scholarly journals Exposure to Ultrafine Particles in the Ferroalloy Industry Using a Logbook Method

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2546
Author(s):  
Rikke Bramming Jørgensen ◽  
Ida Teresia Kero ◽  
Aleksander Blom ◽  
Esten Eide Grove ◽  
Kristin von Hirsch Svendsen
Keyword(s):  
Exposure Assessment ◽  
Ultrafine Particles ◽  
Weighted Average ◽  
Average Concentration ◽  
Respirable Particles ◽  
Exposure Estimation ◽  
Close Proximity ◽  
Personal Sampling ◽  
Time Weighted Average ◽  
Stationary Sampling

Background: It is difficult to assess workers’ exposure to ultrafine particles (UFP) due to the lack of personal sampling equipment available for this particle fraction. The logbook method has been proposed as a general method for exposure assessment. This method measures the time and concentration components of the time-weighted average concentration separately and could be suitable for investigation of UFP exposure. Objectives: In this study, we have assessed workers’ exposure to UFP in a ferrosilicon plant. The main tasks of the furnace workers were identified, and the logbook method was used in combination with stationary measurements of UFP taken as close to the identified task areas as possible. In order to verify the results, respirable particles were collected using stationary sampling in close proximity to the UFP measuring instrument, and personal full-shift sampling of respirable particles was performed simultaneously. Thus, exposure to respirable particles determined using the logbook method could be compared to the results of standard measurement. Methods: The particle number concentration of ultrafine particles was determined using a NanoScan SMPS. Respirable particle concentration and exposure were determined using a sampling train consisting of a pump, filter, filter cassettes, and SKC Cyclone for the respirable fraction. Attendance times for workers at each work location were registered via thorough observations made by the research team. Results: The logbook method for exposure estimation based on stationary sampling equipment made it possible to calculate UFP exposure for workers operating the furnaces at a ferrosilicon plant. The mid-size furnace and the large furnace were evaluated separately. The workers operating the largest furnace were exposed to 1.47 × 104 particles/cm3, while workers operating the mid-size furnace were exposed to 2.06 × 104 particles/cm3, with a mean of 1.74 × 104 particles/cm3. Substantial contributions from the casting area, ladle transport corridor, and both tapping areas were made. Exposure to respirable particles was 2.04 mg/m3 (logbook); 2.26 mg/m3 (personal sampling) for workers operating the large-sized furnace, 3.24 mg/m3 (logbook); 2.44 mg/m3 (personal sampling) for workers operating the medium-sized furnace, and 2.57 mg/m3 (logbook); 2.53 mg/m3(personal sampling) on average of all tappers. The average ratio of these two methods’ results was 1.02, which indicates that the logbook method could be used as a substitute for personal sampling when it is not possible to perform personal sampling, at least within this industry. Conclusions: The logbook method is a useful supplement for exposure assessment of UFP, able to identify the most polluted areas of the workplace and the contribution of different work tasks to the total exposure of workers, enabling companies to take action to reduce exposure.

scholarly journals Exposure assessment of elemental carbon, ultrafine particles, and crystalline silica at highway toll booths

2020 ◽  
Vol 26 (5) ◽  
pp. 200380-0
Author(s):  
Jungah Shin ◽  
Boowook Kim ◽  
Jeonghoon Lee ◽  
Joon Sig Jung ◽  
Yong Chul Shin ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Ultrafine Particles ◽  
Elemental Carbon ◽  
Particle Number ◽  
Ultrafine Particle ◽  
Average Concentration ◽  
Crystalline Silica ◽  
Respiratory Protection ◽  
Increased Risk ◽  
Occupational Lung Cancer

Highway toll booth workers have been reported to be at an increased risk of occupational lung cancer. Moreover, insufficient studies have been performed on exposure assessment of workers at highway toll booths. Elemental carbon (EC), black carbon (BC), and respirable crystalline silica (RCS) concentrations were measured at highway toll booths in Gyeongsangbuk-do (Republic of Korea). The particle number (PN) concentration and size distribution of ultrafine particle were measured using three SMPS devices. The average concentration of the EC inside the booth was 3.3 μg/m<sup>3</sup>, with the maximum being 5.8 μg/m<sup>3</sup>. The concentrations of EC were highest for booths that operated exclusively for trucks. The average PN concentration inside the booth was 3.54 × 10<sup>4</sup> cm<sup>-3</sup>, approximately 5-fold higher than the reference indoor background. The average BC concentration in the booths were approximately 8 μg/m<sup>3</sup>, and the instantaneous peak concentration was 271 μg/m<sup>3</sup>. The RCS was below the detection limit in all samples. This study revealed that toll workers were most frequently exposed to diesel engine particle less than 100 nm, with an extremely high respiratory deposition rate. Therefore, a respiratory protection program is necessary to safeguard these workers against vehicle-related pollutants.

Prediction of human sensory irritation due to ethyl acrylate: the appropriateness of time-weighted average concentration × time models for varying concentrations

2017 ◽  
Vol 91 (9) ◽  
pp. 3051-3064 ◽  
Author(s):  
Stefan Kleinbeck ◽  
Michael Schäper ◽  
Anna Zimmermann ◽  
Meinolf Blaszkewicz ◽  
Thomas Brüning ◽  
...  
Keyword(s):  
Weighted Average ◽  
Ethyl Acrylate ◽  
Average Concentration ◽  
Sensory Irritation ◽  
Concentration Time ◽  
Time Weighted Average

scholarly journals STUDI FAAL PARU DAN FAKTOR DETERMINANNYA PADA PEKERJA DI INDUSTRI SAWMILL

2019 ◽  
Vol 7 (3) ◽  
pp. 357
Author(s):  
Ulfa Hikmayanti
Keyword(s):  
Body Mass Index ◽  
Lung Function ◽  
Body Mass ◽  
Weighted Average ◽  
Average Concentration ◽  
Wood Dust ◽  
Protective Equipment ◽  
Impaired Lung Function ◽  
Time Weighted Average ◽  
Sawmill Industry

Sawmill industry processes log into sawmill and also results wood dust as by-product . Dust can be potentially inhaled by workers and cause impaired lung function. In addition, several other factors can effect lung function such as age, body mass index status, smoking habit and using respiratory protective equipment habits. The purpose of this study was to describe lung function on workers in sawmill industry and the determinant factors. This research was an observational type with descriptive method. This study used total population with 36 workers. The data were obtained from interview, dust measurement, body mass index measurement and lung function test, meanwhile the instruments were questionnaire, high volume dust sampler (hvds), microtoise, weight scale and spirometer. This data were analyzed by cross tabulation. The results of this study showed that the time weighted average concentration in UD. Sinar Abadi was 1.59 mg/m3, meanwhile spirometry test showed 42.8% had normal lung function and 52.8% had impaired lung function. Workers who had impaired lung function were 64.7% exposed to doses >5mg/m3.tahun, 60% were >44 years old, 100% were obese, 69.9% were smoker and 76.5% never used respiratory protective equipment. The time weighted average concentration was above from threshold limit value and most of the workers had impaired lung function. Workers with impaired lung function are more likely to be exposed to dose >5mg/m3.years, older, obese, smoker, and didn’t use respiratory protective equipment. Keywords: determinant factors, lung function, wood dust

scholarly journals The Effect of Route Choice in Children’s Exposure to Ultrafine Particles Whilst Walking to School

2021 ◽  
Vol 18 (15) ◽  
pp. 7808
Author(s):  
Mehrdad Rafiepourgatabi ◽  
Alistair Woodward ◽  
Jennifer A. Salmond ◽  
Kim Natasha Dirks
Keyword(s):  
Ultrafine Particles ◽  
Route Choice ◽  
The Other ◽  
Close Proximity ◽  
Public Health Officials ◽  
Risk Of Exposure ◽  
The Mean ◽  
Walking To School ◽  
Elevated Exposure ◽  
Children’S Exposure

Children walking to school are at a high risk of exposure to air pollution compared with other modes because of the time they spend in close proximity to traffic during their commute. The aim of this study is to investigate the effect of a walker’s route choice on their exposure to ultrafine particles (UFP) on the walk to school. During morning commutes over a period of three weeks, exposure to UFP was measured along three routes: two routes were alongside both sides of a busy arterial road with significantly higher levels of traffic on one side compared to the other, and the third route passed through quiet streets (the background route). The results indicate that the mean exposure for the pedestrian walking along the background route was half the exposure experienced on the other two routes. Walkers on the trafficked side were exposed to elevated concentrations (>100,000 pt/cc) 2.5 times longer than the low-trafficked side. However, the duration of the elevated exposure for the background route was close to zero. Public health officials and urban planners may use the results of this study to promote healthier walking routes to schools, especially those planned as part of organized commutes.

scholarly journals Treatment of thoracolumbar burst fractures: extended follow-up of a randomized clinical trial comparing orthosis versus no orthosis

2017 ◽  
Vol 27 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Jennifer C. Urquhart ◽  
Osama A. Alrehaili ◽  
Charles G. Fisher ◽  
Alyssa Fleming ◽  
Parham Rasoulinejad ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Weighted Average ◽  
Average Treatment Effect ◽  
Secondary Outcome ◽  
Thoracolumbar Burst Fractures ◽  
Treatment Comparison ◽  
Average Treatment ◽  
Burst Fractures ◽  
Time Weighted Average

OBJECTIVEA multicenter, prospective, randomized equivalence trial comparing a thoracolumbosacral orthosis (TLSO) to no orthosis (NO) in the treatment of acute AO Type A3 thoracolumbar burst fractures was recently conducted and demonstrated that the two treatments following an otherwise similar management protocol are equivalent at 3 months postinjury. The purpose of the present study was to determine whether there was a difference in long-term clinical and radiographic outcomes between the patients treated with and those treated without a TLSO. Here, the authors present the 5- to 10-year outcomes (mean follow-up 7.9 ± 1.1 years) of the patients at a single site from the original multicenter trial.METHODSBetween July 2002 and January 2009, a total of 96 subjects were enrolled in the primary trial and randomized to two groups: TLSO or NO. Subjects were enrolled if they had an AO Type A3 burst fracture between T-10 and L-3 within the previous 72 hours, kyphotic deformity < 35°, no neurological deficit, and an age of 16–60 years old. The present study represents a subset of those patients: 16 in the TLSO group and 20 in the NO group. The primary outcome measure was the Roland Morris Disability Questionnaire (RMDQ) score at the last 5- to 10-year follow-up. Secondary outcome measures included kyphosis, satisfaction, the Numeric Rating Scale for back pain, and the 12-Item Short-Form Health Survey (SF-12) Mental and Physical Component Summary (MCS and PCS) scores. In the original study, outcome measures were administered at admission and 2 and 6 weeks, 3 and 6 months, and 1 and 2 years after injury; in the present extended follow-up study, the outcome measures were administered 5–10 years postinjury. Treatment comparison between patients in the TLSO group and those in the NO group was performed at the latest available follow-up, and the time-weighted average treatment effect was determined using a mixed-effects model of longitudinal regression for repeated measures averaged over all time periods. Missing data were assumed to be missing at random and were replaced with a set of plausible values derived using a multiple imputation procedure.RESULTSThe RMDQ score at 5–10 years postinjury was 3.6 ± 0.9 (mean ± SE) for the TLSO group and 4.8 ± 1.5 for the NO group (p = 0.486, 95% CI −2.3 to 4.8). Average kyphosis was 18.3° ± 2.2° for the TLSO group and 18.6° ± 3.8° for the NO group (p = 0.934, 95% CI −7.8 to 8.5). No differences were found between the NO and TLSO groups with time-weighted average treatment effects for RMDQ 1.9 (95% CI −1.5 to 5.2), for PCS −2.5 (95% CI −7.9 to 3.0), for MCS −1.2 (95% CI −6.7 to 4.2) and for average pain 0.9 (95% CI −0.5 to 2.2).CONCLUSIONSCompared with patients treated with a TLSO, patients treated using early mobilization without orthosis maintain similar pain relief and improvement in function for 5–10 years.

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