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

Abstract

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 3 , with the maximum being 5.8 μg/m 3. The concentrations of EC were highest for booths that operated exclusively for trucks. The average PN concentration inside the booth was 3.54 × 10 4 cm-3 , approximately 5-fold higher than the reference indoor background. The average BC concentration in the booths were approximately 8 μg/m 3 , and the instantaneous peak concentration was 271 μg/m 3. 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.

Occupational exposure to respirable crystalline silica in municipal household waste collection and road cleaning workers

“…Of the limited research, a previous study showed that the RCS concentration of highway toll booth workers were below the detection limit 27 . Meanwhile, the GM RCS concentrations of workers who cultivated citrus and table grapes in farms in California, USA were as high as 0.08 and 0.02 mg m –3 , respectively.…”

Black Carbon Exposure Characteristics in Diesel Engine Vehicle-related Jobs

“…Several studies have reported an increased occupational exposure to BC in a large group of workers including municipal household garbage collectors (Lee et al, 2015), traffic police (Shakya et al, 2016), underground tunnel construction workers (Galea et al, 2016), farmers (Stapleton et al, 2018;Sauvé et al, 2020), subway workers (Choi et al, 2019) and toll operators (Shin et al, 2021). According to these studies, BC exposure levels were high when working with dieselpowered equipment indoors such as underground tunnels or subway.…”

“…S1(d)). A study done by Shin et al (2021) comparing the BC concentration at the same time inside and outside the tollbooth, showed that the GM concentration of BC inside booth (7.3 µg m -3 ) was 88% of the outside concentration (8.3 µg m -3 ).…”