Characterization and Quantification of Ultrafine Particles and Carbonaceous Components from Occupational Exposures to Diesel Particulate Matter in Selected Workplaces

2020 ◽  
Vol 64 (5) ◽  
pp. 490-502 ◽  
Author(s):  
Alan da Silveira Fleck ◽  
Cyril Catto ◽  
Gilles L’Espérance ◽  
Jean-Philippe Masse ◽  
Brigitte Roberge ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Size Distribution ◽  
Ultrafine Particles ◽  
Occupational Exposures ◽  
Total Carbon ◽  
Geometric Standard Deviation ◽  
Diesel Particulate Matter ◽  
Subway Tunnel ◽  
Diesel Particulate ◽  
Exposure Levels

Abstract Questions still exist regarding which indicator better estimates worker’s exposure to diesel particulate matter (DPM) and, especially for ultrafine particles (UFP), how exposure levels and the characteristics of the particles vary in workplaces with different exposure conditions. This study aimed to quantify and characterize DPM exposures in three workplaces with different exposure levels: an underground mine, a subway tunnel, and a truck repair workshop. The same sampling strategy was used and included measurements of the particle number concentration (PNC), mass concentration, size distribution, transmission electron microscopy (TEM), and the characterization of carbonaceous fractions. The highest geometric means (GMs) of PNC and elemental carbon (EC) were measured in the mine [134 000 (geometric standard deviation, GSD = 1.5) particles cm−3 and 125 (GSD = 2.1) µg m−3], followed by the tunnel [32 800 (GSD = 1.7) particles cm−3 and 24.7 (GSD = 2.4) µg m−3], and the truck workshop [22 700 (GSD = 1.3) particles cm−3 and 2.7 (GSD = 2.4) µg m−3]. This gradient of exposure was also observed for total carbon (TC) and particulate matter. The TC/EC ratio was 1.4 in the mine, 2.5 in the tunnel and 8.7 in the workshop, indicating important organic carbon interference in the non-mining workplaces. EC and PNC were strongly correlated in the tunnel (r = 0.85; P < 0.01) and the workshop (r = 0.91; P < 0.001), but a moderate correlation was observed in the mine (r = 0.57; P < 0.05). Results from TEM showed individual carbon spheres between 10 and 56.5 nm organized in agglomerates, while results from the size distribution profiles showed bimodal distributions with a larger accumulation mode in the mine (93 nm) compared with the tunnel (39 nm) and the truck workshop (34 nm). In conclusion, the composition of the carbonaceous fraction varies according to the workplace, and can interfere with DPM estimation when TC is used as indicator. Also, the dominance of particles <100 nm in all workplaces, the high levels of PNC measured and the good correlation with EC suggest that UFP exposures should receive more attention on occupational routine measurements and regulations.

Effect of lubricant oil additive on size distribution, morphology, and nanostructure of diesel particulate matter

2014 ◽  
Vol 130 ◽  
pp. 33-40 ◽  
Author(s):  
Yuesen Wang ◽  
Xingyu Liang ◽  
Gequn Shu ◽  
Xiangxiang Wang ◽  
Xiuxiu Sun ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Size Distribution ◽  
Diesel Particulate Matter ◽  
Diesel Particulate ◽  
Lubricant Oil

scholarly journals Occupational Respirable Mine Dust and Diesel Particulate Matter Hazard Assessment in an Underground Gold Mine in Ghana

2020 ◽  
Vol 10 (25) ◽  
pp. 200305
Author(s):  
Martin K. Mensah ◽  
Kwadwo Mensah-Darkwa ◽  
Carsten Drebenstedt ◽  
Bright V. Annam ◽  
Edward K. Armah
Keyword(s):  
Particulate Matter ◽  
Occupational Exposures ◽  
Crystalline Silica ◽  
Mine Safety ◽  
Dust Exposure ◽  
Diesel Particulate Matter ◽  
Gold Mine ◽  
Diesel Particulate ◽  
Silica Dust ◽  
Safety And Health

Background. Underground miners can experience occupational health diseases due to exposure to particulate matter hazards. Objectives. The aim of the present study was to examine occupational exposures of underground miners to dust and diesel particulate matter and to identify exposure groups with high potential to develop associated health effects due to the presence of dust and diesel particulate matter (DPM) hazards in an underground gold mine in Ghana. Methods. Purposive sampling was employed using gravimetric air samplers over an 8-hour time weighted average period. The National Institute for Occupational Safety and Health (NIOSH) analytical Chapter Q and 5040 were used in determining crystalline silica dust and diesel particulate matter fractions, respectively. Structured questionnaires were administered to gather data on workers' level of awareness to dust and DPM exposures. Results. It was found that 41% of the sampled groups were exposed to higher crystalline silica levels above the (NIOSH) permissible exposure limit (PEL) level of 0.05 mg/m3. For DPM, 49% of these groups had exposures above the Mine Safety and Health Administration (MSHA) PEL level of 160 μg/m3. Among the 94 mine workers who responded to this study, 62% were found to be aware of the presence and hazardous nature of silica dust, 28% had minimal knowledge and the remaining were found to be unaware. Conclusions. There are varying levels of dust and DPM due to the presence of silica-bearing rocks, the production of diesel fumes and inefficiencies of available mitigation measures. Research carried out over the past decades has found confirmed cases of silicosis and lung cancer due to high dust exposure levels. Rock drillers, blast men and shotcrete operators were found to be exposed to higher levels of dust and diesel particulate matter and are at greater risk of silicosis. Participant Consent. Obtained Ethics Approval. This study was approved by the Ethics Committee of the Kwame Nkrumah University of Science and Technology, Ghana and carried out under full consent of the mining company under study. Competing Interests. The authors declare no competing financial interests.

scholarly journals Trends in Exposure to Diesel Particulate Matter and Prevalence of Respiratory Symptoms in Western Australian Miners

2020 ◽  
Vol 17 (22) ◽  
pp. 8435
Author(s):  
Krassi Rumchev ◽  
Dong Van Hoang ◽  
Andy Lee
Keyword(s):  
Particulate Matter ◽  
Respiratory Symptoms ◽  
Elemental Carbon ◽  
Combustion Process ◽  
Mining Industry ◽  
Secondary Data ◽  
Diesel Particulate Matter ◽  
Diesel Particulate ◽  
Exposure Levels ◽  
Western Australian

Diesel-powered equipment is used frequently in the mining industry. They are energetically more efficient and emit lower quantities of carbon monoxide and carbon dioxide than the gasoline equipment. However, diesel engines release more diesel particulate matter (DPM) during the combustion process which has been linked to harmful health effects. This study assessed the trends in DPM exposure and the prevalence of respiratory symptoms among Western Australian miners, using the available secondary data collected from 2006 to 2012. The data consisted of elemental carbon (EC) concentrations and information on miner’s respiratory symptoms. The measured EC concentrations from n = 2598 miners ranged between 0.01 mg/m3 and 1.00 mg/m3 and tended to significantly decrease over the study period (p < 0.001). Underground mine workers were exposed to significantly higher (p < 0.01) median EC concentrations of 0.069 mg/m3 (IQR 0.076) when compared to surface workers’ 0.038 mg/m3 (IQR 0.04). Overall, 29% of the miners reported at least one respiratory symptom, with the highest frequency recorded for cough (16%). Although the exposure levels of DPM in the mining industry of Western Australia have declined over the study period, they are still high and adhering to stringent occupational standard for DPM is recommended.

Effects of CVS Tunnel, Ambient and Instrument Dilution on Characteristics of Nano Diesel Particulate Matter Evolution

2012 ◽  
Author(s):  
Yuebin Wu ◽  
Nigel N. Clark ◽  
Daniel K. Carder
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Diesel Engine ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Diesel Particulate Matter ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Diesel Particulate ◽  
Exhaust Plume

In 2007, U.S. certification standards for heavy duty on-road diesel engine particulate matter (PM) emissions were reduced from 0.1g/bhp-hr to 0.01g/bhp-hr, representing an order of magnitude reduction in pollutant level. The Tier 4 standards for nonroad diesel engines, being phased in from 2008 through 2015, also require similar level of reduction in PM. Most conventional diesel engines could meet these low PM standards, once equipped with a diesel particulate filter (DPF). However, accurate, repeatable measurements of this PM may pose significant challenges. Gravimetric PM measurement involves diluting exhaust, then collecting the resultant aerosol sample on approved filter media. Few data exist to characterize the evolution of particulate matter (PM) in dilution tunnels, particularly at very low PM mass levels. Data are lacking as well, for PM evolution in portable dilution instruments and in exhaust plumes downstream of the tailpipe. Size distributions of ultra-fine particles in the diesel exhaust from a naturally aspirated ISUZU C240 diesel engine, equipped with a DPF, were studied. Particle size distribution data, during steady-state engine operations, were collected using a Cambustion DMS500 Fast Particulate Spectrometer. The effects of dilution ratios, dilution rates, and residence times on the diesel particulate matter (DPM) size distributions were analyzed and discussed. Measurements were made for three dilution methods: dilution in standard primary and secondary-dilution tunnels with a full scale Constant Volume Sampler (CVS) system, instrument dilution with a Portable Particulate Measurement Device (PPMD), and ambient dilution at the post-tailpipe exhaust plume centerline. Gaseous emissions measurements were utilized as surrogate confirmation of adequate mixing at the various measurement locations, as well as an indicator of dilution ratios. Tunnel sample results indicated varying size distributions at tunnel cross sections where the flow was still developing. Evolution of particle-size distributions was observed even for fully mixed primary flow conditions. Size distributions at the end of the secondary dilution tunnel were observed to vary with different secondary-dilution ratios. Particle-size distributions of post-tailpipe and PPMD test results were analyzed and compared with those results collected from the full-flow tunnel. Results from post-tailpipe sampling indicate that nucleation was the dominant process when the exhaust plume was diluted along the post-tailpipe centerline. Results from PPMD dilution measurements indicate that change of particle-size-distribution curves, including number count and mass concentration levels, were not as strongly correlated to dilution ratios as were the results from the other two sampling methods. This study shows that particle-size distributions measured inside full-flow dilution tunnel can adequately mimic freshly emitted exhaust sampled immediately post-tailpipe.

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