Air Particulate Concentrations Research Articles

The plausible pathway of air pollutants and the respiratory system among COVID-19 patients: a systematic literature review

Studies evidence links air pollution to increased risk of COVID-19 infection and severity during the pandemic. Nonetheless, those studies are unable to discuss specific pollutants, such as particulate matter, Sox, and NOx. This systematic literature review aimed to summarize the most recent studies on the links between pollutants and their effects on the respiratory system, in this case, mostly on COVID-19 patients. We searched using electronic databases (PubMed, Springer, ScienceDirect, and Sage) in May 2023. The keywords chosen were connected to respiratory diseases and air pollution. All relevant studies published in peer-reviewed journals between 2020 and 2023 and written in English were considered. We excluded letters and non-original articles. Relevant keywords were used to select papers. A total of 11 articles are eligible to be included in the present review study. It was reported that countries with a high prevalence of COVID-19 also have greater concentrations of surface air particles (PM10 and PM2.5) due to vehicle exhaust and industrial pollution. PM-virus aggregates spread easier across the lungs and the top respiratory system, facilitating viral attachment to the lung epithelium. This study found that tiny particles with an aerodynamic dimension fewer than 2.5 μm (PM2.5) or ten μm (PM10) have the most significant potential influence on the respiratory system compared to other pollutants.

Monitoring and Ensuring Worker Health in Controlled Environments Using Economical Particle Sensors.

Nowadays, indoor air quality monitoring has become an issue of great importance, especially in industrial spaces and laboratories where materials are handled that may release particles into the air that are harmful to health. This study focuses on the monitoring of air quality and particle concentration using low-cost sensors (LCSs). To carry out this work, particulate matter (PM) monitoring sensors were used, in controlled conditions, specifically focusing on particle classifications with PM2.5 and PM10 diameters: the Nova SDS011, the Sensirion SEN54, the DFRobot SEN0460, and the Sensirion SPS30, for which an adapted environmental chamber was built, and gaged using the Temtop M2000 2nd as a reference sensor (SRef). The main objective was to preliminarily assess the performance of the sensors, to select the most suitable ones for future research and their possible use in different work environments. The monitoring of PM2.5 and PM10 particles is essential to ensure the health of workers and avoid possible illnesses. This study is based on the comparison of the selected LCS with the SRef and the results of the comparison based on statistics. The results showed variations in the precision and accuracy of the LCS as opposed to the SRef. Additionally, it was found that the Sensirion SEN54 was the most suitable and valuable tool to be used to maintain a safe working environment and would contribute significantly to the protection of the workers' health.

Widespread occurrence of pesticides in low-income housing

BackgroundLow socioeconomic status (SES) residents living in social housing, which is subsidized by government or government-funded agencies, may have higher exposures to pesticides used in indoor residences since pesticides are applied due to structural deficiencies, poor maintenance, etc.ObjectiveTo estimate exposure of residents in low-SES social housing built in the 1970s to legacy and current-use pesticides and to investigate factors related to exposures.MethodsTwenty-eight particle-phase pesticides were measured in the indoor air of 46 units in seven low-income social housing, multi-unit residential buildings (MURBs) in Toronto, Canada using portable air cleaners deployed for 1 week in 2017. Pesticides analyzed were legacy and current use in the classes: organochlorines, organophosphates, pyrethroids, and strobilurins.ResultsAt least one pesticide was detected in 89% of the units with detection frequencies (DF) for individual pesticides of up to 50%, including legacy organochlorines and current-use pesticides. Current-use pyrethroids had the highest DF and concentrations, with the highest particle-phase concentration for pyrethrin I at 32,000 pg/m3. Heptachlor, restricted for use in Canada in 1985, had the highest estimated maximum total air (particle plus gas phase) concentration of 443,000 pg/m3. Heptachlor, lindane, endosulfan I, chlorothalonil, allethrin, and permethrin (except in one study) had higher concentrations than those measured in low-income residences reported elsewhere. In addition to the intentional use of pesticides to control pests and their use in building materials and paints, tobacco smoking was significantly correlated with the concentrations of five pesticides used on tobacco crops. The distribution of pesticides with high DF in individual buildings suggested that pest eradication programs by the building management and/or pesticide use by residents were the major sources of measured pesticides.ImpactLow-income social housing fills a much-needed demand, but the residences are prone to pest infestation and hence pesticide use. We found exposure to at least 1 of 28 particle-phase pesticides in 89% of all 46 units tested, with the highest DF and concentrations for current-use pyrethroids and long-banned organochlorines (e.g., DDT, heptachlor) due to very high persistence indoors. Also measured were several pesticides not registered for use indoors, e.g., strobilurins used to treat building materials and pesticides used on tobacco crops. These results, which are the first Canadian data for most pesticides indoors, show widespread exposure to numerous pesticides.

Study of air deionization factors

The object of research is the dynamics in the concentration of air ions and suspended particles in atmospheric air and in supply-exhaust ventilation systems. An urgent task is to determine the factors and obtain quantitative data on the deionization of the atmospheric air that enters the environment where people live. Quantitative data on changes in the concentration of air ions depending on the time of day, temperature, and relative air humidity have been established. It was shown that even in the absence of significant man-made influence on the concentration of suspended particles, this indicator is at least 7000 cm-3. In the presence of wind, this indicator reaches 30000 cm-3 and higher. Measurement of the spectrum of suspended particles in the range of 0,3–6,0 μm showed that the predominant fraction is particles with sizes of about 3 μm. Studies have been conducted on changes in the concentrations of air ions in supply-exhaust ventilation systems. It was established that in the air duct made of galvanized iron, which has a length of 16 m, the concentration of negative air ions is reduced by 67 %, and positive by 78 %. Laboratory studies of air deionization in air ducts made of different materials were carried out. There is significant air deionization in metal and cardboard ducts while it is absent in wooden ducts. This indicates the electrical nature of deionization. A calculation method for forecasting the aero-ionic mode of premises, taking into account the factors of air deionization, is proposed. For rooms with supply-exhaust ventilation, a calculation apparatus is proposed taking into account the air exchange rate (the number of complete air changes per unit of time). The results make it possible to choose the required performance of artificial air ionization devices for normalizing the aero-ionic regimes in the premises

Numerical study of airflow pattern and bioaerosol dispersion during door motion in a negative pressure isolation ward

Negative pressure isolation wards are typically equipped with buffer rooms to prevent the spread of infectious bioaerosols into clean areas and facilitate timely removal. The opening and closing process of sliding doors is very common in wards. Since the air exchange characteristics of the doorway affect the risk of infection and the efficiency of particle removal within the buffer room, the boundary transformation method and dynamic numerical simulations are used to study the airflow patterns and particle diffusion during door motion. The corresponding cases for different pressure differences, temperature differences, and door motion modes are compared. The results indicate that under different temperature differences, the particles can be dispersed uniformly in a short time (about 23s), and there is no phenomenon of particle aggregation. Compared to the initial pressure difference, adjusting the initial temperature difference has a more pronounced effect on air infiltration and particle concentration trends. The peak particle concentrations within the buffer zone under negative temperature differences are on average 19.9 % higher compared to the positive temperature differences. However, particle concentrations at negative initial temperature differences decay more rapidly. It is found that by reducing the duration of full door opening from 6s to 2s, the time for particles to be completely removed can be reduced by 30.6 %. This study provides useful information for evaluating the risk of infection and developing operational modes of the buffer room.

Air quality monitoring using multi node slave IoT

Jakarta is the city with the second poorest air quality in the world. IQAir data show that Jakarta's air quality is 159. In addition, the concentration of air particles in Jakarta is 14.2 times higher than the annual guidelines of the World Health Organization (WHO). According to the WHO, exposure to air pollution causes around 7 million premature deaths and millions of years of lost health time each year. Air pollution also stunts children's growth, impairs lung function, etc. Therefore, we need a system that can be used to combine air quality to determine how dangerous a place is with air quality. Knowing air quality, certain policies or actions being taken to overcome this danger. This research aims to build and test a prototype air quality monitoring system using multi-node slaves with the Internet of Things. The prototype development process was carried out by adapting the architectural framework of the air quality monitoring system with the Internet of Things. The testing of prototype results is carried out to sound sensor values and functional success. The results of the test show that the system can run well according to the design made. The DSM501A sensor device functions to detect particles of a size larger than one micrometer, which usually include cigarette smoke, house dust, ticks, spores, pollen, and mildew, and works well so that the controller can read the surrounding air conditions well.

Indoor air concentrations of PM2.5 quartz fiber filter-collected ionic PFAS and emissions to outdoor air: findings from the IPA campaign.

Per- and polyfluoroalkyl substances (PFAS) are prevalent in consumer products used indoors. However, few measurements of ionic PFAS exist for indoor air. We analyzed samples collected on PM2.5 quartz fiber filters (QFFs) in 11 North Carolina homes 1-3 times in living rooms (two QFFs in series), and immediately outside each home (single QFF), for 26 ionic PFAS as part of the 9 months Indoor PFAS Assessment (IPA) Campaign. All targeted PFAS, except for PFDS and 8:2 monoPAP, were detected indoors. PFBA, PFHpA, PFHxA, PFOA, PFOS, and 6:2 diPAP were detected in >50% of indoor samples. PFHxA, PFOA, and PFOS had the highest detection frequency (DF = 80%; medians = 0.5-0.7 pg m-3), while median PFBA concentrations (3.6 pg m-3; DF = 67%) were highest indoors. Residential indoor air concentrations (sum of measured PFAS) were, on average, 3.4 times higher than residential outdoor air concentrations, and an order of magnitude higher than regional background concentrations. Indoor-to-outdoor emission rate estimates suggest that emissions from single unit homes could be a meaningful contributor to PFBA, PFOA, and PFOS emissions in populated areas far from major point sources. Backup QFFs were observed to adsorb some targeted PFAS from the gas-phase, making reported values upper-bounds for particle-phase and lower-bounds for total air (gas plus particle) concentrations. We found that higher concentrations of carbonaceous aerosol were associated with a shift in partitioning of short chain PFCAs and long chain PFSAs toward the particle phase.

CFD elucidation of microscopic particles in a low-volumetric classifier towards effects of Stokes number and density ratio

Due to health concerns, a device that separates soot particles based on their size is commonly used to monitor the concentration of soot particles in ambient air. This numerical study aimed to observe particle flow characteristics in low-volumetric separators and assess their performance under recommended operating conditions. The Computational Fluid Dynamics (CFD) technique, specifically the Discrete Particle Model (DPM) approach, was utilized to analyze the behavior of particles and calculate their velocities. The investigation focused on small harmful particles with sizes of 1 µm, 10 µm, and 20 µm. Three volumetric flow rates close to the manufacturer's suggestion, 10 l/min, 15 l/min, and 20 l/min, were examined to evaluate particle separation efficiency in the low-volumetric impact separator. The study revealed that the operating flow rate and the Stokes numbers of the particles significantly impacted the particle behavior, vorticity strength, and the efficiency of particle classification within the separator. The residence time of particles inside the impact chamber was identified as an important factor for assessing separation performance, as it is crucial to monitor and control the key parameters to optimize the separation process. The investigation recommended a flow rate of 15 l/min for efficient impact separation of the particles (PM1, PM10, PM20). The current classifying percentage for particles smaller than PM10 was approximately 70%. Therefore, future work will investigate the effects of the impact chamber's internal configurations to enhance the separator's efficiency, where the modified structure could be explored and recommended.

Calculating Health and Ecological Risks of Pm2.5, and Lead Pollutants Exposure Among Communities Due to Cement Plant Emission, Maros Indonesia 2023

Purpose: This study assessed the possible impacts of PM 2.5, and Lead exposures on populations and ecology as a result of breathing contaminated air and contaminated soil exposure near the Bosowa cement mill in Maros, Indonesia in 2023. Theoretical Framework: Anthropogenic and lithogenic activities can lead to an increase in the amount of heavy metals in ambient air and in soil as well as a decline in the quality of the environment. Methods: The magnitude of PM 2.5, and Lead were measured during the period of April-June 2023. The level of PM 2.5 on ambient air sampling was conducted using direct reading HAZ-Dust EPAM 5000, uses a laser analyzer in order to measure particulate level matter. The result or time-weighted average (TWA) value directly can be read after the measurement at the site. Then meteorological data was collected from Indonesia Agency for Meteorology, Climatology, and Geophysics online database. Then, lead concentrations on surface Soil were taken and analyzed using AAS. Potential ecological and human health risks. Results and Conclusion: Station 9 had the highest level of PM 2.5 concentration (98.23 g/m3), followed by station 11 (97.14 g/m3). In comparison, station 3 had the lowest amount at (31.24 g/m3) and station 5 had the highest level at 32.91 g/m3, respectively. Additionally, station 10 had the greatest amount of Pb air particulate concentration, followed by station 11 with 88.33 g/m3, while station 6 had the highest level of Pb in surface soil, at 196.90 and 166.91 mg/g, respectively. In comparison, station 15 had the lowest amount at (54.76 mg/g), and station 14 had the highest level at (88.87 mg/g), respectively. The findings implied that both PM2.5 and Pb have medium risks to exposed communities. It could be valuable for managing the air quality due to the industry activities and soil remediation in residential areas. Research Implications: Exposure to PM2.5 and Pb air particulates is more hazardous to the environment than it is to human health. PM2.5 and Pb levels in the soil and air had accumulated. More thought should be given, and remedial action should be set to lowering PM2.5 and Lead concentrations and their consequences on the environment in the research region. Originality/value: This study encompasses relevant study that have conducted between 1990 and 2022 and lucidly summarizes the magnitude of PM2.5 and Pb in the air and soil, in addition this research emphasize the risks of environmental and human due to the PM2.5 and Pb Contamination acutely and chronically.

Seasonal Variation in the Thermal Environment and Health-Related Factors in Two Clustered Recreational Bamboo Forests

Forest thermal environments and health-related factors have a significant impact on user experience and physical benefits. Therefore, it is important to study changes in the thermal environment and health-related factors in recreational forests. Clustered bamboo forests have unique structures featuring high canopy density and extensive understory spaces suitable for recreational activities. However, there is no relevant report on the recreational use of these forests. This study investigated seasonal characteristics in the thermal comfort and health-related factors in two clustered bamboo forests in Southwest China. Microenvironmental parameters and health-related factors (negative air oxygen ions (NAI), airborne particulate matter, airborne microorganisms, and biogenic volatile organic compounds (BVOCs)) were measured in four seasons. The microenvironmental parameters were converted into a physiological equivalent temperature (PET) for each period. The results showed that (1) most of the time, the thermal comfort, air particle, NAI, and bacteria concentrations in the two bamboo forests were superior to the controls and met the standard for recreational activities; (2) thermal comfort environments and health-related factors levels varied between two bamboo forests; and (3) the most abundant compounds in the two bamboo forests in each season were leaf alcohol and 2-hexenal. The two clustered bamboo forests provided a comfortable thermal environment and had clean air and bactericidal abilities in all seasons. The forests emitted BVOCs with fresh grass and leaf fragrances, helping to alleviate the sense of depression among visitors. The results confirm that clustered bamboo forests can provide suitable recreational conditions. The results can be used to guide the management of recreational forests and provide support for the development of bamboo forests.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Балқаш қаласының атмосфералық ауасының ауыр металдармен ластануы

Мақалада Балқаш қаласының атмосфералық ауасының химиялық элементтермен ластану жағдайы талқыланған. Қалқыма бөлшектердің мөлшері РМ-10 стационарлық бақылау нәтижелері бойынша сынамалар 99,6% шаң бөлшектерінің шоғырлануы (құрамы бойынша сараланбаған шаң/аэрозоль) кезінде — 0,8 РШК о.т құрады, РШК о.т. нормасы 0,05 мг/м3, Балқаш қаласының атмосфералық ауасында қатты бөлшектердің бір реттік концентрациясының ең жоғары мөлшері 0,2 РШК болды. Қалқыма бөлшектердің концентрациясының мөлшері РМ-2.5. Нормалар бойынша РМ 2.5 орташа тәуліктік деңгейі 0,25 мг/м3 аспауы керек. Мәліметтер бойынша РМ 2.5 орташа тәуліктік деңгейінің асу еселігі 0,7 мг/м3қатты бөлшектердің бір реттік шоғырлануының ең жоғары РМ-2,5-0,2 РШК болды. Жалпы қала бойынша озонның орташа концентрациясы 1,5 РШК о.т. құрады; күкірт диоксиді-5,4 РШК м.бр.ш.; көміртегі оксиді-2,2 РШК м.бр.ш; азот диоксиді — 2,0 РШК м.бр.ш.; күкіртсутегі-20,1 РШК м.бр.ш. рұқсат етілген ең жоғары бір реттік шоғырлану 0,5 мг/м3 кезінде қолайсыз метеорологиялық жағдайлар кезеңінде күкіртті ангидридтің нақты концентрациясы тиісті РШК-дан 23,7 есе асып түскендігі анықталды.

Analysis of laser-generated plume concentration during in vivo laser hair reduction procedures in a tertiary referral laser dermatology unit.

Air particulate concentrations for a typical day of laser hair reduction procedures in a tertiary referral laser dermatology unit were measured, while all standard operating procedures were followed. Concentrations above the World Health Organisation PM2.5 Air Quality Guidance level were detected even following current guidance on room ventilation and local exhaust ventilation. This suggests that further analysis into this hazard is required to assess the use of current engineering and personal protective equipment controls for operators

Possible influence of sudden stratospheric warmings on the atmospheric environment in the Beijing–Tianjin–Hebei region

Abstract. Using European Centre for Medium-Range Weather Forecasts fifth-generation (ERA5) and second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) reanalysis and surface meteorological observation data, this study explores the possible impact of sudden stratospheric warming (SSW) events on air quality in the Beijing–Tianjin–Hebei (BTH) region. Major SSW events are divided into polar vortex displacement SSW and polar vortex split SSW. As the duration of split SSW events is longer and the stratospheric signal pulses propagate further downward than displacement SSWs, subseasonal variability of the atmospheric particulates in the BTH is larger during split SSWs. The air particulate concentration is light before the SSW onset due to the enhanced perturbation in the troposphere associated with strengthened planetary waves. The air particulate concentration around the SSW onset dates begins to rise due to weakening of the tropospheric disturbance as the enhanced planetary waves enter the stratosphere. In the decaying period of the SSW, the air particulate concentration decreases as the stratospheric negative northern annular mode (NAM) signal propagates downward. Specifically, in the pre-SSW period of displacement (split) SSW events, a wavenumber-1-like (wavenumber-2-like) anomaly pattern is strengthened. The East Asian winter monsoon intensifies as the East Asian trough is deepened, especially before the split SSW event onset, leading to a cleaning period. Around the SSW onset period as the tropospheric perturbation diminishes and the East Asian winter monsoon weakens, a surge of air particulate concentration is observed. After the SSW onset, due to the downward propagation of the stratospheric negative NAM signal, cold anomalies form in northeastern East Asia, especially for split SSWs, corresponding to a cleaning period in the BHT region. The local meteorological conditions during the SSWs are also discussed.

Measurements and predictions of ambient air particulates dry depositions at Taichung Shuinan Economic and Trade Park (T.S.E.T.P) during summer and autumn seasons

This study collected ambient air particulate concentrations and dry depositions at Taichung Shuinan Economic and Trade Park (T.S.E.T.P.) sampling site. The global dry depositions model was applied with known particle sizes, pollutant concentrations in ambient air pollutants dry deposition estimates at T.S.E.T.P. site in Central Taiwan. Statistical analysis of the correlated relationships among ambient air particulate concentration, dry depositions, and dry deposition velocities with respect to the meteorological conditions at T.S.E.T.P. site was also conducted. The results indicated that the average dry deposition fluxes were 377.81 µg/m2*min, the average TSP concentrations were 41.53 µg/m3, and the average dry depositions velocity (Vd ) was 15.26 cm/s. In addition, 40 μm was selected as the best ambient air particulate size for the calculated dry deposition velocities to estimate ambient air dry deposition fluxes using the Global model at this T.S.E.T.P. sampling site. Moreover, ambient air particulates concentrations were higher in the fall season than that of the summer season. Sincepollutants parcels were not easily diffused during the fall season because of the low mixed atmospheric layer in this season. Therefore, atmospheric particulates concentrations were higher from the northern side than that of southern side in this study. Furthermore, wind speed V.S. particulate dry depositions and wind V.S. dry depositions velocity displayed a moderate correlated relationship, while particulate dry depositions V.S. particulate dry depositions velocity presented the highest correlated relationship at this T.S.E.T.P. sampling site. However, particulate dry depositions and dry depositions velocity presented significant differences. Finally, particulate dry depositions and dry depositions velocity were not only highly correlation related but also displayed significant differences at the T.S.E.T.P. sampling site.

Assessment of atmospheric air quality in urbanised areas of the Southern Urals

ABSTRACT The paper reports a study of the concentration of fine particles in the atmospheric air with a diameter of < 2.5 microns (PM2.5) and solid particles with a diameter of < 10 microns (PM10) of urbanised territories. An environmental monitoring device (DT-9881 M) determined the concentration of dust particles, and the amount of adsorbed dust on the leaves of woody plants was determined by the flushing method. The research established that the concentration of solid particles in the atmospheric air PM2.5/PM10 depended on the intensity of motor traffic. A decrease in the content of PM2.5/PM10 was revealed in plantings where the influence of forest air on human beings was recorded. Measurements on the content of formaldehyde and carbon monoxide at all measurement points gave negative indicators. Green spaces are important to human well-being.

Concentration versus number of particles in the assessment of air pollution with particulate matters

In this paper, an assessment study was performed regarding air pollution with particulate matters including submicron particles. The evaluation of the contamination level was performed at a textile production unit in Pascani, Romania, which produces polyester knitwear. In the study, automatic determinations of total suspended particulate matters (TSP), PM 10, PM 2.5, and PM 1 (particle with nominal diameter &lt;10 µm, &lt;2.5 µm, and &lt;1 µm), and submicron particulate matters (0.25, 0.35, 0.50 and 0.70) were performed both outdoor, in the ambient air, and indoor (workplace) in the area of the knitting machines. The correlation between the mass concentrations of submicronic particles (µg/m 3) and the numerical concentrations (number of particles/m3) was studied, too, to establish the most appropriate expression of the air pollution level with particulate matter. The results of the performed tests showed a level of ambient air pollution with particulate matters that exceed the limit values in the case of PM 2.5 and PM 10, the total suspended particulates still falling within the limits established by law. Likewise, in the case of workplace air, the level of inhalable particulate matter (particles with nominal diameter &lt;100 µm), the concentration is below the limit values. Regarding the way of expressing the concentration of air particles, in µg/m3 or in no. particles/m3 the tests indicated better representativeness of the pollution level if the concentration in µg m3 is expressed for the dimensional fractions with diameter ≥ 1 µm and in no. particles/m3 for particles with a diameter of ≤1 µm.

Aerosol particle emission increases exponentially above moderate exercise intensity resulting in superemission during maximal exercise

Many airborne pathogens such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are transmitted indoors via aerosol particles. During exercise, pulmonary ventilation can increase over 10-fold, and therefore, exercisers will exhale a greater volume of aerosol-containing air. However, we currently do not know how exercise affects the concentration of aerosol particles in exhaled air and the overall emission of aerosol particles. Consequently, we developed a method to measure in parallel the concentration of aerosol particles in expired air, pulmonary ventilation, and aerosol particle emission at rest and during a graded exercise test to exhaustion. We used this method to test eight women and eight men in a descriptive study. We found that the aerosol particle concentration in expired air increased significantly from 56 ± 53 particles/liter at rest to 633 ± 422 particles/liter at maximal intensity. Aerosol particle emission per subject increased significantly by a factor of 132 from 580 ± 489 particles/min at rest to a super emission of 76,200 ± 48,000 particles/min during maximal exercise. There were no sex differences in aerosol particle emission, but endurance-training subjects emitted significantly more aerosol particles during maximal exercise than untrained subjects. Overall, aerosol particle emission increased moderately up to an exercise intensity of ∼2 W/kg and exponentially thereafter. Together, these data might partly explain superspreader events especially during high-intensity group exercise indoors and suggest that strong infection prevention measures are needed especially during exercise at an intensity that exceeds ∼2 W/kg. Investigations of influencing factors like airway and whole-body hydration status during exercise on aerosol particle generation are needed.

Exposure to chemical substances and particles emitted during additive manufacturing.

Additive manufacturing is an innovative technology that allows the production of three-dimensional objects replicating digital models. The aim of this study was to identify whether the use of this technology in a room without mechanical ventilation system may pose a health risk to its users due to the emission of chemical compounds and fine particles. Measurements were conducted in a furnished space with natural ventilation only, during additive manufacturing on a fused deposition modeling printer with 9 different filaments. Both chemicals and particles were sampled. Volatile organic compounds and phthalic acid esters were determined by gas chromatography-mass spectrometry detection. Carbonyl compounds were determined using the high-performance liquid chromatography with diode-array detection method. Fine particle emission studies were carried out using a DiSCmini particle counter (Testo). In the air samples, numerous chemical substances were identified including both the monomers of the individual materials used for printing such as styrene and other degradation products (formaldehyde, toluene, xylenes). Moreover, 3D printing process released particles with modal diameters ranging from 22.1 to 106.7nm and increased the number concentration of particles in the workplace air. The results of analyses, depending on the type of material applied, showed the presence of particles and chemical substances in the working environment that may pose a risk to human health. Most of the identified substances can be harmful when inhaled and irritating to eyes and skin.

Monitoring ambient air particulates, VOC and CO2 pollutants concentrations, particulates numbers by AQ Guard Ambient sampler

The AQ Guard Ambient sampler is the most advanced compact device that collects ambient air pollutants of various particle sizes. This study collected ambient air pollutant particles of various sizes, CO2 and VOC concentrations and particle numbers from April to May of 2021 using the AQ-guard ambient sampler at Taichung Science Park. The relationships among various particles sizes, CO2, VOC concentrations and total particle numbers in conjunction with the meteorological conditions are also discussed. Appropriate statistical methods were used to test the mean concentration differences between various particulate sizes, CO2, VOC and total particle numbers at Taichung Science Park. The results indicated that particle concentrations of various sizes (PM1, PM2.5, PM4, PM10, PMtot), CO2, VOC concentrations and particulate numbers at the sample location over the study period were the highest on April 21 and gradually decreased from April 21 to May 23, 2021 at Taichung Science Park. The meteorological conditions; temperature, relative humidity and wind speed were negatively displayed but moderately correlated with the ambient air particulate concentrations, CO2, VOC and particulate numbers. The relationships between ambient air particles (PM1, PM2.5, PM4, PM10, PMtot), and CO2, VOC concentrations displayed moderate correlated relationships. The results further showed that there were mean concentration differences existing for most of the pollutants (particulates, CO2 and VOC) monitored by the AQ Guard Ambient sampler in this study. The relationships among particles sizes of PM1 v.s. PM2.5, PM2.5 v.s. PM4, PM4 v.s. PM10, PM10 v.s. PMtot were highly correlated with the mean concentrations. However, the results further showed that they also displayed no significant mean concentration differences for PM1 v.s. PM2.5, PM2.5 v.s. PM4, PM4 v.s. PM10, PM10 v.s. PMtot were collected by the AQ Guard sampler at this Taichung Science Park sampling site.