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Our aim was to assess whether airborne particle counting is an immediate indicator of biocontamination in controlled environment rooms with HEPA filters in a hospital. A prospective study was carried out in a tertiary care hospital between 2016 and 2018. The study was divided in two periods and the measurements were performed in different controlled environment rooms with HEPA filters. The Environmental Biosafety Criterion (EBC) was defined as the absence of fungal and bacterial contamination. In the training period, the area under the ROC curve (aROC) of airborne particle counting and EBC was calculated for each particle size as well as the cut-off points that optimize the combination of sensitivity and specificity in the association between them. aROC is created by plotting sensitivity against 1-specificity. In the testing period, the cut-off points previously selected were validated. 328 measurements were carried out in the training period and 301 in the testing period. In the training period, an association was found between airborne particle counting and EBC. An aROC = 0.760, 95% Confidence Interval (95% CI) 0.695–0.825 was observed for 0.3 µm particles; an aROC = 0.797 (95% CI 0.734–0.860) for 0.5 µm particles; and an aROC = 0.751 (95% CI 0.673–0.829) for 5 µm particles. The cut-off points that optimized the combination of sensitivity and specificity were 9.0 × 103 for 0.3 µm particles, 3.6 × 103 particles for 0.5 µm, and 3.2 × 102 particles for 5 µm. In the testing period, the previous cut-off points were validated. We conclude that airborne particle counting is a useful, immediate, and preliminary measure to identify the presence of biocontamination in controlled environment rooms with HEPA filters.

Regional concentrations and source contributions are calculated for airborne particle number concentration (Nx) and ultrafine particle mass concentration (PM0.1) in the San Francisco Bay Area (SFBA) and the South Coast Air Basin (SoCAB) surrounding Los Angeles with 4 km spatial resolution and daily time resolution for selected months in the years 2012, 2015, and 2016. Performance statistics for daily predictions of N10 concentrations meet the goals typically used for modeling of PM2.5 (mean fractional bias (MFB) ±0.5 and mean fractional error (MFE) 0.1 predicted by regional calculations agree with results from receptor-based studies that use molecular markers for source apportionment at four locations in California. Different sources dominated regional concentrations of N10 and PM0.1 because of the different emitted particle size distributions and different choices for heating fuels. Nucleation (24 %–57 %) made the largest single contribution to N10 concentrations at the 10 regional monitoring locations, followed by natural gas combustion (28 %–45 %), aircraft (2 %–10 %), mobile sources (1 %–5 %), food cooking (1 %–2 %), and wood smoke (0 %–1 %). In contrast, natural gas combustion (22 %–52 %) was the largest source of PM0.1 followed by mobile sources (15 %–42 %), food cooking (4 %–14 %), wood combustion (1 %–12 %), and aircraft (2 %–6 %). The study region encompassed in this project is home to more than 25 million residents, which should provide sufficient power for future epidemiological studies on the health effects of airborne ultrafine particles. All of the PM0.1 and N10 outdoor exposure fields produced in the current study are available free of charge at http://webwolf.engr.ucdavis.edu/data/soa_v3/hourly_avg/ (last access: 20 November 2019).

Exposure to airborne particles causes detrimental health effects, hence their assessment in indoor environments, where people spend most of the time, is important. The influence of energy renovation and occupants' activities on airborne particle concentrations was assessed in seven occupied Swedish residences. Ultrafine particle (UFP

Pulmonary exposure to micro- and nanoscaled particles has been widely linked to adverse health effects and high concentrations of respirable particles are expected to occur within and around many industrial settings. In this study, a field-measurement campaign was performed at an industrial manufacturer, during the production of paints. Spatial and personal measurements were conducted and results were used to estimate the mass flows in the facility and the airborne particle release to the outdoor environment. Airborne particle number concentration (1 &times, 103&ndash, 1.0 &times, 104 cm&minus, 3), respirable mass (0.06&ndash, 0.6 mg m&minus, 3), and PM10 (0.3&ndash, 6.5 mg m&minus, 3) were measured during pouring activities. In overall, emissions from pouring activities were found to be dominated by coarser particles &gt, 300 nm. Even though the raw materials were not identified as nanomaterials by the manufacturers, handling of TiO2 and clays resulted in release of nanometric particles to both workplace air and outdoor environment, which was confirmed by TEM analysis of indoor and stack emission samples. During the measurement period, none of the existing exposure limits in force were exceeded. Particle release to the outdoor environment varied from 6 to 20 g ton&minus, 1 at concentrations between 0.6 and 9.7 mg m&minus, 3 of total suspended dust depending on the powder. The estimated release of TiO2 to outdoors was 0.9 kg per year. Particle release to the environment is not expected to cause any major impact due to atmospheric dilution

Particle size and particle composition are two important variables that potentially affect the performance of low-cost sensors that quantify airborne particle concentrations. In order to investigate how these sensors respond to particles of varying size and composition, we conducted controlled laboratory experiments studying the Plantower PMS5003 sensor and four integrated devices containing Plantower sensors. We challenged the sensors with five particle sources, and for a subset of these sources, we conducted experiments with monodisperse particles ranging between 100 nm and 700 nm. Our results suggest that different sources affect the sensors’ accuracy in their reported particle mass concentration, and this effect on the sensors’ performances appears to be driven by particle size more than composition. During our size-selected experiments, the sensors could detect particles as small as 100 nm, but the both the slopes and R2 values for linear regressions between the sensors and our reference instruments remained below roughly 0.5 until the particle diameter increased to 300 nm. Finally, we demonstrate the sensors cannot apportion the total particle mass concentration into different size fractions on a consistent and accurate basis, which corroborates prior work.

Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown?no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen?virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations. © 2021 National Academy of Sciences. All rights reserved., 1.1.1.2/VIAA/2/18/283; European Cooperation in Science and Technology, COST: CA18226; Academy of Finland, AKA: 318194, PS4A; Ministerio de Educación, Cultura y Deporte, MECD: FPU15/01668; Department of the Environment, Australian Government; Lietuvos Mokslo Taryba; Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, MPNTR: 451-03-68/2020-14/200358; European Social Fund, ESF: 09.3.3-LMT-K-712-01-0066; Helmholtz Association; Christine Kühne – Center for Allergy Research and Education, CK-CARE, ACKNOWLEDGMENTS. We thank Mr. Luis-Leopold Moelter and Mr. Mehmet Gökkaya for assistance in overall data curation. The study was partly implemented in the frame of the European Cooperation in Science and Technology (EU-COST) program, "New approaches in detection of pathogens and aeroallergens (ADOPT)," Grant CA18226 (EU Framework Program Horizon 2020). D.B. and C.T.-H. were supported by the Helmholtz Climate Initiative (HI-CAM), Mitigation and Adaptation. A.Ch. and D.V. were supported by the Municipality of Thessaloniki, Greece (Directorate for the Management of the Urban Environment, Department of Environment). This research has been partly supported by the European Social Fund (Project 09.3.3-LMT-K-712-01-0066) under grant agreement with the Research Council of Lithuania (LMTLT). The study was also partly conducted within the frame of the project of the European Community European Regional Development Fund (EC ERDF) and PostDoc Latvia (Grant 1.1.1.2/VIAA/2/18/283). M.S. acknowledges the Academy of Finland (Project PS4A, Grant 318194). We thank the Department of Health and Rehabilitation of Vinnytsia Regional Council, Ukraine, for providing the numbers of COVID-19 cases. A.H.A. acknowledges Angel Chaves and the Government of Navarra: Institute of Public and Labor Health of Navarra, within LIFE-IP NAdatpa-CC (LIFE16 IPC/ES/000001). A.P. was supported by a predoctoral grant financed by the Ministry of Education, Culture and Sports of Spain, in the Program for the Promotion of Talent and its Employability (Grant FPU15/01668). B.S. acknowledges the Ministry of Education, Science, and Technological Development of the Republic of Serbia (Grant 451-03-68/2020-14/200358). C.T.H. acknowledges the Christine Kühne–Center for Allergy Research and Education (CK-CARE), and The Initiative and Networking Fund of the Helmholtz Association (Immunology & Inflammation). We thank Jan Bumberger, Marcus Karsten, Paul Remmler, Jan C. Simon, and Regina Treudler for data provision and curation from Leipzig, Germany. We thank Claudia Langford Brown and Dana Flanders for statistical advice and scientific discussions. We thank Penelope Jones, Edith Bucher, Reyhan Gumusburun, Haydar Soydaner Karakus, Su Ozgur, and Asli Tetik Vardarli for data curation.

BACKGROUND: The clinical benefits of cardiopulmonary rehabilitation are extensive, including improvements in health-related quality of life, emotional condition, physical function, and overall mortality. The COVID-19 pandemic continues to have a negative impact on center-based cardiopulmonary rehabilitation. Justifiable concern exists that the exercise-related increase in pulmonary ventilation within the rehabilitation classes may lead to the generation of infectious respiratory particles. RESEARCH QUESTION: Is cardiopulmonary rehabilitation while wearing a procedural mask a particle-generating procedure? STUDY DESIGN AND METHODS: Data were collected prospectively at a cardiopulmonary rehabilitation facility with all patients wearing a procedural mask. Small (0.3-4.9 µm) and large (5-10 µm) particle generation was quantified using a light-scattering particle counter. Data were analyzed by time, exertion level, and number of participants. RESULTS: A total of 24 distinct patients attended two or more of the cardiopulmonary rehabilitation classes tested. Most of the patients were men (n = 16 [67%]) and were in rehabilitation because of cardiac disease. During the cardiopulmonary rehabilitation class, small and large micrometer-size particles increased with increasing class size. In classes with four patients or more, a significant increase was found from ambient levels in both small (four patients, P < .01; and five patients, P < .01) and large (four patients, P < .01; and five patients, P < .01) particle count that peaked at about 35 to 40 min during each class. INTERPRETATION: Using an airborne particle counter, we found significant exercise-related increases in both small and large micrometer-size particle generation during cardiopulmonary rehabilitation classes, with larger class sizes (ie, more patients), despite participants wearing a procedural mask.

Summary The COVID‐19 pandemic has led to the production of novel devices intended to protect airway managers during the aerosol‐generating procedure of tracheal intubation. Using an in‐situ simulation model, we evaluated laryngoscopist exposure of airborne particles sized 0.3 ‐ 5.0 microns using five aerosol containment devices (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no aerosol containment device. Nebulised saline was used as the aerosol‐generating model for 300 seconds, at which point, the devices were removed to assess particle spread. Primary outcome was the quantity and size of airborne particles measured at the level of the laryngoscopist’s head at 30, 60, 120, and 300 seconds, as well as 360 seconds (60 seconds after device removal). Airborne particles sizes of 0.3, 0.5, 1.0, 2.5 and 5.0 microns were quantified using an electronic airborne particle counter. Compared with no device use, the sealed intubation box with suction resulted in a decrease in 0.3, 0.5, 1.0 and 2.5 micron, but not 5.0 micron, particle exposure over all time‐periods (p = 0.003 for all time periods). Compared with no device use, the aerosol box showed an increase in 1.0, 2.5 and 5.0 micron airborne particle exposure at 300 seconds (p = 0.002, 0.008, 0.002, respectively). Compared with no device use, neither horizontal nor vertical drapes showed any difference in any particle size exposure at any time. Finally, when the patient coughed, use of the aerosol box resulted in a marked increase in airborne particle exposure compared with other devices or no device use. In conclusion, novel devices intended to protect the laryngoscopist require objective testing to ensure they are fit for purpose and do not result in increased airborne particle exposure.

Commercial spray products are commonly used in daily life and airborne particles generated by these products may cause adverse health effects. Our study was aimed to characterize the behaviors of airborne particles from spray products and to determine the deposition loss rate. Four categories of spray products with highly frequent use - air fresheners, fabric deodorants, window cleaners, and a bathroom cleaner - were selected for the study. The products were applied in a cleanroom according to the instructions for use. Airborne particles (10–10,000 nm) were measured within the breathing zone of a user with a scanning mobility particle sizer and an optical particle spectrometer. Additionally, filter sampling was performed to examine the morphological characteristics of the particles using a field emission-scanning electron microscope (FE-SEM). The initial concentration and particle size distribution varied among different spray types and products. Two propellant-type air fresheners that we tested showed a high initial concentration of smaller sized particles. However, one of these and all hand-pressure type propellants showed a low initial concentration in all size ranges. We observed that particles in nucleation mode (10–31.6 nm) decreased and aggregated particles shifted to accumulation mode (100–1,000 nm) over time. The FS-SEM analysis confirmed the aggregation of nano-sized particles for all products. The deposition loss rates of various particle sizes depended on the initial concentration and distribution of particle sizes. For two air fresheners with high initial concentrations, the loss rate of small-sized particles was higher than that of the other products whereas the particle loss rate of large-sized particles was higher, regardless of initial concentration. The results of this study can give us useful information in the behaviors of airborne particles in the consumer spray products and resulting exposure assessment especially in the application to the exposure modeling of spray products.

Size-fractionated heavy metal concentrations were observed in airborne particulate matter (PM) samples collected from 2014 to 2015 (spanning all four seasons) from suburban (Xianlin) and industrial (Pukou) areas in Nanjing, a megacity of southeast China. Rapid prediction models of size-fractionated metals were established based on multiple linear regression (MLR), back propagation artificial neural network (BP-ANN) and support vector machine (SVM) by using meteorological factors and PM concentrations as input parameters. About 38% and 77% of PM2.5 concentrations in Xianlin and Pukou, respectively, were beyond the Chinese National Ambient Air Quality Standard limit of 75 μg/m3. Nearly all elements had higher concentrations in industrial areas, and in winter among the four seasons. Anthropogenic elements such as Pb, Zn, Cd and Cu showed larger percentages in the fine fraction (o≤2.5 μm), whereas the crustal elements including Al, Ba, Fe, Ni, Sr and Ti showed larger percentages in the coarse fraction (o > 2.5 μm). SVM showed a higher training correlation coefficient (R), and lower mean absolute error (MAE) as well as lower root mean square error (RMSE), than MLR and BP-ANN for most metals. All the three methods showed better prediction results for Ni, Al, V, Cd and As, whereas relatively poor for Cr and Fe. The daily airborne metal concentrations in 2015 were then predicted by the fully trained SVM models and the results showed the heaviest pollution of airborne heavy metals occurred in December and January, whereas the lightest pollution occurred in June and July.

To identify the sources of PM2.5 pollutants in work environments and determine whether the air quality inside an office was affected by a change in outdoor pollution status, concurrent indoor and outdoor measurements of PM2.5 were conducted at five different office spaces in the urban center of Guangzhou on low pollution days (non-episode days, NEDs), and high pollution days (haze episode days, EDs). Indoor-outdoor relationships between the PM2.5 mass and its chemical constituents, which included water-soluble ions, carbonaceous species, and metal elements, were investigated. A principle component analysis (PCA) was performed to further confirm the relationship between the indoor and outdoor PM2.5 pollution. The results reveal that (1) Printing and ETS (Environmental tobacco smoking) were found to be important office PM2.5 sources and associated with the enrichment of SO42-, OC, EC and some toxic metals indoors; (2) On EDs, serious outdoor pollution and higher air exchange rate greatly affected all studied office environments, masking the original differences of the indoor characteristics (3) Fresh air system could efficiently filter out most of the outside pollutants on both NEDs and EDs. Overall, the results of our study suggest that improper human behavior is associated with the day-to-day generation of indoor PM2.5 levels and sporadic outdoor pollution events can lead to poor indoor air quality in urban office environments. Moreover, fresh air system has been experimentally proved with data as an effective way to improve the air quality in office.

The present study was conducted to examine the potential mechanisms responsible for the distribution of polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (o-PAHs) in size fractionated particles and their environmental implications. Size-fractionated atmospheric particles were collected at urban Shanghai, China and analyzed for 5 PAHs and 6 o-PAHs. The concentrations of particle-bound ∑6o-PAHs (sum of 6 o-PAH congeners, 19.1 ± 4.5 ng m-3) were significantly higher than those of ∑5PAHs (sum of 5 PAHs, 9.5 ± 1.9 ng m-3). The size-fractionated distributions of airborne ∑5PAHs and ∑6o-PAHs displayed bimodal peaks at 0.7-1.1 and 9.0-10.0 μm. Emission sources and volatility were important factors influencing the size distribution of particle-bound 5 PAHs and 6 o-PAHs. The dry deposition fluxes of particle-bound 6 o-PAHs estimated from the measured data (3087 ± 467 ng m-2 d-1) were approximately 2 times higher than those of PAHs (1531 ± 344 ng m-2 d-1), with a total deposition flux of 4618 ± 743 ng m-2 d-1. The relative contributions of particles to dry deposition were also size-dependent, e.g., coarse (aerodynamic diameters (Dp) > 2.1 μm) particles dominated the dry deposition fluxes of PAHs and o-PAHs. These results highlight the significance of providing a comprehensive understanding of particle size distribution of PAHs and o-PAHs and their implication for dry deposition in China.

This paper describes the first results of a research project that aims to the development of a miniaturized atmospheric particulate matter sensor. The detector relies on a gravimetric selection of the particle size and on an integrated capacitive sensing interface. In this communication, in particular, preliminary results regarding the electronic readout are presented.

The correlation amongst exposure to ultrafine particle concentrations and heart rate in a large healthy population was investigated. The study was conducted by continuously monitoring for seven days fifty volunteers in terms of exposure to particle concentrations, heart rate and physical activity performed through portable monitors. Data were analyzed adopting a linear mixed model able to manage the obtained repeated measures and to recognize a general trend resulting from the subject-specific patterns. Results show that the short-term exposure to ultrafine particle concentrations is positively associated with the heart rate for the different physical activities of the subject investigated (laying down, sitting, standing positions). In particular, a logarithmic correlation was recognized with a sharper increase of about 4–6 bpm for a variation of the particle number concentration of 2 × 104 part/cm3 and a slighter effect for further increases of about 0.1–0.2 × 10−4 bpm/(part/cm). Capsule: A positive correlation can be associated between the exposure to ultrafine particles and the heart rate.

In the present study, the daily dose in terms of particle surface area received by citizens living in different low- and middle-income countries, characterized by different lifestyles, habits, and climates, was evaluated. The level of exposure to submicron particles and the dose received by the populations of Accra (Ghana), Cairo (Egypt), Florianopolis (Brazil), and Nur-Sultan (Kazakhstan) were analyzed. A direct exposure assessment approach was adopted to measure the submicron particle concentration levels of volunteers at a personal scale during their daily activities. Non-smoking adult volunteers performing non-industrial jobs were considered. Exposure data were combined with time-activity pattern data (characteristic of each population) and the inhalation rates to estimate the daily dose in terms of particle surface area. The received dose of the populations under investigation varied from 450mm2 (Florianopolis, Brazil) to 1300mm2 (Cairo, Egypt). This work highlights the different contributions of the microenvironments to the daily dose with respect to high-income western populations. It was evident that the contribution of the Cooking & Eating microenvironment to the total exposure (which was previously proven to be one of the main exposure routes for western populations) was only 8%-14% for low- and middle-income populations. In contrast, significant contributions were estimated for Outdoor day and Transport microenvironments (up to 20% for Cairo, Egypt) and the Sleeping & Resting microenvironment (up to 28% for Accra, Ghana), highlighting the effects of different site-specific lifestyles (e.g. time-activity patterns), habits, socioeconomic conditions, climates, and outdoor air quality.

Patients with airway symptoms working in metal working industries are increasing, despite efforts to improve the environmental air surrounding the machines. Our aim was to analyse the amount of endotoxin in size-separated airborne particles of metal working fluid (MWF) aerosol, by using the personal sampler Sioutas cascade impactor, to compare filter types, and to compare the concentration of airborne endotoxin to that of the corresponding MWFs. In a pilot field study, aerosols were collected in two separate machine halls on totally 10 occasions, using glass fibre and polytetrafluoroethylene (PTFE) filters in parallel at each station. Airborne endotoxin was distributed over all size fractions. While a major part was found in the largest size fraction (72%, 2.5-10 µm), up to 8% of the airborne endotoxin was detected in the smallest size fraction (

Different types of aerosolization and deagglomeration testing systems exist for studying the properties of nanomaterial powders and their aerosols. However, results are dependent on the specific methods used. In order to have well-characterized aerosols, we require a better understanding of how system parameters and testing conditions influence the properties of the aerosols generated. In the present study, four experimental setups delivering different aerosolization energies were used to test the resultant aerosols of two distinct nanomaterials (hydrophobic and hydrophilic TiO2). The reproducibility of results within each system was good. However, the number concentrations and size distributions of the aerosols created varied across the four systems; for number concentrations, e.g., from 103 to 106 #/cm3. Moreover, distinct differences were also observed between the two materials with different surface coatings. The article discusses how system characteristics and other pertinent conditions modify the test results. We propose using air velocity as a suitable proxy for estimating energy input levels in aerosolization systems. The information derived from this work will be especially useful for establishing standard operating procedures for testing nanopowders, as well as for estimating their release rates under different energy input conditions, which is relevant for occupational exposure. © 2015 American Association for Aerosol Research. Chemicals/CAS: titanium dioxide, 1317-70-0, 1317-80-2, 13463-67-7, 51745-87-0

Background The health effects of biological aerosols on the respiratory system are unclear. The purpose of this study was to clarify the association of airborne particle, protein, and endotoxin with emergency department visits for asthma in Kyoto City, Japan. Methods We collected data on emergency department visits at a hospital in Kyoto from September 2014 to May 2016. Fine (aerodynamic diameter ≤ 2.5 μm) and coarse (≥ 2.5 μm) particles were collected in Kyoto, and protein and endotoxin levels were analyzed. The association of the levels of particles, protein, endotoxin, and meteorological factors (temperature, relative humidity, wind speed, and air pressure) with emergency department visits for asthma was estimated. Results There were 1 to 15 emergency department visits for asthma per week, and the numbers of visits increased in the autumn and spring, namely many weeks in September, October, and April. Weekly concentration of protein in fine particles was markedly higher than that in coarse particles, and protein concentration in fine particles was high in spring months. Weekly endotoxin concentrations in fine and coarse particles were high in autumn months, including September 2014 and 2015. Even after adjusting for meteorological factors, the concentrations of coarse particles and endotoxin in both particles were significant factors on emergency department visits for asthma. Conclusions Our results suggest that atmospheric coarse particles and endotoxin are significantly associated with an increased risk of asthma exacerbation. Electronic supplementary material The online version of this article (10.1186/s12199-018-0731-2) contains supplementary material, which is available to authorized users.

Indoor and outdoor concentrations of PM2.5-associated perchlorate (ClO4(-)) and chlorate (ClO3(-)) were investigated in Jinan, China, and size-resolved perchlorate and chlorate were studied in Kumamoto, Japan. The average outdoor PM2.5-associated concentrations of perchlorate and chlorate were 4.18 ng m(-3) and 2.82 ng m(-3), respectively, in Jinan. Perchlorate and chlorate were mainly distributed in fine particles, and their approximate PM2.5-associated concentrations were 0.04 ng m(-3) and 4.14 ng m(-3), respectively, in Kumamoto. The ratios of ClO3(-)/ClO4(-) ranged from 18.72 to 360.22 in Kumamoto and from 0.03 to 7.45 in Jinan. The highest concentration of perchlorate (173.76 ng m(-3)) was observed on Spring Festival Eve. This finding and the significant correlation between perchlorate and fireworks-related components (Cl(-) and K(+)) indicated that the fireworks display was a significant source of perchlorate in Jinan. The indoor concentrations of perchlorate and chlorate in Jinan were 3.54 ng m(-3) (range, 0.14-125.14 ng m(-3)) and 0.94 ng m(-3) (range, 0.10-1.80 ng m(-3)), respectively. In the absence of an indoor source of perchlorate, the occurrence of indoor concentrations higher than those found outdoors was a common effect of individual fireworks displays near the sampling sites, coupled with meteorological influences and poor indoor diffusion conditions. The exposure risks of perchlorate and chlorate indoors indicated that the potential risk of perchlorate exposure to children during fireworks displays is deserving of concern.

Background Ambient coarse, fine, and ultrafine particles have been associated with mortality and morbidity. Few studies have compared how various particle size fractions affect systemic biomarkers. Objectives We examined changes of blood and urinary biomarkers following exposures to three particle sizes. Methods Fifty healthy nonsmoking volunteers, mean age of 28 years, were exposed to coarse (2.5–10 μm; mean, 213 μg/m3) and fine (0.15–2.5 μm; mean, 238 μg/m3) concentrated ambient particles (CAPs), and filtered ambient and/or medical air. Twenty-five participants were exposed to ultrafine CAP (< 0.3 μm; mean, 136 μg/m3) and filtered medical air. Exposures lasted 130 min, separated by ≥ 2 weeks. Blood/urine samples were collected preexposure and 1 hr and 21 hr postexposure to determine blood interleukin-6 and C-reactive protein (inflammation), endothelin-1 and vascular endothelial growth factor (VEGF; vascular mediators), and malondialdehyde (lipid peroxidation); as well as urinary VEGF, 8-hydroxy-deoxy-guanosine (DNA oxidation), and malondialdehyde. Mixed-model regressions assessed pre- and postexposure differences. Results One hour postexposure, for every 100-μg/m3 increase, coarse CAP was associated with increased blood VEGF (2.41 pg/mL; 95% CI: 0.41, 4.40) in models adjusted for O3, fine CAP with increased urinary malondialdehyde in single- (0.31 nmol/mg creatinine; 95% CI: 0.02, 0.60) and two-pollutant models, and ultrafine CAP with increased urinary 8-hydroxydeoxyguanosine in single- (0.69 ng/mg creatinine; 95% CI: 0.09, 1.29) and two-pollutant models, lasting < 21 hr. Endotoxin was significantly associated with biomarker changes similar to those found with CAPs. Conclusions Ambient particles with various sizes/constituents may influence systemic biomarkers differently. Endotoxin in ambient particles may contribute to vascular mediator changes and oxidative stress. Citation Liu L, Urch B, Poon R, Szyszkowicz M, Speck M, Gold DR, Wheeler AJ, Scott JA, Brook JR, Thorne PS, Silverman FS. 2015. Effects of ambient coarse, fine, and ultrafine particles and their biological constituents on systemic biomarkers: a controlled human exposure study. Environ Health Perspect 123:534–540; http://dx.doi.org/10.1289/ehp.1408387

In the present study, the daily dose in terms of particle surface area received by citizens living in five cities in Western countries, characterized by different lifestyle, culture, climate and built-up environment, was evaluated and compared. For this purpose, the exposure to sub-micron particle concentration levels of the population living in Barcelona (Spain), Cassino (Italy), Guilford (United Kingdom), Lund (Sweden), and Brisbane (Australia) was measured through a direct exposure assessment approach. In particular, measurements of the exposure at a personal scale were performed by volunteers (15 per each population) that used a personal particle counter for different days in order to obtain exposure data in microenvironments/activities they resided/performed. Non-smoking volunteers performing non-industrial jobs were considered in the study. Particle concentration data allowed obtaining the exposure of the population living in each city. Such data were combined in a Monte Carlo method with the time activity pattern data characteristics of each population and inhalation rate to obtain the most probable daily dose in term of particle surface area as a function of the population gender, age, and nationality. The highest daily dose was estimated for citizens living in Cassino and Guilford (>1000 mm2), whereas the lowest value was recognized for Lund citizens (around 100 mm2). Indoor air quality, and in particular cooking and eating activities, was recognized as the main influencing factor in terms of exposure (and thus dose) of the population: then confirming that lifestyle (e.g. time spent in cooking activities) strongly affect the daily dose of the population. On the contrary, a minor or negligible contribution of the outdoor microenvironments was documented.

Exposure to airborne particulate matter (PM) causes several diseases in the human body. The smaller particles, which have relatively large surface areas, are actually more harmful to the human body since they can penetrate deeper parts of the lungs or become secondary pollutants by bonding with other atmospheric pollutants, such as nitrogen oxides. The purpose of this study is to present the number of PM inhaled by subway users as a possible reference material for any analysis of the hazards to the human body arising from the inhalation of such PM. Two transfer stations in Seoul, Korea, which have the greatest number of users, were selected for this study. For 0.3–0.422 μm PM, particle number concentration (PNC) was highest outdoors but decreased as the tester moved deeper underground. On the other hand, the PNC between 1 and 10 μm increased as the tester moved deeper underground and showed a high number concentration inside the subway train as well. An analysis of the particles to which subway users are actually exposed to (inhaled particle number), using particle concentration at each measurement location, the average inhalation rate of an adult, and the average stay time at each location, all showed that particles sized 0.01–0.422 μm are mostly inhaled from the outdoor air whereas particles sized 1–10 μm are inhaled as the passengers move deeper underground. Based on these findings, we expect that the inhaled particle number of subway users can be used as reference data for an evaluation of the hazards to health caused by PM inhalation.

The reflectance of solar collecting mirrors can be significantly reduced by sand and dust soiling, particularly in arid environments. Larger airborne sand and dust particles can also cause damage by erosion, again reducing reflectance. This work describes investigations of the airborne particle size, shape, and composition in three arid locations that are considered suitable for CSP plants, namely in Iran, Libya, and Algeria. Sand and dust has been collected at heights between 0.5 to 2.0m by a variety of techniques, but are shown not to be representative of the particle size found either in ground dust and sand, or on the solar collecting mirror facets themselves. The possible reasons for this are proposed, most notably that larger particles may rebound from the mirror surface. The implications for mirror cleaning and collector facet erosion are discussed.

In the present study a mobile monitoring approach (i.e. bike with onboard instruments) was proposed and applied to investigate the spatial variability of all the key airborne particle metrics in an Italian urban area from a statistical point of view. Particle number, alveolar-deposited surface area, and PM10 concentrations were measured through hand-held monitors and compared to simultaneous background concentrations by means of non-parametric tests and further post-hoc tests (Kruskal-Wallis test). Streets characterized by exposure levels statistically higher than the background levels for all the particle metrics were identified for different seasons in a pilot urban area (Cassino, Italy). A higher number of hot spots was detected for metrics affected by ultrafine particles (i.e. number and alveolar-deposited surface area concentrations) with respect to PM10. The effect of metrological requirements of the instrumentation on the proposed method was also discussed.

Currently, there is a limited understanding of the sources of ambient fine particles that contribute to the exposure of children at urban schools. Since the size and chemical composition of airborne particle are key parameters for determining the source as well as toxicity, PM1 particles (mass concentration of particles with an aerodynamic diameter less than 1 µm) were collected at 24 urban schools in Brisbane, Australia and their elemental composition determined. Based on the elemental composition four main sources were identified; secondary sulphates, biomass burning, vehicle and industrial emissions. The largest contributing source was industrial emissions and this was considered as the main source of trace elements in the PM1 that children were exposed to at school. PM1 concentrations at the schools were compared to the elemental composition of the PM2.5 particles (mass concentration of particles with an aerodynamic diameter less than 2.5 µm) from a previous study conducted at a suburban and roadside site in Brisbane. This comparison revealed that the more toxic heavy metals (V, Cr, Ni, Cu, Zn and Pb), mostly from vehicle and industrial emissions, were predominantly in the PM1 fraction. Thus, the results from this study points to PM1 as a potentially better particle size fraction for investigating the health effects of airborne particles.

Exposure to fine particulate matter (PM2.5) is associated with a broad range of health risks. This study assessed the impacts of cooking smoke and environmental tobacco smoke on air quality at outdoor community events in Edmonton, Alberta (Canada). Data were collected at three festivals in July-August 2011 using a portable real-time airborne particle monitor. The pooled mean PM2.5 level was 12.41 μg/m(3). Peak readings varied from 52 to 1877 μg/m(3). Mean PM2.5 near food stalls was 35.42 μg/m(3), which exceeds the WHO limit for 24 h exposure. Mean PM2.5 levels with smokers present were 16.39 μg/m(3) (all points) and 9.64 μg/m(3) (excluding points near food stalls). Although some smokers withdrew from common spaces, on average 20 smokers/hour were observed within 3 m. Extending smoking bans would improve air quality and address related concerns. However, food preparation is a more pressing area for policy action to reduce PM2.5 exposure at these community events.

To date, few studies have focused on PM air quality in offices, despite the fact that a lot of people spend many working hours a day in such offices. The aim of the present study is to investigate PM1 and PM2.5 in offices in Milan (Northern Italy) and in the air outside those offices. The PM samples were analyzed to determine the entity of certain compounds with possible direct or indirect adverse effects on human health: PAHs, BpA, and water soluble inorganic ions.A good correlation between outdoor and indoor PM mass concentrations emerged (R2 ~0.87). The maximum I/O concentration ratio was 0.92, suggesting that the indoor PM level was always lower than the outdoor level. The average infiltration factor, FINF, was 0.55, showing that about a half of the outdoor PM had come indoors. The indoor-generated particles, Cig, had values ranging from 0 to 4.4 ?g m-3 (

The purpose of this study was to evaluate a potential risk of intraoperative contamination associated with clothing systems and surgeon’s motion in total joint replacement. The airborne particle concentrations at different locations around a single operating surgeon wearing standard surgical gown (SG) or modern “space suit” (SS) were compared. The particles in the size of ≥0.5 μm (roughly corresponding to a mean diameter of squamous epithelial cells) were counted at the following three locations: (1) ≈10 cm inferior to the wrist; (2) ≈10 cm posterior to the feet; and (3) near the chest (operative field) under condition either with or without the surgeon’s motion (stepping in place at ~1 Hz). The difference in the surgical clothing systems did not significantly affect the mean particle counts detected near the wrist and chest (p = 0.307 and 0.155, respectively). However, the particle count near the feet was 154 times higher in SS than SG (4630 ± 2795 vs. 30 ± 23 N/F3, p = 0.023). The simple stepping of the surgeon with SS increased contaminants near the chest 31 times as compared to the condition without motion (1053 ± 709 vs. 34 ± 31 N/F3, p = 0.0032). Although the particle count was less affected by the motion in SG than SS, contaminants near the chest increased ten times after the stepping in the use of SG (p = 0.032). The present results suggest that the intraoperative motion of a surgeon may considerably increase airborne particle/bacterial concentration in the operative field. This can be a much higher likelihood in SS rather than SG because of air blow-off from the incorporated cooling fan.

Airborne particulate monitoring is mandated as a component of good manufacturing practice. We present a procedure developed to monitor and interpret airborne particulates in an International Organization for Standardization (ISO) class 7 cleanroom used for the cell processing of Section 351 and Section 361 products.We collected paired viable and non-viable airborne particle data over a period of 1 year in locations chosen to provide a range of air quality. We used receiver operator characteristic (ROC) analysis to determine empirically the relationship between non-viable and viable airborne particle counts.Viable and non-viable particles were well-correlated (r(2) = 0.78), with outlier observations at the low end of the scale (non-viable particles without detectable airborne colonies). ROC analysis predicted viable counts ≥ 0.5/feet(3) (a limit set by the United States Pharmacopeia) at an action limit of ≥ 32 000 particles (≥ 0.5 µ)/feet(3), with 95.6% sensitivity and 50% specificity. This limit was exceeded 2.6 times during 18 months of retrospective daily cleanroom data (an expected false alarm rate of 1.3 times/year). After implementing this action limit, we were alerted in real time to an air-handling failure undetected by our hospital facilities management.A rational action limit for non-viable particles was determined based on the correlation with airborne colonies. Reaching or exceeding the action limit of 32 000 non-viable particles/feet(3) triggers suspension of cleanroom cell-processing activities, deep cleaning, investigation of air handling, and a deviation management process. Our full procedure for particle monitoring is available as an online supplement.

A series of experiments were conducted to evaluate characteristics of varied flooring types which may influence dirt buildup and airborne particle levels. The experiments included investigation of typical dirt loadings found on flooring in school environments, the time necessary to effectively vacuum dirt from textile flooring (both in chamber and school conditions), and the resuspension of particles generated from walking activity on various flooring types in chamber and classroom environments. The flooring types studied included textile floored surfaces (flow through (FT) carpet and variable cushion tufted textile (VCTT) floorings) and hard surface (vinyl composition tile (VCT)). The study demonstrates that dirt buildup on textile floors will vary based on the location within the classroom. One of the primary findings of the study is that textile floor covering in schools is not a homogeneous medium. Physical characteristics vary based on the type of backing, carpet tufted type, face weight, gauge (including stitches/inch), and adhesive requirements. This variance in physical parameters contributes to significant differences in the resuspension rates (RRs) of particles into the air, generated by walking activity. FT carpet displayed significantly greater (2.5–5 times) RRs than VCTT in both chamber conditions and classroom environments at similar floor loadings and particle size ranges. Controlled chamber test runs revealed VCT flooring exhibiting 3.6 time higher RRs than FT flooring and 12.8 time greater RRs than VCTT flooring. Moreover, particle RRs and airborne concentrations are also a function of time of walking activity, floor dust loadings and particle size ranges.

The number and mass distribution of airborne particles were recorded in several industrial plants. From the data obtained, particle deposition was estimated in three regions of the respiratory trac ...

The objective of this work is to carry out an experimental investigation on the influence of different parameters such as liquid properties (viscosity and liquid-gas surface tension), impacting droplet properties (velocity vi and diameter di) and the thickness of liquid film on the emission of airborne particles produced by the impact of millimetre-size droplets onto a liquid film. Our results show that in the variation range studied, the increase of vi and di or the decrease in liquid film thickness produces an increase in the mean number of microdroplets emitted by impact in the size range 2-50 μm. Furthermore, it was also observed that an increase in viscosity involves a steep decrease in the mean number of microdroplets emitted. These microdroplets may be produced by the fingers pinching of the crown formed during impact. In the case of low surface tension liquid, the formation of bubbles involves high production of droplets smaller than 15 μm. The results presented here constitute a database of the micro-droplets produced to validate models of droplet impact outcomes. © 2009 Elsevier Ltd. All rights reserved.

The objective of the study was to investigate size-selective concentrations of airborne particles and endotoxin in metalworking fluid (MWF) environments. The experiments were conducted under two conditions: (1) MWF collected in the field was aerosolized with a laboratory-scale simulator (MWF simulator) in the laboratory; and (2) MWFs were aerosolized during routine field operations. All experiments included size-selective measurement of airborne concentrations of particle numbers and endotoxin mass using an electrical low-pressure impactor. During field sampling, the total microbial and endotoxin concentrations in the air were also measured with a BioSampler, and the mass concentration of MWF mists was measured with a photometer. Airborne particle concentrations were highest in the fine particle size ranges in the areas affected by MWFs. Relatively high concentrations of endotoxin were detected at particle size below 0.39 mum, which is smaller than the size of intact bacterial cells. The total microbial and endotoxin analysis revealed high microbial contamination in one sampling site although the total particle mass was not elevated. It was concluded that MWF sites can be contaminated with high concentrations of fine particles, and these fine particles may contain microbial components, such as endotoxin. The results call for the size-selective measurement of particles and endotoxin for more comprehensive exposure assessment in MWF facilities.

The traceability of light-scattering airborne particle counter’s counting performance has received more attention, but has failed to settle internationally. This paper puts forward a traceability method of light-scattering airborne particle counter’s counting performance on single particle size, based on Anodic Aluminum Oxide (AAO) template andScanning Electron Microscope (SEM), by reforming the traditional standard airborne particle counter, building a measurement system including AAO and SEM, and utilizing the method of statistical physics in data processing to obtain more accurate measurement results. According to the actual test results and its uncertainty analysis, the traceability method of light-scattering airborne particle counter’s counting performance based on AAO and SEM makes sense in theory, and has certain research value on a solution to the traceability problem of light-scattering airborne particle counter internationally.

Different types of aerosolization and deagglomeration testing systems exist for studying the properties of nanomaterial powders and their aerosols. However, results are dependent on the specific methods used. In order to have well-characterized aerosols, we require a better understanding of how system parameters and testing conditions influence the properties of the aerosols generated. In the present study, four experimental setups delivering different aerosolization energies were used to test the resultant aerosols of two distinct nanomaterials (hydrophobic and hydrophilic TiO2). The reproducibility of results within each system was good. However, the number concentrations and size distributions of the aerosols created varied across the four systems; for number concentrations, e.g., from 103 to 106 #/cm3. Moreover, distinct differences were also observed between the two materials with different surface coatings. The article discusses how system characteristics and other pertinent conditions modify the test results. We propose using air velocity as a suitable proxy for estimating energy input levels in aerosolization systems. The information derived from this work will be especially useful for establishing standard operating procedures for testing nanopowders, as well as for estimating their release rates under different energy input conditions, which is relevant for occupational exposure. © 2015 American Association for Aerosol Research. Chemicals/CAS: titanium dioxide, 1317-70-0, 1317-80-2, 13463-67-7, 51745-87-0

For the assessment of doses after inhalation of airborne uranium compounds by workers, the International Commission on Radiological Protection (ICRP) developed compartmental models that are used to calculate reference dose coefficients and retention and excretion functions. It is assumed that each acute intake has no effect on the biokinetics of later intakes. Consequently, retention and excretion after multiple or chronic exposure are predicted using the same models as after acute exposure. This assumption was tested here on rats exposed to repeated inhalation of uranium dioxide (UO 2 ). First, excretion and organ retention were determined after a single inhalation of UO 2 . The follow-up of incorporated activity was used to design a biokinetic model for uranium inhaled by rats. Second, the biokinetics of uranium were monitored in two experiments of repeated inhalations of uranium dioxide under different intake patterns. For these two experiments, the organs' retention and excretion after repeated UO 2 inhalation were predicted using the biokinetic model and compared to the experimental measurement. Under the two sets of experimental conditions considered, the prediction of the biokinetic model based on acute exposure data was consistent with the biokinetics observed after repeated UO 2 inhalations, with the possible exception of retention in the skeleton. Copyright© Taylor & Francis Group, LLC.

Hollow-fiber flow field-flow fractionation (HF FlFFF) was applied for the separation and size characterization of airborne particles which were collected in a municipal area and prefractionated into four different-diameter intervals >5.0, 2.5-5.0, 1.5-2.5

In 2002 the Comité Européen Normalisation (CEN) published its document Workplace atmospheres-assessment of performance of instruments for measurement of airborne particle concentrations (EN 13205) that describes a standard protocol by which to carry out the testing and validation of personal aerosol samplers of the type widely used for occupational aerosol exposure assessment. It emerged from more than a decade of discussion and a large body of research experience involving several laboratories. The protocol that is described, however, still poses significant technical and economic challenges, not least because it involves laborious-and hence costly-procedures in large, specialized wind tunnel facilities. More recent research has identified a number of areas by which the protocol may be improved and made more accessible to testing laboratories, including a set of validated aerosol sampler scaling laws, a better understanding of the reduced role of the bluff body of the wearer on sampler performance, and the availability of new options for rapid sampler testing methods. Taking these into account, a dummy new protocol is offered for discussion.

Between 1991 and 2000, ambient air pollution in East Germany changed to resemble West German pollution levels: The concentration of total suspended particles (TSPs) decreased on a broad scale while traffic increased. During that time, we analyzed total lung capacity (TLC) and airway resistance (R(aw)) of East and West German children. We tested children 5-7 years of age (n = 2,574) with cooperation-independent body plethysmography in repeated cross sections. We used random-effect models to determine the mutually adjusted association between lung function and short-term and chronic particle exposure and its interaction with living near a busy road. Annual averages of TSPs declined from 77 to 44 microg/m2; averages on the day of investigation declined from 133 to 30 microg/m2. Differences in lung function between East and West German children vanished during the investigation time. The association of TSPs with R(aw) and TLC was stronger in children living > 50 m away from busy roads. East German children from this group had an R(aw) 2.5% higher [95% confidence interval (CI), 0.0-5.1%] per 40-microg/m2 increase of daily TSP averages. TLC decreased by 6.2% (95% CI, 0.04-11.6%) per 40-microg/m2 increase in annual mean TSPs, and this effect was equally pronounced in East and West Germany. TSP exposure decreased on a broad scale between 1991 and 2000. Lower concentrations of TSPs were associated with better measures of lung function in 6-year-old children. For children living near busy roads, this effect was diminished.

Laden et al. (2000) recently reported results of applying factor analysis to data taken in six cities from 1979 to 1988, identifying airborne particle sources potentially affecting daily mortality. These authors sought relationships between source groups and risk measures using source tracer elements, Se (coal combustion), Pb (light-duty motor vehicle sources), and Si (crustal--soil dispersion). Combined data analyses of this kind may overlook the complexity of source contributions, which have common tracer elements. In one of the cities, Boston, for example, the authors found coal combustion was an important source of mortality risk. For the city of Boston, the authors attribute coal combustion largely to distant upwind regional sources. The emphasis on coal combustion is confounded by the presence of major local sources of residual oil combustion, which contribute V, Se, and S (sulfur as sulfate) to the source apportionment. Evaluation of the source identification using single-element tracer analysis indicates that the detailed chemical composition or profile of major local sources needs to be taken into account in these investigations to minimize misclassification of airborne particle sources with potential adverse health effects.

International audience; The topic of this study is related to airborne particle dynamics in indoor environments. Lab-scale experiments have been performed to investigate particle deposition velocity to six different surfaces orientations (with respect to gravity) for fully developed turbulent flow in horizontal large circular ventilation ducts. Monodispersed aerosol particles (1–6 μm) were used in the deposition experiments. A very low particle mass (40 ng) was measured reliably above background level on duct surfaces by a means of a nondestructive stencil technique associated with fluorescence analysis. For 2–6 μm particles (diffusion and impaction regime), deposition rates to floors were much greater than rates to the ceiling and greater than rates to the wall. For 1-μm particles, the effect of surface orientation to particle deposition was not significant. Results were compared to the very few similar and published studies. This work was conducted in the frame of the CleanAirNet project which aimed at producing new knowledge, models, and techniques to help controlling the safety food stuffs, through a better control of aerosol particle (bioaerosols) transport and deposition in the ventilation networks of the food industry.

Background: Much of the evidence on the health effects of airborne particles is based on mortality and hospital admissions, while the evidence from other morbidity indicators is still limited. Objective: To measure the relationship between particles with diameter below 10 μm (PM10) and emergency ambulance dispatches (EAD). Methods: Daily EAD for six towns of the Emilia-Romagna region (Italy) were obtained from a database collecting real-time data. Time series analyses were performed, and city-specific estimates were combined using meta-analytic techniques. Results: We found a significant percentage change of EAD associated with a 10 μg/m3 increase of PM10 for non-traumatic diseases (0.86%, 95%CI: 0.61,1.1%). A positive relationship was also found for cardiovascular and respiratory diseases without reaching statistical significance. The risks were much higher in the warm (April-September) than in the cold season (January-March and October-December). Conclusions: Emergency ambulance dispatches provide useful insight into the health effects of air pollution and may be useful to establish surveillance systems. © W. S. Maney & Son Ltd 2014.

Ventilation duct serves as a potential target for bioterrorist attack. Understanding the dynamics of aerosolized harmful agents in the ventilation ducts provides the fundamentals for effective control and management, e.g., risk assessment. In this work, new models for predicting the concentration dynamics in the ventilation duct after a particle resuspension (representing the case that harmful agents are dosed when the ventilation is off and subsequently being turned on) or puff injection (representing the case that harmful agents are dosed when the ventilation is running) event were derived based on the mass balance model. The models were validated by a series of wind tunnel experiments. Indoor airborne particle concentration models were derived by incorporating the proposed ventilation duct models for resuspension and injection cases. The effects of resuspension and injection in the duct on indoor airborne particle concentration were examined by two hypothetical cases of Bacillus anthracis dosage using the derived models. For the same amount of BW agent dosage in the ventilation duct, the resuspension type release prolongs the exposure of harmful agents whereas the injection type release produces a higher peak concentration.

We installed an effective, practical and low-cost smoking corner in an office to protect against passive smoking. The smoking corner was separated from the non-smoking area with transparent, nonflammable screens. Four exhaust fans were installed in the smoking corner so that there was no leakage of environmental tobacco smoke. The required exhaust air rate in the smoking corner was pre-calculated from the volume of the smoking corner and the rate of consumption of cigarettes. The suspended airborne particle concentration definitely decreased in the non-smoking area after installation of the smoking corner. The result of a questionnaire survey also revealed the improvement in the air quality in this office.

The airborne particle and vapor phases of a volatile organic chemical (VOC) often coexist in the real workplace environment. Assessment of worker exposure to a VOC requires measuring not only the total airborne concentration but also the phase distribution because the deposition efficiency of the material in the respiratory tract will depend on the form in which it is inhaled. A prototype portable vapor/particle sampler (PVPS) has been designed for sampling and quantifying the phase distribution of volatile components in micrometer-sized airborne particles and coexisting gaseous phase based on differential inertia. The sampler was laboratory tested and validated. Tests included sampler performance assessment and comparison with current sampling methods for particles and organic vapors, i.e., glass fiber filter, charcoal sorbent tube, and diffusion monitors. The PVPS is a low-cost and lightweight device that can be driven by a single standard personal sampling pump. The mass quantities of materials collected by the sampler can be determined by standard analytical procedures. Combined with an appropriate size-selective inlet, the PVPS may be used as a personal inhalable or respirable volatile aerosol sampler for occupational VOC exposure assessment, especially in industrial, or household, spray work environments where the particle sizes are frequently large.

Part of a year-long study was to establish baseline measurements of airborne and surface dusts in a building. A four-story building was monitored with a laser particle counter (LPC) to characterize airborne particle size ranges of >0.5 to >15 m, a fine particle sampler (FPS) to measure 24-hour total airborne dust mass concentrations, and a high-volume small surface sampler (HVS3) to assess dust levels on floor surfaces. Monthly measurements were taken on each floor for 5 months. An improved cleaning regimen was instituted, and monitoring continued for 7 months. Mean LPC indoor particle counts correlated well with those outdoors (0.92). Mean LPC size distributions were similar on all floors, decreasing as particle size increased, and remained fairly constant over the study. FPS airborne dust mass concentrations were low throughout the building (5 to 11.5 g/m3). In comparing FPS and LPC measurements, mean 24-hour FPS total airborne dust mass measurements proved the most meaningful over a long term. LPC data...

Some of the superannuated equipment were replaced in the nuclear fuel reprocessing plant at the Tokai-works of the Power Reactor and Nuclear Fuel Development Corporation (PNC). The authors have been investigating the airborne particle sizes of radiological materials in the decommissioning process using Andersen samplers. This paper describes information on the particle sizes during the cutting processes. The activity median aerodynamic diameters (AMAD) of the aerosols ranged from 2 to 4μm, and their geometric standard deviations were in the range of approximately 2-3.

Many studies have focused their attention on the determination of elements of toxicological and environmental interest in atmospheric particulate matter using analytical techniques requiring chemical treatments. The instrumental nuclear activation analysis technique allows achieving high sensitivity, good precision, and excellent limit of detection without pretreatment, also considering the problems related to the radioisotope characteristics (e.g., half-life time, interfering reactions, spectral interferences). In this paper, elements such as Al, As, Br, Cl, Cu, I, La, Mg, Mn, Na, Sb, Si, Ti, and V are studied in atmospheric PM10 sampled in downtown Rome: The relative radionuclides after activation of the sample are characterized by very short (ranging from 2.24 to 37.2 min) and short (ranging from 2.58 h to 2.70 days) half-lives. Furthermore, As, Br, La, Mn, and Sb were also determined for evaluating the aerosol characteristics. The results, elaborated considering the matrix effects and the interfering reaction contribution to the radioisotope formation (e.g., (28)Al generated by both (n,γ) reaction from (27)Al and (n,p) reaction from (28)Si), show interesting values of As (0.3-6.1 ng m(-3)), Cu (22-313 ng m(-3)), Mn (17-125 ng m(-3)), V (7-63 ng m(-3)), higher than those determined in an area not influenced by autovehicular traffic, and significant levels of I (1-11 ng m(-3)) and Ti (25-659 ng m(-3)) in Rome PM10. The other elements show a pattern similar to the very few data present in the literature. It should be underlined the good correlation (r (2)) of Al vs. Mg (0.915) and Al vs. La (0.726), indicating a same sources for these species as well as Br-Sb showing a little lower correlation (0.623). This last hypothesis is confirmed by the study of the enrichment factors: Sb and Br may be attributed to anthropogenic sources; Cu, Cl, and I show a mixed origin (natural and anthropogenic), whereas Al, Si, Ti, Mn, Na, Mg, and As are of crustal origin. For having more information, a statistical approach based on the principal component analysis and the canonical discriminant analysis has been performed: All the samples (except one) are grouped in a cluster, and elements such as As, Br, Cu, I, La, Mn, Sb, Ti, and V are highly correlated, whereas Na and Cl and Mg and Al assemble in two different clusters. Finally, a comparison with other similar studies is reported showing interesting values for Al, As, Mg, Mn, and Ti.