Wyniki wyszukiwania - Biblioteka Nauki

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Exposure to diesel exhaust fumes in the context of exposure to ultrafine particles

100%

Bujak-Pietrek S. , Mikołajczyk U. , Kamińska I. , Cieślak M. , Szadkowska-Stańczyk I.

International Journal of Occupational Medicine and Environmental Health

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2016

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tom 29

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nr 4

667-682

EN

Objectives Diesel exhaust fumes emission is a significant source of ultrafine particles, the size of which is expressed in nanometers. People occupationally exposed to diesel exhaust particles include mainly workers servicing vehicles with engines of this type. This article presents the analysis of measurements of ultrafine particle concentrations occurring in the bus depot premises during the work connected with everyday technical servicing of buses. Material and Methods The measurements were carried out in the everyday servicing (ES) room of the bus depot before, during and after the work connected with bus servicing. Determinations included: particle concentrations in terms of particle number and particle surface area, and mass concentrations of aerosol. Results Mean value of number concentration of 10- to 1000-nm particles increased almost 20-fold, from 7600 particles/cm³ before starting bus servicing procedures to 130 000 particles/cm³ during the bus servicing procedures in the room. During the procedures, the mean surface area concentration of particles potentially deposited in the alveolar (A) region was almost 3 times higher than that of the particles depositing in the tracheo-bronchial (TB) region: 356.46 μm²/cm³ vs. 95.97 μm²/cm³, respectively. The mass concentration of the fraction of particulate matter with aerodynamic diameter 0.02–1 μm (PM₁) increased 5-fold during the analyzed procedures and was 0.042 mg/m³ before, and 0.298 mg/m³ while the procedures continued. Conclusions At the time when bus servicing procedures continued in the ES room, a very high increase in all parameters of the analyzed particles was observed. The diesel exhaust particles exhibit a very high degree of fragmentation and, while their number is very high and their surface area is very large, their mass concentration is relatively low. The above findings confirm that ultrafine particles found in diesel exhaust fumes may be harmful to the health of the exposed people, and to their respiratory tract in particular.

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Transmission of ultrafine particles through separating systems of dust samplers

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Skubacz K.

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tom Vol. 17, iss. 2

48--55

EN

In underground mines there is a radiation hazard associated with natural radioactive nuclides. The main sources of radiation exposure in Polish mines are short-lived radon decay products, radioactive mine water containing radium and the sediments precipitated from these waters. For miners, the most common hazard is usually the short-lived radon decay products. Aspirators, equipped with separation systems, are mostly used in order to control this hazard. Inside these aspirators there are meters which measure the radiation emitted by radioactive aerosols collected on the filter. The purpose of these systems is to remove particles from the air stream that do not form the respirable fraction. At the same time, however, a deposition of small-size aerosols takes place in them because of the high values of their corresponding diffusion coefficients. This excludes the possibility of their proper detection by radiation meters. In this paper, the transmission of particles up to 100 nm in size by the separating systems is evaluated. The evaluated transmission ranged from about 60% for sizes of 7 nm, reaching up to 95% at the boundary values of the tested range. The influence of the particle distribution of the aerosols on the radiation calibration coefficients was also investigated in a radon chamber, through their exposure to conditions where the air contained low aerosol concentrations of about 4.0×108 particles/m3 and also when it was nearly 100-times higher. In the first case, the measured sensitivity of the meters was about 20-30% lower, which was probably due to a higher number of small aerosols and, as a result, particle transmission decreased. However, at higher aerosol concentrations, the sensitivity of the meters remained practically the same, regardless of whether the air reached the filters by the separation systems or if they were omitted.

3

Non-regulated emissions and particle number emissions of two passenger cars with diesel-butanol blends

84%

Engelmann D. , Comte P. , Czerwinski J. , Renz S. , Bonsack P.

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tom R. 59, nr 4

29--38

EN

Biofuels represent one of the alternatives to obtain the CO2 - neutral propulsion of IC-engines. Butanol, which can be produced from biomass, is considered and was investigated in the last years due to the very advantageous characteristics of this alternative fuel. Butanol can be easily and irreversibly blended both with light (gasoline) and heavier (diesel) fuels. Comparing with ethanol it has the advantages of: higher calorific value, lower hygroscopicity and lower corrosivity. It can replace the aviation fuels. This paper presents the emission results obtained on two diesel passenger cars with different technology (Euro 2 and Euro 6c) and with addition of butanol to diesel fuel, as a part of the research project DiBut (diesel and butanol). Interesting results are given about some non-legislated (non-regulated) components, acetaldehyde (MeCHO) and formaldehyde (HCHO) and about the PN-emissions with/without DPF.

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One-year-long, comprehensive analysis of pm number and mass size distributions in Warszawa (Poland)

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Bihałowicz J. S. , Rogula-Kozłowska W. , Rogula-Kopiec P. , Świsłowski P. , Rajfur M. , Tomasz O.

Ecological Chemistry and Engineering. S

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2023

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tom Vol. 30, nr 4

541--556

EN

The properties of particulate matter PM, including its impact on the environment and human health, depend mainly on the size (more precisely: size distribution) of the particles since the size is usually dependent on the processes/sources of the PM. This work presents the results of a one-year-long measurement campaign of PM. PALAS Fidas 200 from Airpointer air quality station was used. The PM was measured in Warsaw, Poland continuously from 1st May 2022 to 30th April 2023; size distribution was recorded with 120 s intervals and averaged in 3600 s periods. It was found, that the number and the mass size distribution varied depending on the averaging period (different hours of the day, different days of the week, and different months of the year). Additionally, the authors determined the periods of impact on selected sources (traffic emission, municipal emission, and industrial emission) on the number and mass size distributions of PM at the sampling site. Monitoring of number and mass size distributions of PM is a relatively easy and more cost-effective method than analysing the chemical composition of PM. Therefore, is crucial to develop a method of identifying sources of PM based on size distributions. It was found that such a method can be in the future as successful in source apportionment as in the analysis of chemical compositions.

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Measurements of aerosol size distribution in urban areas of Upper Silesia

67%

Skubacz K.

Archives of Environmental Protection

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2009

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tom Vol. 35, no. 4

23-34

EN

Deposition of aerosols in the respiratory tracts depends on their size distribution. Investigation of such distribution has therefore great meaning for appropriate assessment of risk caused by hazardous pollutants that appear in environment both as a result of human activities like industry, emission from motor vehicles, municipal emission due to house furnaces and natural phenomena. The results of screening measurements of size distribution performed in several places located on highly populated areas in Upper Silesia, Poland are described in this paper. The applied equipment makes it possible to cover the range from several nanometers up to 20 žm, practically all particles that belong to the respirable class. Obtained results prove that a lot of particles having a size of the order of submicrons are produced close to high density traffic roads. This concentration strongly changed in time.

PL

Depozycją aerozoli w układzie oddechowym zależy od rozkładu ziarnowego aerozoli. Badanie rozkładu ma zatem duże znaczenie dla właściwej oceny zagrożenia spowodowanego przez szkodliwe substancje pojawiające się w środowisku bądź to w następstwie ludzkiej aktywności takiej jak produkcja przemysłowa, komunikacja i paleniska domowe bądź też w wyniku naturalnych procesów. W pracy opisano i oceniono wyniki pilotażowych pomiarów rozkładów ziarnowych aerozoli wykonanych w kilku miejscach zlokalizowanych na terenach zurbanizowanych. Zastosowana aparatura pomiarowa umożliwiała wykonanie badań rozkładów ziarnowych w szerokim zakresie od kilku nanometrów do 20 žm obejmującym praktycznie całą frakcję cząstek respirabilnych. Uzyskane rezultaty wskazują, że w miejscach położonych blisko dróg o dużym natężeniu ruchu pojawiają się duże liczny nanometrowych aerozoli, których liczba ulega w czasie dużym wahaniom