (OH) is one of the most important oxidants controlling the oxidation capacity of the indoor atmosphere. One of the main OH sources indoors is the photolysis of nitrous acid (HONO). In this study, real-time measurements of HONO, nitrogen oxides (NOx) and ozone (O3) in an indoor environment in Guangzhou, China, were performed under two different conditions: (1) in the absence of any human activity and (2) in the presence of cooking. The maximum NOx and HONO levels drastically increased from 15 and 4 ppb in the absence of human activity to 135 and 40 ppb during the cooking event, respectively. The photon flux was determined for the sunlit room, which has a closed south-east oriented window. The photon flux was used to estimate the photolysis rate constants of NO2, J(NO2), and HONO, J(HONO), which span the range between 8 × 10-5 and 1.5 × 10-5 s-1 in the morning from 9:30 to 11:45, and 8.5 × 10-4 and 1.5 × 10-4 s-1 at noon, respectively. The OH concentrations calculated by photostationary state (PSS) approach, observed around noon, are very similar, i.e., 2.4 × 106 and 3.1 × 106 cm-3 in the absence of human activity and during cooking, respectively. These results suggest that under "high NOx" conditions (NOx higher than a few ppb) and with direct sunlight in the room, the NOx and HONO chemistry would be similar, independent of the geographic location of the indoor environment, which facilitates future modeling studies focused on indoor gas phase oxidation capacity.

Influence of electronic cigarette vaping on the composition of indoor organic pollutants, particles, and exhaled breath of bystanders.

The changes of particles and organic pollutants in indoor atmospheres as consequence of vaping with electronic cigarettes have been analyzed. Changes in the composition of volatile organic compounds (VOCs) in exhaled breath of non-smoking volunteers present in the vaping environments have also been studied. The exposure experiments involved non-vaping (n = 5) and vaping (n = 5) volunteers staying 12h together in a room (54m2) without external ventilation. The same experiment was repeated without vaping for comparison. Changes in the distributions of particles in the 8-400nm range were observed, involving losses of nucleation-mode particles (below 20nm) and increases of coagulation processes leading to larger size particles. In quantitative terms, vaping involved doubling the indoor concentrations of particles smaller than 10μm, 5μm, and 1μm observed during no vaping. The increase of particle mass concentrations was probably produced from bulk ingredients of the e-liquid exhaled by the e-cigarette users. Black carbon concentrations in the indoor and outdoor air were similar in the presence and absence of electronic cigarette emissions. Changes in the qualitative composition of PAHs were observed when comparing vaping and non-vaping days. The nicotine concentrations were examined separately in the gas and in the particulate phases showing that most of the differences between both days were recorded in the former. The particulate phase should therefore be included in nicotine monitoring during vaping (and smoking). The concentration increases of nicotine and formaldehyde were small when compared with those described in other studies of indoor atmospheres or health regulatory thresholds. No significant changes were observed when comparing the concentrations of exhaled breath in vaping and no vaping days. Even the exhaled breath nicotine concentrations in both conditions were similar. As expected, toluene, xylenes, benzene, ethylbenzene, and naphthalene did not show increases in the vaping days since combustion was not involved.

Efficiency of the Air-Pollution Control System of a Lead-Acid-Battery Recycling Industry

The air-pollution control system of a lead-acid-battery recycling industry was studied. The system comprised two streams with gravity settlers followed by filter bags for the factory indoor air and the metal-recycling furnace, respectively. Efficiency in particle removal according to mass was found to be 99.91%. Moreover, filter bags and dust from the gravity settlers were analyzed for heavy metals by Wavelength Dispersive X-Ray Fluorescence. The results showed high concentrations of Pb and Na in all cases. In the filter bag samples from the indoor atmosphere stream, Ca, Cu, Fe, and Al were found in concentrations higher than that in the filter bag samples from the furnace stream. The opposite was found for Na. Tl and K were only found in furnace stream bag filters. The elemental concentration of the dust from the furnace fumes stream contained mainly Fe, Na, Cd, Pb, Sb, and Cl, while the indoor main stream contained mainly P, Fe, Na, Pb, and Sb. In all cases, impurities of Nd, Ni, Rb, Sr, Th, Hg, and Bi were found. The high efficiency of the air-pollution control system in particle removal shows that a considerable reduction in emissions was achieved.

Impact of ambient PM2.5 on adverse birth outcome and potential molecular mechanism

PM2.5 (particulate matter ≤2.5 µm in aerodynamic diameter) refers to atmospheric particulate matter (PM) with an aerodynamic diameter of equal and less than 2.5 µm that tends to be suspended for long periods of time and travel over long distances in both outdoor and indoor atmospheres. PM2.5, along with the toxic compounds attached on it, may cause a wide range of disorders. The fetus is considered to be highly susceptible to a variety of toxicants including atmospheric pollutants such as PM2.5 through prenatal exposure. To better understand the relationship between maternal exposure to PM2.5 and adverse birth outcomes for reproduction and fetus development, we studied the published data on this issue including case-control studies, cohort studies and meta-analyses studies, and summarized the basic impact of ambient particulate matter on adverse birth outcomes. Research evidence indicates that PM2.5 has a potential to induce low birth weight (LBW), preterm birth (PTB), and stillbirth. A further in-depth analysis shows that oxidative stress, DNA methylation, mitochondrial DNA (mtDNA) content alteration, and endocrine disruptions may all play an important role in PM2.5 induced adverse effects to pregnant women and fetuses. In addition, PM2.5 exposure can cause male reproductive toxicity, leading to associated adverse pregnancy outcomes.

Evaluation of volatile organic compounds coupled to seasonality effects in indoor air from a commercial office in Madrid (Spain) applying chemometric techniques

Volatile organic compounds (VOCs) concentrations depend on several sources and factors, such as temperature, ventilation, and humidity. Sources can be external atmospheric pollution or indoor release from furniture, coatings or occupants. In this context, this study focused on quantification of VOCs present in a confined atmosphere in a commercial office in downtown Madrid, Spain. The influence of seasonal changes in VOCs concentrations was evaluated using chemometric approaches. Indoor air was systematically monitored for one year using stainless steel tubes filled with Tenax® TA. Sampling was conducted one week a month, for three days during that week (Monday, Wednesday and Friday) for 60 min, every 2 h, totaling 24 h, using an autosampler carousel. The analyses were performed using thermal desorption, and compounds were analyzed by a gas chromatograph coupled with a mass spectrometer. The correlation between these compounds and their concentrations, climatic variations, seasons, among others, were explained by multivariate statistics. Considering the current legislation in Spain, only benzene was present above the maximum permissible concentration (threshold value < 1 μg/m3) from all analyzed compounds. The results indicate that concentrations are related to significant environmental changes, such as ventilation, the number of occupants in the office and types of activity undertaken in the environment. The chemometric analyses allowed the identification of structure analyses correlations between multiple variables for the one-year study. These results underscore the importance of indoor atmosphere studies and chronic exposure to these contaminants.

Influence of advanced wood-fired appliances for residential heating on indoor air quality

This work was aimed at studying particulate matter (PM) in the indoor atmosphere of two flats where airtight biomass systems were used for domestic heating. PM10 and PM2.5 samples were collected by means of nine parallel sampling units, located in the outdoor and indoor areas of each flat. The samples were analyzed for PM macro-components (organic carbon, elemental carbon, macro-elements and inorganic ions) and for the soluble and residual fractions of micro-elements; the influence of the main PM sources on the indoor air quality was evaluated.The results confirm that infiltration from outdoor represents the main source of fine particles, while dust re-suspension, enhanced by the movements of the inhabitants, is one of the most important sources of coarse particles. Biomass-fueled heating systems are a significant source of indoor pollution, mainly due to the cleaning operations required for the removal of residual ash, which release particles in both the fine and the coarse size range. The impact of these operations resulted in indoor to outdoor ratios higher than one for most of the considered PM components. Very high amounts of copper and manganese, elements likely involved in the generation of oxidative stress, were released into the environment during ash removal from the pellet stove. Although this operation was very limited in time (about 15 min), the average concentration of Cu and Mn in PM10 and PM2.5 during the study period (18 days) was more than six times (Cu) and about twice (Mn) the concentration values measured outdoors.

A Comparative Study on the Statutory and Technical Regulations for Controlling Indoor Volatile Organic Compounds in Taiwan and Japan

The objective of this paper was to offer a comparative analysis of currently implemented statutory and technical regulations in Taiwan and Japan for volatile organic compounds (VOC) in indoor atmospheres. The findings should help to manage indoor air quality (IAQ) based on public and occupational health considerations. The first part of the present study summarizes the Indoor Air Quality Management Act in Taiwan and related regulations for building materials. We further highlight that Taiwan became the second country in the world to enact an IAQ management law in 2011. In addition, the permissible exposure limits (PEL) are also addressed to recognize safe levels of VOC concentrations below which adverse health effects are not expected to occur in the workplace environment. In the second part of the paper, the statuses of statutory and voluntary regulations for IAQ issues in Japan are compiled from the official websites of the central ministries, including the Ministry of Education, Culture, Sports, Science and Technology, the Ministry of Land, Infrastructure, Transport and Tourism, and the Ministry of Health, Labor and Welfare. This analysis shows that both countries have adopted similar processes to establish the IAQ standard/guideline values and low-emission building materials, despite slight differences in their methods and central ministries. In contrast, the VOCs regulated by these regulations differ completely, with the exception of formaldehyde. Although the IAQ standards in Taiwan seem to be more stringent than those in Japan, Japan’s longer experience shows a diversity of management tools and regulations based on the guideline values.

A comprehensive air quality investigation at an aquatic centre: Indoor/outdoor comparisons.

Air quality and comfort parameters in a naturally ventilated aquatic centre were studied in relation to the outdoor pollution levels. Simultaneous measurements of PM 2.5, as well as of volatile organic compounds, were carried out for the indoor and outdoor environment of the aquatic centre. The chemical analysis of ionic species and trace elements associated with particulate matter was also performed. In addition, automated analyzer for NO2 and O3 was used in order to record the indoor and outdoor levels of these pollutants. Analysis of diurnal variation of the pollutants' concentration was applied to the collected data, allowing the identification of potential variation on the sources affecting the indoor air quality. PM 2.5 concentration was almost two times higher indoors than outdoors with average values of 13.96 and 6.78μg/m3, respectively. Concerning the ion fraction of PM 2.5, SO42- and Ca2+ were the ions with higher concentration indoors with values of 1.06 and 0.93μg/m3, respectively, while the percentage of Cl- to the PM 2.5 fraction of the indoor atmosphere (9%) was too high than outdoor ones (1%). These results showed that indoor air of swimming pool concerning PM 2.5 and ionic species is mainly affected by the chlorination process along with the comfort conditions (high relative humidity) created during the operation of the facility. The common volatile organic compound concentrations at indoor air are generally in higher levels, compared to the outdoor air with p,m-xylene and toluene to be the substances with the higher concentration for indoor and outdoor area, respectively (7.80 and 1.57μg/m3); nevertheless, values were rather low compared with the findings of other studies. Also, they clearly demonstrate a diurnal variation as a result of poor ventilation during night. As it was expected, chloroform showed the highest concentration compared to the other volatile organic compounds with values ranging from 3.35 to 135.89μg/m3, with an average of 54.50μg/m3. Concerning the NO2 concentration, indoor levels showed an increased pattern when the swimming pool was fully occupied, a fact that reveals a possible correlation. As an overall conclusion, the natural ventilation and the disinfection process seem to play a key role to the air quality of the indoor air of the aquatic centre.

Multiyear indoor radon variability in a family house - a case study in serbia

The indoor radon behavior has complex dynamics due to the influence of the large number of different parameters: the state of indoor atmosphere (temperature, pressure, and relative humidity), aerosol concentration, the exchange rate between indoor and outdoor air, construction materials, and living habits. As a result, indoor radon concentration shows variation, with the usual periodicity of one day and one year. It is well-known that seasonal variation of the radon concentration exists. It is particularly interesting to investigate indoor radon variation at the same measuring location and time period, each year, due to estimation of individual annual dose from radon exposure. The long-term indoor radon measurements, in a typical family house in Serbia, were performed. Measurements were taken during 2014, 2015, and 2016, in February and July, each year. The following measuring techniques were used: active and charcoal canisters methods. Analysis of the obtained results, using multivariate analysis methods, is presented.

Self-Powered Electrostatic Filter with Enhanced Photocatalytic Degradation of Formaldehyde Based on Built-in Triboelectric Nanogenerators

Recently, atmospheric pollution caused by particulate matter or volatile organic compounds (VOCs) has become a serious issue to threaten human health. Consequently, it is highly desirable to develop an efficient purifying technique with simple structure and low cost. In this study, by combining a triboelectric nanogenerator (TENG) and a photocatalysis technique, we demonstrated a concept of a self-powered filtering method for removing pollutants from indoor atmosphere. The photocatalyst P25 or Pt/P25 was embedded on the surface of polymer-coated stainless steel wires, and such steel wires were woven into a filtering network. A strong electric field can be induced on this filtering network by TENG, while both electrostatic adsorption effect and TENG-enhanced photocatalytic effect can be achieved. Rhodamine B (RhB) steam was selected as the pollutant for demonstration. The absorbed RhB on the filter network with TENG in 1 min was almost the same amount of absorption achieved in 15 min without using TENG. Meanwhile, the degradation of RhB was increased over 50% under the drive of TENG. Furthermore, such a device was applied for the degradation of formaldehyde, where degradation efficiency was doubled under the drive of TENG. This work extended the application for the TENG in self-powered electrochemistry, design and concept of which can be possibly applied in the field of haze governance, indoor air cleaning, and photocatalytic pollution removal for environmental protection.

Crystal phase-controlled synthesis of BiPO4 and the effect of phase structure on the photocatalytic degradation of gaseous benzene

As a typical wide-band-gap semiconductor, BiPO4 (BPO) has a great potential for photocatalytical degradation of highly stable benzene (C6H6) that has been regarded as a priority hazardous VOC substance in the indoor atmosphere. Hexagonal (H-BPO), monoclinic (M-BPO), and their mixture phase BiPO4 (M/H-BPO) were selectively synthesized to study the effect of BPO phase structure on the degradation of C6H6. The samples were characterized by several techniques, including X-ray diffraction, FTIR spectroscopy, UV–vis diffuse reflection spectroscopy, N2 absorption-desorption measurements, scanning/transmission electron microscopy, and X-ray photoelectron spectroscopy. The results indicated that the monoclinic phase was a thermodynamically stable phase. The band gap energy of H-BPO, M-BPO, and M/H-BPO was 3.74, 3.93 and 3.86eV, respectively. A transformation from rice-like hexagonal BPO to monoclinic phase nanorods was realized through varying the hydrothermal temperature and the composition of the solvent. The degradation of C6H6 was closely associated with the crystalline phase of BPO and the mineralization rates decreased in order of M– (7.3)>M/H– (1.51)>H-BPO (0.51μmol·h−1·m−2). The rates were higher than that of well-known P25 (0.34μmol·h−1·m−2). The highest activity of M-BPO could be ascribed to its intrinsic distortion of PO4 tetrahedron and the largest band gap structure. OH, O2−, and photoinduced holes were the major oxidation species accounting for the destruction of C6H6.

Characterization of chemical contaminants generated by a desktop fused deposition modeling 3-dimensional Printer

ABSTRACTPrinting devices are known to emit chemicals into the indoor atmosphere. Understanding factors that influence release of chemical contaminants from printers is necessary to develop effective exposure assessment and control strategies. In this study, a desktop fused deposition modeling (FDM) 3-dimensional (3-D) printer using acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) filaments and two monochrome laser printers were evaluated in a 0.5 m3 chamber. During printing, chamber air was monitored for vapors using a real-time photoionization detector (results expressed as isobutylene equivalents) to measure total volatile organic compound (TVOC) concentrations, evacuated canisters to identify specific VOCs by off-line gas chromatography-mass spectrometry (GC-MS) analysis, and liquid bubblers to identify carbonyl compounds by GC-MS. Airborne particles were collected on filters for off-line analysis using scanning electron microscopy with an energy dispersive x-ray detector to identify elemental constituents. For 3-D printing, TVOC emission rates were influenced by a printer malfunction, filament type, and to a lesser extent, by filament color; however, rates were not influenced by the number of printer nozzles used or the manufacturer's provided cover. TVOC emission rates were significantly lower for the 3-D printer (49–3552 µg h−1) compared to the laser printers (5782–7735 µg h−1). A total of 14 VOCs were identified during 3-D printing that were not present during laser printing. 3-D printed objects continued to off-gas styrene, indicating potential for continued exposure after the print job is completed. Carbonyl reaction products were likely formed from emissions of the 3-D printer, including 4-oxopentanal. Ultrafine particles generated by the 3-D printer using ABS and a laser printer contained chromium. Consideration of the factors that influenced the release of chemical contaminants (including known and suspected asthmagens such as styrene and 4-oxopentanal) from a FDM 3-D printer should be made when designing exposure assessment and control strategies.

One-step in-syringe dispersive liquid–liquid microextraction and GC-FID determination of trace amounts of di(2-ethylhexyl) phthalate and its metabolite in human urine samples

Di(2-ethylhexyl) phthalate (DEHP) is used as plasticizer in polyvinylchloride (PVC) plastics. Its metabolites and the parent phthalates are considered toxic. As the DEHP plasticizers are not chemically bound to PVC, they can migrate, evaporate or be leached into indoor air and atmosphere, foodstuff, and other materials. We have reported a novel, easy and available analytical method for the determination of DEHP and its metabolite, mono(2-ethylhexyl) phthalate (MEHP) in human urine samples by the in-syringe dispersive liquid–liquid microextraction method coupled with gas chromatography with flame ionization detector. The limits of detection and precision (RSD) were 2.5 μg/L and 1.4% for DEHP and 1.1 μg/L and 3.0% for MEHP, respectively. This method could be utilized for routine monitoring of the trace DEHP and MEHP in urine of human exposure to plasticizers.

Simulation of airflow with heat and mass transfer in an indoor swimming pool by OpenFOAM

Several CFD (computational fluid dynamics) simulations of the three-dimensional airflow with heat and mass transfer in a complex geometry indoor swimming pool were performed using the OpenFOAM software. A solver has been developed to take into account the mass transfer and the appropriate thermal boundary conditions. Several turbulence models RANS (Reynolds-Averaged Navier-Stokes) types were used. The comparison of numerical results with experimental measurements of air velocity, temperature and humidity showed good agreement regardless of the turbulence model. In order to evaluate the weather effect on the indoor atmosphere of the swimming pool, two simulations were carried out with winter and summer weather conditions. Their comparison showed a very small effect on the internal environment which is manifested by a greater temperature stratification in winter. Furthermore, the effect of swimmers on the indoor atmosphere of the swimming pool was evaluated and found to be of great importance. The main advantageous effect is the homogenization of the temperature and the specific humidity in the occupied space. On the other hand, its major adverse effect is the increase of the specific humidity in the air.