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

Abstract

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/cm 3 before starting bus servicing procedures to 130 000 particles/cm 3 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 μm 2 /cm 3 vs. 95.97 μm 2 /cm 3 , respectively. The mass concentration of the fraction of particulate matter with aerodynamic diameter 0.02-1 μm (PM 1 ) increased 5-fold during the analyzed procedures and was 0.042 mg/m 3 before, and 0.298 mg/m 3 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 exposure to nano-sized particles among transport and vehicle service workers

“…In this research, the concentration of the alveolar fraction particles was at the level of 356 μm 2 /cm 3 and that of the tracheo-bronchial fraction at the level of 96 μm 2 /cm 3 , while the buses were riding through DSH in the bus depot. Those values were higher than in the present study but the measurement was done using the apparatus measuring particles in a wider measuring scope (i.e., sizes 10-1000 nm) [6].…”

“…As revealed by the values obtained in one of these studies [24], focused on particles ranging 10-500 nm, the number concentration was 3.9×10 5 p/cm 3 . In real conditions of particles emissions from vehicles: in car repair workshops [26], during the construction of road tunnels [27], at a bus depot [6], and in the road traffic or near busy streets [3], the concentration values were at quite different levels because of the diversity of places and different equipment used by the researchers. Nonetheless, the results of all measurements showed evident differences in the number of airborne particles emitted from vehicle engines.…”

“…Increased particle emissions occur with poorly heated engines, especially during the so-called cold start. Particles released by diesel engines are mostly fine particles, especially PM 2.5 -a fraction containing mainly nanoparticles sized <0.1 μm [5,6]. The estimated size of particles emitted by petrol engines ranged 20-60 nm [5,7].…”

Impact of diesel exhaust particles on infections with Mycobacterium bovis BCG in in vitro human macrophages and an in vivo Galleria mellonella model

“…Diesel exhaust fumes are a main contributor to urban contamination and operators of excavators, cranes, forklift trucks, workers at bus depots, car mechanics, railway workers or miners, are especially exposed ( Hart et al, 2012 ). Occupational exposure is an important risk factor for chronic obstructive pulmonary disease (COPD); however, not only people at work are at risk, since diesel exhaust is dispersed by transport vehicles such as buses, cars, trains, and especially trucks, it results in air contamination in urban environments ( Bujak-Pietrek et al, 2016 ). In the past rapid industrialization increased the health risk to humans in urban areas ( Kim et al, 2019 ).…”

“…Additionally, exhaust gas can condense and form ultrafine particles that can be grouped and aggregate to 15–40 nm particles. The small size of these particles means they can very easily get into the respiratory tract, where they can reach the alveoli ( Bujak-Pietrek et al, 2016 ; Rodríguez-Fernández et al, 2019 ).…”