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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

2016

vol. 29

issue 4

667-682

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.

Evaluation of biological effects of nanomaterials. Part I. Cyto- and genotoxicity of nanosilver composites applied in textile technologies

86%

Wąsowicz W., Cieślak M., Palus J., Stańczyk M., Dziubałtowska E., Stępnik M., Düchler M.

International Journal of Occupational Medicine and Environmental Health

2011

vol. 24

issue 4

348-358

Objectives: The aim of this study was to investigate the cyto- and genotoxicity of nanocomposites (NCs) and generation of reactive oxygen species (ROS) as a result of particle-cell interactions. Materials and Methods: Titanium dioxide (TiO₂-Ag) and ion-exchange resin (Res-Ag), both coated with silver (Ag), were examined. The murine macrophage J774A.1 cells were incubated in vitro with NC at different concentrations for 24 h. Cytotoxicity was analyzed by the methylthiazolyldiphenyltetrazolium bromide reduction test (MTT reduction test). ROS generation was assessed by incubation of cells with dichlorodihydrofl uorescein diacetate (DCF) and fl ow cytometry. DNA damage was detected by comet assay and included single-strand breaks (SSB), alkali-labile sites (ALS) and oxidative DNA damage after formamidopyrimidine glycosylase (FPG) treatment. The tail moment was used as an indicator of DNA damage. Results: TiO₂-Ag was not cytotoxic up to 200 μg/ml, whereas IC₅₀ for Res-Ag was found to be 23 μg/ml. Intracellular ROS levels were elevated after 4 h of exposure to Res-Ag at the concentration of 50 μg/ml. Both types of NC induced fragmentation of DNA strands, but only one of the composites caused damage to purine bases. TiO₂-Ag induced SSB of DNA at concentrations of 10 and 5 μg/ml. For Res-Ag, a concentration-dependent increase in tail moments was observed. Conclusions: Silver-coated nanocomposites (both TiO₂- Ag and Res-Ag) may cause genotoxic effects in murine macrophages J774A.1. Res-Ag increased generation of ROS which suggested that toxicity of Res-Ag in murine macrophages is likely to be mediated through oxidative stress. This paper will support industry and regulators alike in the assessment of hazards and risks and methods for their mitigation at the earliest possible stage in material and product development.

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2 International Journal of Occupational Medicine and Environmental Health

2 Cieślak M.

1 Bujak-Pietrek S.

1 Dziubałtowska E.

1 Düchler M.

1 Kamińska I.

1 Mikołajczyk U.

1 Palus J.

1 Stańczyk M.

1 Stępnik M.

1 Szadkowska-Stańczyk I.

1 Wąsowicz W.

1 2016

1 2011

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

Evaluation of biological effects of nanomaterials. Part I. Cyto- and genotoxicity of nanosilver composites applied in textile technologies