Ambient Particulate Air Research Articles

Ambient air particles: The use of ion chromatography and multivariate techniques in the analysis of water-soluble substances

Seventeen water-soluble substances (of sodium, ammonium, potassium, magnesium, calcium, formate, methanesulfonate, glyoxylate, chloride, nitrite, nitrate, glutarate, succinate, malate, malonate, sulfate and oxalate) in 94 samples of particle matter in the ambient air, collected over ten months, in a suburb of Belgrade (Serbia), were determined by ion chromatography. To apportion the sources of the air pollution, the log-transformed data were processed by applying multivariate techniques. Principal component and factor analysis identified three main factors controlling the data variability: stationary combustion processes with the highest loadings of oxalate, malonate and malate; landfill emission and secondary inorganic aerosol characterized by high levels of ammonium, nitrate and sulfate; a contribution of mineral dust composed of magnesium, calcium and chloride. The hierarchical cluster analysis pointed out a differentiation of the samples into five groups belonging to different variables inputs. For the classification of ambient air samples using nine selected ions, the recognition ability of linear discriminant analysis, k-nearest neighbors, and soft independent modeling of class analogy were 87.0, 94.6, and 97.8 %, respectively. Time-series analysis showed that the traffic emission is more pronounced in winter in contrast to the mineral dust influence, while the effect of waste combustion exhibits no trend.

Microparticles in the air of industrial cities as a risk factor of bronchial asthma

Introduction. Suspended particles in ambient air of cities increase the risk of developing respiratory and cardiovascular diseases. At the same time, data on the role of suspended particles in the formation and complication of the course of bronchial asthma (BA) are extremely limited. The aim of study was to substantiate the design of a study to study the effect of fine suspended particles in atmospheric air on the development of the T2 endotype of BA. The design of a "case-control" study was developed and implemented, including patients with the T2-endotype of BA and persons in the control group. In order to verify the diagnosis of BA, General clinical methods of examination and specific allergological examination are used. In parallel, the quantitative characteristics and qualitative composition of suspended particles in atmospheric air are studied with the determination of the mass of suspended particles, dispersion, chemical and microbiological (muldi-tof mass spectrometry, PCR analysis) composition. Atmospheric air samples will be collected using a cascade impactor in the area where patients with bronchial asthma and control groups live. For each fraction, the following will be analyzed: suspended particle mass, dispersion, chemical and microbiological (muldi-tof mass spectrometry, PCR analysis) composition. Conclusions. The study will assess the risk of T2-endotype formation of bronchial asthma with various quantitative and qualitative characteristics of suspended microparticles in the atmospheric air.

A study of atmospheric pollutants (particulates, metallic elements) at an agricultural site

In this study, the total suspended particulate (TSP) concentrations and dry deposition of ambient air particulates are measured using a high-volume air sampler and a dry deposition plate at an agricultural sampling site in central Taiwan from March of 2019 to February of 2020. In addition, the concentrations of metallic elements attached to the particulates and dry deposits are analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Finally, the TSP and metallic elements concentrations in TSP at different sampling sites around the world are also compared and discussed. The results indicated that the average highest TSP concentrations and dry depositions values both occurred in autumn, and the agricultural sampling site had the average greatest ambient air particulates dry depositions velocities when compared with other previous characteristic-related studies in Taiwan. In addition, metallic element Al had the average highest concentrations and dry depositions and metallic element Cd had the average lowest concentrations and dry depositions values in this study. In addition, metallic elements Cr, Cu, Pb, and Zn had the average highest concentrations when compared with other typical sampling site studies (airport, suburban, downtown, residential, industrial, and wetlands) in central Taiwan. Furthermore, when compared with the other previous metallic elements concentrations found in related studies in other regions from 1978 to 2020, the results obtained in this study indicated that the average metallic element concentrations Cr, Cu, Pb, and Zn in Taiwan were only lower than those reported in India and China. Taiping District is the main fruits production area in central Taiwan. Therefore, continued monitoring of ambient air related pollutants and finding the possible pollution sources have become an important issue for this agricultural site. From the above analysis, we also conclude that ambient air particulates and all the metallic elements dry deposition values obtained in this study were higher than those from the other characteristic sampling sites where studies were previously conducted in Taiwan.

Particulates and metallic elements pollutants concentrations, dry depositions and sources study at a suburban area

In this study, the concentrations and dry deposition of ambient air particulates are measured using a PS-1 sampler and a dry deposition plate at a suburban sampling site in central Taiwan from January 2019 to August 2019. The concentrations of metallic elements that are attached to the particulates and dry deposits are analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The source analysis model was used to identify possible emission sources of the pollutants and the transmission distributions of ambient air metallic elements. During the sampling period, the TSP concentration at the Peiying suburban sampling site was highest on January 24th (in winter) and lowest on April 29th (in spring). Dry deposition was greatest on January 9th (in winter) and least on July 29th (in summer). In addition, the correlation coefficient between temperature and ambient air particulate concentration revealed a moderate to strong negative relationship (r2 = 0.60) the ambient air particulate concentrations declined throughout the study period. Moreover, high concentrations of crustal metallic elements Al, Ca were found in this study due to the particulates suspensions from the roads in the suburban area. The Taiwan II express highway runs about 500 m to the northeast of the sampling site, explaining why high concentrations of Cu were measured in this study. The concentrations of metallic elements Ca, Cd, Ni, Pb, and Zn were highest in winter and spring while those of metallic elements Al, Cu, Cr, and Mn were highest in summer. The mean metallic elemental concentrations followed the order: Ca > Al > Zn > Cu > Mn > Ni > Pb > Cr > Cd. The dry depositions of metallic elements Ca, Pb, Zn, Ni and Cd were greatest in winter and spring and those of metallic elements Al, Cu, Cr and Mn were highest in summer. The average dry depositions of the studied metallic elements followed the order: Ca > Al > Zn > Cu > Mn > Ni > Pb > Cr > Cd. The main pollution parcel was from the north side of Taiwan, pollution parcel that associated with the northeast monsoon, resulted in ambient air pollutants emitted on Taiwan island, influencing its air quality.

How efficiently can HEPA purifiers remove priority fine and ultrafine particles from indoor air?

More than 1 million premature deaths in Asia annually are estimated to be associated with indoor air quality. HEPA (high-efficiency particulate air) filter air purifiers (APs) are widely used in urban Chinese residences by the growing middle class, as public awareness of air pollution increases. Currently, understanding of how particle size affects particle removal is inconsistent, and the rate at which different particle types are removed remains largely unknown. Therefore, this investigation aimed to determine the relationship between particle size and the removal efficiency of particles, and how efficiently ambient air is filtered compared to particle types which are typically used in standard tests (tobacco smoke, dust and pollen). Three of the most popular AP models in China were tested in China’s largest indoor controlled chamber laboratory and the removal efficiencies of particles in the 18–514 nm range were identified. Each AP had a distinct profile of removal efficiency against particle size, but the three APs shared similarities in performance, with removal efficiency consistently lowest at 200–250 nm. This size fraction is important in an exposure context as these particles are abundant in ambient air in mega-cities, can penetrate through building shells effectively, remain airborne for long periods of time and can penetrate the deepest areas of the lungs. Ambient air particles were removed at a similar rate to test particles; this confirms that the Association of Home Appliance Manufacturers’ (AHAM) standards are a suitable proxy for “real world” performance.

Effects of Ultrafine Particles in Ambient Air on Primary Health Care Consultations for Diabetes in Children and Elderly Population in Ljubljana, Slovenia: A 5-Year Time-Trend Study.

Epidemiological studies indicate that exposure to ultrafine particles (UFP) in ambient air represents an important environmental public health issue. The aim of this study was to determine the association between UFP in ambient air and the daily number of consultations in the primary health care unit due to diabetes mellitus in children and elderly population of the Municipality of Ljubljana. A 5-year time-trend ecological study was carried out for the period between 1 January 2013 and 31 December 2017. The daily number of primary health care consultations due to diabetes mellitus among children and elderly population was observed as the health outcome. Daily mean UFP concentrations (different size from 10 to 100 nm) were measured and calculated. Poisson regression analysis was used to investigate the association between the observed outcome and the daily UFP, particulate matter fine fraction (PM2.5), and particulate matter coarse fraction (PM10) concentrations, adjusted to other covariates. The results show that the daily number of consultations due to diabetes mellitus were highly significantly associated with the daily concentrations of UFP (10 to 20 nm; p ≤ 0.001 and 20 to 30 nm; p ≤ 0.001) in all age groups and in the elderly population. In observed the population of children, we did not confirm the association. Findings indicate that specified environmental challenges should be addressed by comprehensive public health strategies leading to the coordinated cross-sectoral measures for the reduction of UFP in ambient air and the mitigation of adverse health effects.

Spatiotemporal Characteristics of Particulate Matters Concentration and Their Influence on Ambient Air Quality in Urban Regions of Khuzestan Province, Iran

Background: One of the most concerning pollutants in urban areas across the globe is particulate matter suspended in the Earth’s atmosphere. The main objective of the current investigation is to explore the spatial and temporal patterns of ambient air particles (PM10 and PM2.5) and PM2.5/PM10 ratio in different urban areas of Khuzestan Province. Methods: In this way, the required data were gathered from the environmental protection organization based on hourly mean concentrations of PM10 and PM2.5 of six air pollution-monitoring sites for 5 years. Results: Results indicated that the average concentrations of PM10, PM2.5, and PM2.5/PM10 are about 134.14±39.23 µg/m3, 44.51±13.44 µg/m3 and 0.33±0.07, respectively. The examinations revealed a reductive trend on annual values of PMs in terms of temporal variations. A detailed investigation of the annual mean concentrations of PMs and PM2.5/PM10 in terms of spatial variations demonstrated the largest values for Naderi-Ahvaz and Abadan stations. Furthermore, the measured AQI was larger than 100 and the Exceedance Factor (EF) values of PM10 and PM2.5 ranged between 1.51-2.73 and 0.77-1.41. The statistical analysis obtained from linear regression revealed a significant positive relation between AQI and PM2.5 and PM10 with correlation coefficients (R2) of 0.8259 and 0.7934, respectively. Conclusion: Although the analysis and measurement revealed a reductive trend in the annual mean concentrations of PM2.5 and PM10, the measured AQI and EF values are still far from the standards of good quality and low pollution. Therefore, it is highly necessary to follow the air pollution protocols to control PM air pollution in Khuzestan Province.

Characterization of trace metals from different particle sizes, sources and contamination identifications for a mixed site in Taiwan

Ambient air particulates (PM1, PM2,5, PM10, PM18, and total suspended particulates (TSP)), trace metals (Al, As, Cr, Cu, Cd, Zn, Ni, Pb, Mn, and Hg(p)) their concentrations, their dry deposition, and their sources from Dec. 2017 to May 2018 at Luliao Taichung City Junior High School (24°14′37.9″N 120°34′00.3″E) were studied. The site is a mixed site that is surrounded by traffic, and urban and commercial activities. The sources of ambient air particulates were identified by back-trajectories analysis. The trace metal concentrations in PM1, PM2.5, and PM10 were compared with those in other countries in the years 2003–2018. The level of contamination by these trace metals at this mixed site was evaluated using a contamination factor (CF) and degree of contamination (CD). The results indicated that the average concentrations of all particles were highest in January (winter season) and the average concentrations of TSP, PM18, PM10, PM2.5, and PM1 followed the order Jan. 2018 > Dec. 2017 > Apr. 2018 > Mar. 2018. The concentration of trace metals followed the order Al > Cu > Fe > Cr > Mn > Ni > As > Pb > Zn > Cd > Hg(p) in both TSP and dry deposits. Al had the highest mean concentration in PM18, PM10, PM2.5, and PM1 while Hg(p) had the lowest concentration in PM18, PM10, PM2.5, and PM1. Interestingly, elements As and Cr had higher mean concentrations in PM1 at the studied site than in the other countries of interest during the years from 2003 to 2018. C F and C D values for all trace metals revealed low degree of contamination at this mixed sampling site. The C D values for all trace metals in particle of sizes 1 to 18 μm all exceeded those calculated for TSP and dry deposits. The C D values increased with particle size from 1 μm to 18 μm.

Assessing atmospheric dry deposition via water-soluble ionic composition of roadside leaves

This study focuses on the water-soluble ion concentrations in the washing solution of leaves of different roadside tree species at three sites in Iran to estimate the ionic composition of the dry deposition of ambient air particulates. All considered water-soluble ion concentrations were significantly higher next to the roads with high traffic density compared to the reference site with low traffic density. The PCA results showed that Ca2+, Mg2+, and originated mainly from traffic activities and geological sources, and Na+, Cl−, K+ and F− from sea salts. In addition to sea salt, K+ and F− were also originated from anthropogenic sources i.e. industrial activities, biomass burning and fluorite mining. Moreover, the concentration of the water-soluble ions depended on species and site. C. lawsoniana had significantly higher ion concentrations in its leaf washing solution compared to L. japonicum and P. brutia which indicates C. lawsoniana is the most suitable species for accumulating of atmospheric dry deposition. From our results, it can be concluded that sites with similar traffic density can have different particle loads and water-soluble ion species, and that concentrations in leaf-washing solutions depend on site conditions and species-specific leaf surface characteristics.

Direct infrared spectroscopy for the size-independent identification and quantification of respirable particles relative mass in mine dusts

Due to the global need for energy and resources, many workers are involved in underground and surface mining operations where they can be exposed to potentially hazardous crystalline dust particles. Besides commonly known alpha quartz, a variety of other materials may be inhaled when a worker is exposed to airborne dust. To date, the challenge of rapid in-field monitoring, identification, differentiation, and quantification of those particles has not been solved satisfactorily, in part because conventional analytical techniques require laboratory environments, complex method handling, and tedious sample preparation procedures and are in part limited by the effects of particle size. Using a set of the three most abundant minerals in limestone mine dust (i.e., calcite, dolomite, and quartz) and real-world dust samples, we demonstrate that Fourier transform infrared (FTIR) spectroscopy in combination with appropriate multivariate data analysis strategies provides a versatile tool for the identification and quantification of the mineral composition in relative complex matrices. An innovative analytical method with the potential of in-field application for quantifying the relative mass of crystalline particles in mine dust has been developed using transmission and diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) within a unified multivariate model. This proof-of-principle study shows how direct on-site quantification of crystalline particles in ambient air may be accomplished based on a direct-on-filter measurement, after mine dust particles are collected directly onto PVC filters by the worker using body-mounted devices. Without any further sample preparation, these loaded filters may be analyzed via transmission infrared (IR) spectroscopy and/or DRIFTS, and the mineral content is immediately quantified via a partial least squares regression (PLSR) algorithm that enables the combining of the spectral data of both methods into a single robust model. Furthermore, it was also demonstrated that the size regime of dust particles may be classified into groups of hazardous and less hazardous size regimes. Thus, this technique may provide additional essential information for controlling air quality in surface and underground mining operations.Graphical

Neurotoxicology of Nanomaterials.

The remarkable advances coming about through nanotechnology promise to revolutionize many aspects of modern life; however, these advances come with a responsibility for due diligence to ensure that they are not accompanied by adverse consequences for human health or the environment. Many novel nanomaterials (having at least one dimension <100 nm) could be highly mobile if released into the environment and are also very reactive, which has raised concerns for potential adverse impacts including, among others, the potential for neurotoxicity. Several lines of evidence led to concerns for neurotoxicity, but perhaps none more than observations that inhaled nanoparticles impinging on the mucosal surface of the nasal epithelium could be internalized into olfactory receptor neurons and transported by axoplasmic transport into the olfactory bulbs without crossing the blood-brain barrier. From the olfactory bulb, there is concern that nanomaterials may be transported deeper into the brain and affect other brain structures. Of course, people will not be exposed to only engineered nanomaterials, but rather such exposures will occur in a complex mixture of environmental materials, some of which are incidentally generated particles of a similar inhalable size range to engineered nanomaterials. To date, most experimental studies of potential neurotoxicity of nanomaterials have not considered the potential exposure sources and pathways that could lead to exposure, and most studies of nanomaterial exposure have not considered potential neurotoxicity. Here, we present a review of potential sources of exposures to nanoparticles, along with a review of the literature on potential neurotoxicity of nanomaterials. We employ the linked concepts of an aggregate exposure pathway (AEP) and an adverse outcome pathway (AOP) to organize and present the material. The AEP includes a sequence of key events progressing from material sources, release to environmental media, external exposure, internal exposure, and distribution to the target site. The AOP begins with toxicant at the target site causing a molecular initiating event and, like the AEP, progress sequentially to actions at the level of the cell, organ, individual, and population. Reports of nanomaterial actions are described at every key event along the AEP and AOP, except for changes in exposed populations that have not yet been observed. At this last stage, however, there is ample evidence of population level effects from exposure to ambient air particles that may act similarly to engineered nanomaterials. The data give an overall impression that current exposure levels may be considerably lower than those reported experimentally to be neurotoxic. This impression, however, is tempered by the absence of long-term exposure studies with realistic routes and levels of exposure to address concerns for chronic accumulation of materials or damage. Further, missing across the board are "key event relationships", which are quantitative expressions linking the key events of either the AEP or the AOP, making it impossible to quantitatively project the likelihood of adverse neurotoxic effects from exposure to nanomaterials or to estimate margins of exposure for such relationships.

Short-term exposure to ambient particle gamma radioactivity is associated with increased risk for all-cause non-accidental and cardiovascular mortality

BackgroundRecent studies have found that particulate matter (PM) attached radioactivity was associated with certain adverse health effects including increased blood pressure and lung dysfunction. However, there has been no investigation on the direct effect of PM radioactivity on mortality. MethodsExposures to ambient PM gamma activities were determined using U.S. EPA RadNet data. Data on daily deaths were obtained from individual state Departments of Public Health. We used a generalized additive quasi-Poisson model to estimate the associations between two-day average ambient PM gamma activities (gamma2 through gamma9) with all-cause non-accidental and cardiovascular daily deaths for each of 18 US cities, for each season, adjusting for two-day average PM2.5 exposure, temperature, relative humidity, day of week and long-term trends. Subsequently, we used random-effects meta-analysis to estimate the overall effect in the 18 cities for each season. ResultsWe found that all-cause non-accidental daily mortality in spring season was positively associated with two-day average ambient PM gamma activities in spring, with significant results for gamma2, gamma5 and gamma6. Similarly, cardiovascular daily mortality was positively associated with two-day average ambient PM gamma activities, with significant results for gamma2, gamma4, gamma5, gamma6, gamma7 and gamma9. For the spring season, each interquartile range (IQR) increase of two-day averaged ambient PM gamma activity was associated with increase in all-cause daily deaths, ranging from 0.15% (95% Confidence Interval (CI): −0.36%, 0.65%) to 1.03 (95%CI: 0.18%, 1.89%). Each IQR was also associated with increase in cardiovascular daily deaths, ranging from 0.01% (95%CI: −0.89, 0.92) to 2.95% (95%CI: 1.33, 4.59). For other seasons overall we found statistically insignificant associations of PM radioactivity with mortality. ConclusionsOur findings suggest that there are potential systemic toxic effects of inhalation of radionuclides attached to ambient air particles.

Ambient air particle mass concentrations in the urban area of the capital city of Yaoundé (Cameroon, Central Africa): monthly and seasonal behaviour

ABSTRACT Two size fractions of particulate matters (PM2.5, PM10-2.5) were sampled for 1 year at an urban site of Yaoundé from March 2018 to February 2019 to describe PM2.5, PM10-2.5 and PM10 pollution variations and determine their main sources. Samples were collected for 24 h on grease-coated filters using a Gent sampler. The analyses were carried out by Gravimetric and statistical methods. The highest monthly average level of the three size fractions were observed in the Long Dry season. Particularly in February (17 ± 13 µg/m3) for PM2.5, in December (51 ± 28 µg/m3) for PM10-2.5 and in January (65 ± 30 µg/m3) for PM10. Whilst the lowest in the Long Rainy season especially in September (5 ± 3 µg/m3) and October (5 ± 4 µg/m3) for PM2.5, in August (6 ± 3 µg/m3) and September (6 ± 3 µg/m3) for PM10-2.5, and in September for PM10 (11 ± 5 µg/m3). Compared to WHO limits, the annual mean was slightly lower for PM2.5 (9 ± 3 µg/m3) and exceedingly higher for PM10 (30 ± 8 µg/m3). However, that pollution level was in line with the lowest WHO Annual Interim Target limits. The correlation between PM2.5 and PM10 varied depending on the seasons. The PM2.5/PM10 ratio was higher in the Long Rainy season and lower in the Long Dry season. The annual ratio was 0.38 ± 0.18 and reflect that coarse particles are more abundant. Thus, the PM pollution in Yaoundé was dominated by dust sources and was close to that of some relatively less polluted developing country capitals around the world. It can also be ranked as the eleventh most airborne polluted African capital.

Assessment and Comparison of Multi-annual Size Profiles of Particulate Matter Monitored at an Urban-industrial Site by an Optical Particle Counter with a Chemometric Approach

Air particulate matter dimensions are a key air quality parameter which can be related to composition, transport properties, exposure and effects on humans and the environment. Optical particle counters are increasingly used for dynamic ambient air particle matter size characterization. Monitoring campaigns lasting several months or years produces millions of single values to be elaborated, requiring effective data treatment procedures for extracting information and knowledge. Data mining algorithms as Self-Organizing Map (SOM) can support exploratory data analysis and pattern recognition in aerosol science. The use of SOM allows to elaborate a high number of data, with powerful visualization features using 2D maps, avoiding to lose information on data variability with data pre-treatments, such as compacting minute data to hourly or daily means. In the present study we describe the optical particle counter data elaboration for particulate matter profile assessment and comparison of a long monitoring time (nearly three years) carried out near residential buildings positioned very close to a steel plant. About twelve millions recorded single values have been handled on the whole. The approach allowed to identify four main particulate matter profiles and follow their variation during the years relating the differences with changes in the plant management and process. The possible applications of the present approach are broad in the field of air quality high frequency long monitoring campaigns with different types of instruments for size and compositional characterization of both particulate matter and gases.

Unraveling the blood transcriptome after real-life exposure of Wistar-rats to PM2.5, PM1 and water-soluble metals in the ambient air

Exposure to particulate matter (PM) is one of the most important environmental issues in Europe with major health impact. Various sizes of PM are suspended in the atmosphere and contributes to ambient air pollution. The current study aimed to explore the differential gene expression in blood, and the effect on the respective biological signaling pathways in Wistar rats, after exposure to PM2.5 and PM1 ambient air particles for an eight-week period. A control group was included with animals breathing non-filtered atmospheric air. In parallel, filtered PM2.5 and PM1 was collected in separate samplers. The results after whole genome microarray analysis showed 23 differentially expressed genes (DEGs) between control and PM2.5 group. In addition, pairwise comparison between control and PM1 group displayed 5635 DEGs linked to 69 biological pathways involved in inflammatory response, cell cycle and carcinogenicity. The smaller the size of the inhaled particles, the more gene alterations are triggered compared to non-filtered air group. More specifically, in inflammation signaling procedures differentially regulated gene expression was shown for interleukin-4 (IL-4), IL-7, IL-1, IL-5, IL-9, IL-6 and IL-2. We have identified that RASGFR1, TRIM65, TRIM33, PLEKHB1, CAR4, S100A8, S100A9, ALPL, NP4 and the PROK2 genes are potential targets for the development of adverse outcome pathways (AOPs) due to “real-life” exposure of Wistar rats. Particle measurements during the exposure period showed elevated concentrations of Fe, Mn and Zn in both PM1 and PM2.5 filter fractions, and of Cu in PM2.5. In addition, water-soluble concentration of metals showed significant differences between PM1 and PM2.5 fractions for V, Zn, As, Pb and Mn. In summary, in this study specific gene biomarkers of exposure to ambient air have been identified and heavy metals that are possibly linked to their altered regulation have been found. The results of this research will pave the way for the development of novel AOPs concerning the health effects of the environmental pollution.

A follow-up study on the characterization and health risk assessment of heavy metals in ambient air particles emitted from a municipal waste incinerator in Zhejiang, China.

To confirm our hypothesis that inhalation might be the primary exposure route of heavy metals for children living in proximity to a municipal waste incinerator (MWI), we conducted a one-year follow up study to characterize the distributions of heavy metals featured in different types of ambient air particles, including PM1, PM2.5 and PM10, at two exposure sites near the MWI (E1 and E2) and one control site (C) in Zhejiang, China. Particle samples were collected by a mid-volume sampler and heavy metals were determined by the inductively coupled plasma mass spectrometry method. The mass concentrations of PM1, PM2.5 and PM10 were 52.0, 85.8 and 100.3μg/m3 at E1 site, while the concentrations were 40.2, 92.1 and 106.6μg/m3 at E2 site and 33.4, 55.6 and 66.1μg/m3 at C site, respectively. Both E1 and E2 had higher PM1, PM2.5 and PM10 levels than C site. The levels of pollution were season dependent, with autumn having the highest levels of PM1, PM2.5 and PM10 across all three sampling sites. Regarding the distributions of heavy metals, Pb accounted for the majority of the seven metals in all groups, ranging from 43.2% to 51.3%, followed by Mn that ranged from 22.0% to 32.0%. The Pb levels of PM1, PM2.5 and PM10 in the MWI area were 22.6, 34.2 and 36.2ng/m3, respectively, while Mn levels were 10.1, 20.0 and 23.5ng/m3, respectively. The health risk assessment results suggested that residents were suffering high non-carcinogenic risk posed by MWI-emitted particle-bound toxic metals, as well as the high lifetime carcinogenic risk. This study revealed that ambient air, no matter whether near or far away from an MWI, bore more PM1, PM2.5 and PM10 particles than general, non-polluted ambient air, especially in autumn.

Measurement of the leak rate of masks used for anticancer drug handling using a mask fitting tester.

Exposure to inhalation of anticancer drugs is frequent in anticancer drug handling. Using an activated carbon mask with the ability to remove particulates and vapors of anticancer drugs may be effective. Mask fitting performance is important, because low fitting performance leads to inhalation via bypassing the mask filter (leak). This study evaluated the leak rate of multiple-shaped masks. Activated carbon and nonactivated carbon masks of the pleated-type (like surgical mask) and cup-type were used. Four pharmacists wore the masks and a fitting tester was employed. The particle reduction rate of particles in ambient air was calculated using: particle count (outside - inside)/outside × 100 (%). Leak rate was calculated as the difference in the particle reduction rate due to the presence or the absence of a seal in the mask surroundings. Reduction rates of the pleated-type nonactivated carbon mask and the pleated-type activated carbon mask were 14.8% and 34.8% (mean). These values significantly increased to 85.6% and 83.3% upon sealing the mask surroundings. Particle reduction rates of the cup-type nonactivated carbon mask and activated carbon mask were 99.3% and 33.6%. When mask surroundings were sealed, these values were 99.6% and 39.2%. Leak rates of pleated-type nonactivated carbon mask, pleated-type activated carbon mask, cup-type nonactivated carbon mask, and cup-type activated carbon mask were 70.8%, 48.5%, 0.3%, and 5.6%, respectively. A difference was found in the leak rate between masks used in anticancer drug handling. Based on the low leak rate, the cup-type activated carbon mask was thought to be effective.

Dry depositions study for semi-open/outdoor environments at a concrete processing factory in ChangHua Coastal Park

This study consisted of the collection and comparison of ambient air total suspended particulates (TSP), PM10, PM2.5 concentrations and dry depositions for semi-open/outdoor environments at a concrete processing factory in ChangHua Coastal Park during the year of 2017 (half-year observation). This study aimed to find the appropriate dry deposition models in the prediction of the semi-open/outdoor dry depositions for this factory. The results indicated that the average TSP, PM10, PM2.5 concentrations in the semi-open environment were all higher than those of the outdoor environment at this concrete processing factory, and the average dry depositions at the outdoor environment were all higher than those from the semi-open environment. A possible reason for this is the lack of any ventilation instrument during the processing period at the semi-open environment. In addition, the factory’s storage area opened directly to the outdoor environment. Ambient air particles were easily suspended in the atmosphere by the high frequency of passing trucks. Thus, high ambient air dry depositions particulates were measured at the outdoor environment. 20 and 23 μm particle sizes were selected as the calculated dry depositions velocities to obtain the calculated dry depositions fluxes for both the Baklanov and Wood models in this study. The above results showed that they exhibited better dry depositions prediction results for estimating outdoor and semi-open environments at this industrial concrete processing factory. Moreover, when comparing the above two models of dry depositions prediction performance, the Wood model exhibited better than the Baklanov model. Finally, this study also indicated that the ambient air particles moved from southeast to northwest Taiwan from July to December. In addition, PM2.5 and PM10 particles concentrations gradually increased from summer through autumn and winter season.

Determination of phthalate esters in total suspended particulates in Central Taiwan

Phthalate esters (PAEs) are ubiquitous contaminants from plasticizers of polyvinyl chloride and other polymers. The investigation of the PAEs in the environment, especially ambient air particulates, is very important. In this study, the determination of PAEs in total suspended particulates (TSP) by using gas chromatography/mass spectrometry (GC/MS) was evaluated. The results indicated that the concentrations of TSP at Luliao sampling site ranged from 40.23 to 94.9 μg m−3. In addition, Di(2-ethylhexyl) phthalate was the most abundant PAEs accounting for 89.7–98.9% of TSP. Total PAEs concentrations in central Taiwan ranged from 20.89 to 86.50 ng m−3. Moreover, the GC/MS method enabling simple, rapid, sensitive and reliable results was adopted in this study. The method is recommended for the analysis of PAEs in TSP samples from the ambient air.

Field measurement on the particle concentrations and exposures in five residential buildings in Korea

This study measured five apartments in the Daejeon. There is higher fluctuation for ambient air particle conditions. The average PN (particle number) concentrations was 5.2x108/m3. There are differences between five sites because of fluctuation for ambient air conditions. Particle concentration has different each occupant schedule. I/O ratios were different by occupancy schedules. Indoor particles exceeded 0.7 μm was significant emitted indoor activities. This result comes from two reasons. 1) Penetration by envelopes. 2) Indoor sources by occupants’ activities. PN decay rate (a+k) were 0.49-4.29 h−1 during indoor peak events. Total emitted particles (σ) was 0.0136.15 x 1013 particles per events. The cooking generated PN were wide range because of different event conditions. The ventilation rate is not enough to remove particles.