scholarly journals Particle Concentrations in Occupational Settings Measured with a Nanoparticle Respiratory Deposition (NRD) Sampler

2018 ◽  
Vol 62 (6) ◽  
pp. 699-710 ◽  
Author(s):  
Larissa V Stebounova ◽  
Natalia I Gonzalez-Pech ◽  
Jae Hong Park ◽  
T Renee Anthony ◽  
Vicki H Grassian ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Metal Particles ◽  
Heavy Vehicle ◽  
Breathing Zone ◽  
Shooting Range ◽  
Diffusion Stage ◽  
Respiratory Deposition ◽  
Iron Foundry ◽  
Respirable Mass Concentration ◽  
Occupational Settings

Abstract There is an increasing need to evaluate concentrations of nanoparticles in occupational settings due to their potential negative health effects. The Nanoparticle Respiratory Deposition (NRD) personal sampler was developed to collect nanoparticles separately from larger particles in the breathing zone of workers, while simultaneously providing a measure of respirable mass concentration. This study compared concentrations measured with the NRD sampler to those measured with a nano Micro Orifice Uniform-Deposit Impactor (nanoMOUDI) and respirable samplers in three workplaces. The NRD sampler performed well at two out of three locations, where over 90% of metal particles by mass were submicrometer particle size (a heavy vehicle machining and assembly facility and a shooting range). At the heavy vehicle facility, the mean metal mass concentration of particles collected on the diffusion stage of the NRD was 42.5 ± 10.0 µg/m3, within 5% of the nanoMOUDI concentration of 44.4 ± 7.4 µg/m3. At the shooting range, the mass concentration for the diffusion stage of the NRD was 5.9 µg/m3, 28% above the nanoMOUDI concentration of 4.6 µg/m3. In contrast, less favorable results were obtained at an iron foundry, where 95% of metal particles by mass were larger than 1 µm. The accuracy of nanoparticle collection by NRD diffusion stage may have been compromised by high concentrations of coarse particles at the iron foundry, where the NRD collected almost 5-fold more nanoparticle mass compared to the nanoMOUDI on one sampling day and was more than 40% different on other sampling days. The respirable concentrations measured by NRD samplers agreed well with concentrations measured by respirable samplers at all sampling locations. Overall, the NRD sampler accurately measured concentrations of nanoparticles in industrial environments when concentrations of large, coarse mode, particles were low.

scholarly journals Chemical characterization of the inorganic fraction of aerosols and mechanisms of the neutralization of atmospheric acidity in Athens, Greece

2006 ◽  
Vol 6 (6) ◽  
pp. 12389-12431
Author(s):  
E. T. Karageorgos ◽  
S. Rapsomanikis ◽  
P. Wåhlin
Keyword(s):  
Mass Concentration ◽  
Major Ions ◽  
Fine Fraction ◽  
Ambient Air ◽  
Coarse Fraction ◽  
Particle Mass ◽  
Molar Ratio ◽  
Breathing Zone ◽  
Predominant Component ◽  
Neutralizing Agent

Abstract. Mass concentration levels and the inorganic chemical composition of PM10 (two fractions; PM10−2.5 and PM2.5) were determined during August 2003 and March 2004, in the centre of Athens, Greece. August 2003 monthly mean PM10 mass concentration, at 5 m above ground, was 56 μg/m3 and the EU imposed daily limit of 50 μg/m3 was exceeded on 16 occasions. The corresponding monthly mean for March 2004 was 92 μg/m3 and the aforementioned daily limit was exceeded on 23 occasions. The PM10 (PM10−2.5+PM2.5) mass concentrations at 1.5 m above ground were found to be approximately 20% higher compared to the respective PM10 measured at 5 m. Consequently, for a realistic estimation of the exposure of citizens to particulate matter, PM10 sampling at a height of 1.5–3 m above ground, in the "breathing zone" is necessary. Such data are presented for the first time for the centre of Athens. In both campaigns, calcium was found to be the predominant component of the coarse fraction while crust-related aluminosilicates and iron were found to be the other major components of the same fraction. The above elements constitute the most important components of the fine fraction, together with the predominant sulphur. Toxic metals were found to be below the air quality limits and in lower concentrations compared to older studies, with the exception of Cu and V for which some increase was observed. Pb, in particular, appeared mostly in the fine fraction and in very low concentrations compared to studies dating more than a decade back. The major ions of the coarse fraction have been found to be Ca2+, NO3− and Cl−, while SO4−2, Ca2+ and NH4+ were the major ionic components of the fine fraction. The low molar ratio of NH4+/SO4−2 indicated an ammonium-poor ambient air, where atmospheric ammonia is not sufficient to neutralize all acidity and the formation of NH4NO3 does not occur to a significant extend. Calcium predominated the coarse fraction and its good correlations with NO3− and SO4−2 indicated its role as an important neutralizing agent of atmospheric acidity in this particle size range. In the fine fraction, both Ca2+ and NH4+ participate in the neutralizing processes with NH4+ being the major neutralizing agent of SO4−2. Chloride depletion from NaCl or MgCl2 was not found to occur to a significant extend. Total analyzed inorganic mass (elemental+ionic) was found to be ranging between approximately 25–33% of the total coarse particle mass and 35–42% of the total fine particle mass.

scholarly journals Chemical characterization of the inorganic fraction of aerosols and mechanisms of the neutralization of atmospheric acidity in Athens, Greece

2007 ◽  
Vol 7 (11) ◽  
pp. 3015-3033 ◽  
Author(s):  
E. T. Karageorgos ◽  
S. Rapsomanikis
Keyword(s):  
Mass Concentration ◽  
Fine Fraction ◽  
Ambient Air ◽  
Coarse Fraction ◽  
Particle Mass ◽  
Coarse Particle ◽  
Breathing Zone ◽  
Neutralizing Agent ◽  
Pm10 Mass ◽  
Mass Concentrations

Abstract. The PM10 mass concentration levels and inorganic chemical composition were determined on 12-h resolution sampling during August 2003 and March 2004, in the centre of Athens, Greece. The August 2003 campaign mean PM10 mass concentration, obtained by Beta Attenuation at 5 m above ground in Athinas Street, was 56 μg m−3 while the corresponding value for March 2004 was 92 μg m−3. In both campaigns the E.U. imposed daily limit of 50 μg m−3 was exceeded on several days. During the March campaign, in Athinas Street, additionally obtained DSFU-PM10 (PM10-2.5+PM2.5) gravimetric mass concentrations (mean: 121 μg m−3) in the "breathing zone", at 1.5 m above ground were significantly higher compared to the respective mean PM10 mass concentrations obtained by the same method at 25 m above ground, in a second site (AEDA; mean: 86 μg m−3) also in the centre of the city. The above findings suggest that, for a realistic estimation of the exposure of citizens to particulate matter, PM10 sampling in the "breathing zone" (1.5–3 m above ground) is necessary. Such data are presented for the first time for the centre of Athens. In both campaigns, calcium was found to be the predominant component of the coarse fraction while crust-related aluminosilicates and iron were the other major components. The above elements constitute the most important components of the fine fraction, together with the predominant sulphur. All toxic metals were found in concentrations below the established air quality limits, and most of them in lower concentrations compared to older studies. Lead in particular, appeared mostly in the fine fraction and in very low concentrations compared to studies dating more than a decade back. The predominant ions of the coarse fraction have been found to be Ca2+, NO3−, Na+ and Cl−, while SO42−, Ca2+ and NH4+ were the major ionic components of the fine fraction. In the fine particles, a low molar ratio of NH4+/SO42− indicated an ammonium-poor ambient air, and together with inter-ionic correlations suggested that atmospheric ammonia is the major neutralizing agent of sulfate, while being insufficient to neutralize it to full extend. The formation of NH4NO3 is therefore not favored and additional contribution to the neutralization of acidity has been shown to be provided by Ca2+ and Mg2+. In the coarse particle fraction, the predominantly abundant Ca2+ has been found to correlate well with NO3− and SO42−, indicating its role as important neutralizing agent in this particle size range. The proximity of the location under study to the sea explains the important concentrations of salts with marine origin like NaCl and MgCl2 that were found in the coarse fraction, while chloride depletion in the gaseous phase was found to be limited to the fine particulate fraction. Total analyzed inorganic mass (elemental+ionic) was found to be ranging between approximately 25–33% of the total coarse particle mass and 35–42% of the total fine particle mass.

Toxic trace metals in size-segregated fine particulate matter: Mass concentration, respiratory deposition, and risk assessment

2020 ◽  
Vol 266 ◽  
pp. 115242 ◽  
Author(s):  
Sabrina Rovelli ◽  
Andrea Cattaneo ◽  
Winfried Nischkauer ◽  
Francesca Borghi ◽  
Andrea Spinazzè ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Particulate Matter ◽  
Trace Metals ◽  
Mass Concentration ◽  
Fine Particulate Matter ◽  
Fine Particulate ◽  
Respiratory Deposition ◽  
Toxic Trace Metals

scholarly journals Laboratory Investigations Applied to Wood Dust Emmited by Electrical Hand-Held Belt Sander

2018 ◽  
Vol 26 (3) ◽  
pp. 133-136 ◽  
Author(s):  
Miroslav Dado ◽  
Lucia Mikušová ◽  
Richard Hnilica
Keyword(s):  
Wood Species ◽  
Mass Concentration ◽  
Beech Wood ◽  
European Beech ◽  
Grit Size ◽  
Wood Dust ◽  
Breathing Zone ◽  
Significance Level ◽  
Fagus Sylvatica L ◽  
Full Factorial

Abstract Aim of this paper was to investigate the effects of grit size and wood species on mass concentration and size distribution of wood dust produced by hand-held belt sander. Experimental study was designed as 2x2 full factorial experiments. Experimental parameters and their levels were abrasive grain size (P80, P120) and wood species (European beech (Fagus sylvatica L.), Norway spruce (Picea abies)).The mass concentration of emitted wood dust was measured using aerosol monitor (TSI Inc., DustTrak DRX 8533). Sampler head was sited in place representing breathing zone of operator of sander. The results was analysed employing the analysis of variance (ANOVA) with 5% of significance level. Real-time measurements demonstrated that spruce wood generated higher dust concentrations than beech wood due to difference in abrasion durability. Compared to sanding belt with P80 grit size, approximately 16%-32% higher dust concentration was generated when the sanding belt with P120 grit size was used.

scholarly journals Carboxylesterase Concentration in Mouse Exposed to Particulate Matters on Inhalation Exposure of Prallethrin and d-Phenothrin Mixture

2019 ◽  
Vol 125 ◽  
pp. 04006
Author(s):  
Indri Santiasih ◽  
Harmin Sulistiyaning Titah ◽  
Joni Hermana
Keyword(s):  
Ultrafine Particles ◽  
Mass Concentration ◽  
High Surface ◽  
High Surface Area ◽  
Inhalation Exposure ◽  
Positive Control ◽  
Number Concentration ◽  
Particulate Matters ◽  
Breathing Zone ◽  
Living Organisms

CE enzyme applied critical hydrolysis of pyrethroid families such as prallethrin and d-phenothrin, this active ingredient was commonly contained in mosquito repellent (MR). The previous study found that MRs as particulate matters (PMs) were very hazardous for living organisms due to the characteristics of number and mass concentration. This study examined the CE concentration in Mus musculus exposed to PM on inhalation exposure of prallethrin and d-phenothrin mixture. The lower dose was a mixture of 0.000141 mg/L prallethrin and 0.104 mg/L d-phenothrin, while the higher dose was a mixture of 0.00141 mg/L prallethrin and 1.04 mg/L d-phenothrin. Prallethrin and d-phenothrin were dissolved in acetonitrile, then diluted several times to obtain the preferred concentration. The solution was inflated with air through a diffuser to generate PMs which inserted into the chamber contained mice. The experimental group was divided into three, namely: positive control (PC), and lower- and higher-dose treatment groups, with three replicates for each group. The results illustrate that lower and higher dose demonstrated major differences. The statistical analysis confirmed that CE concentration had significant differences between groups. The increase in pyrethroid concentration followed by the increase of CE concentration, It indicated that the increasing CE substrates would be followed by the increasing of protein synthesis including CE. PMs in terms of number concentration of the largest (particles/L) is 0.3 µm, followed by 0.5 µm, 1 µm, and 5 µm. Approximately 99.86 % of the mass concentration the breathing zone is contributed by respirable particles (fine and ultrafine particles). Even if ultrafine particles are the largest number concentration, they have no significant contributions to the mass. A very abundant of fine and ultrafine particles affects they were beyond detection limit instruments, thus, they have no significant relationship with CE concentration, even though number concentration is more prominent than the mass concentration in the toxicological field, due to the high surface area of ultrafine particles.

scholarly journals Influence of Heat Treatments, Parameters and Machining Conditions on Machinability in the Turning of Recycled 6061 Aluminum Alloy

2021 ◽  
Vol 5 (2) ◽  
pp. 37
Author(s):  
Jean Brice Mandatsy Moungomo ◽  
Guy Richard Kibouka ◽  
Donatien Nganga-Kouya
Keyword(s):  
Aluminum Alloys ◽  
Predictive Models ◽  
Mass Concentration ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Cutting Parameters ◽  
Metal Particles ◽  
Manufacturing Companies ◽  
6061 Aluminum Alloy ◽  
Material Hardness

Some manufacturing companies now use recycled aluminum alloys. It is important that they have the necessary data relating to the control of the machinability of these alloys. Thus, this study on the machinability in the turning of two recycled aluminum alloys by a 6061 R and 6061 R-T6 smelter was conducted. The aim of this study is to provide solutions to the problem posed, which is whether recycled aluminum alloys have good machinability skills, such as virgin aluminum alloys. To provide these solutions, the experimental designs were used to study the influence of cutting parameters and conditions (feed, cutting speed, lubrication) and material hardness on machinability characteristics (surface roughness, mass concentration of metal particles, and chip morphology). The results of this study show that the two alloys studied have good machinability. The feed, hardness and lubrication significantly influence the machinability of these two alloys. Predictive models to assess the machinability of these recycled alloys have been established.

scholarly journals Effect of Puffing Behavior on Particle Size Distributions and Respiratory Depositions From Pod-Style Electronic Cigarette, or Vaping, Products

2021 ◽  
Vol 9 ◽  
Author(s):  
Anand Ranpara ◽  
Aleksandr B. Stefaniak ◽  
Elizabeth Fernandez ◽  
Ryan F. LeBouf
Keyword(s):  
Particle Size ◽  
Electronic Cigarette ◽  
Fourth Generation ◽  
Head Region ◽  
Aerosol Mass ◽  
Modifiable Factors ◽  
Respiratory Deposition ◽  
Aerosol Particle Size ◽  
Exposure Potential ◽  
Occupational Settings

The current fourth generation (“pod-style”) electronic cigarette, or vaping, products (EVPs) heat a liquid (“e-liquid”) contained in a reservoir (“pod”) using a battery-powered coil to deliver aerosol into the lungs. A portion of inhaled EVP aerosol is estimated as exhaled, which can present a potential secondhand exposure risk to bystanders. The effects of modifiable factors using either a prefilled disposable or refillable pod-style EVPs on aerosol particle size distribution (PSD) and its respiratory deposition are poorly understood. In this study, the influence of up to six puff profiles (55-, 65-, and 75-ml puff volumes per 6.5 and 7.5 W EVP power settings) on PSD was evaluated using a popular pod-style EVP (JUUL® brand) and a cascade impactor. JUUL® brand EVPs were used to aerosolize the manufacturers' e-liquids in their disposable pods and laboratory prepared “reference e-liquid” (without flavorings or nicotine) in refillable pods. The modeled dosimetry and calculated aerosol mass median aerodynamic diameters (MMADs) were used to estimate regional respiratory deposition. From these results, exhaled fraction of EVP aerosols was calculated as a surrogate of the secondhand exposure potential. Overall, MMADs did not differ among puff profiles, except for 55- and 75-ml volumes at 7.5 W (p < 0.05). For the reference e-liquid, MMADs ranged from 1.02 to 1.23 μm and dosimetry calculations predicted that particles would deposit in the head region (36–41%), in the trachea-bronchial (TB) region (19–21%), and in the pulmonary region (40–43%). For commercial JUUL® e-liquids, MMADs ranged from 0.92 to 1.67 μm and modeling predicted that more particles would deposit in the head region (35–52%) and in the pulmonary region (30–42%). Overall, 30–40% of the particles aerosolized by a pod-style EVP were estimated to deposit in the pulmonary region and 50–70% of the inhaled EVP aerosols could be exhaled; the latter could present an inhalational hazard to bystanders in indoor occupational settings. More research is needed to understand the influence of other modifiable factors on PSD and exposure potential.

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