Airborne Particulate Matter in a Ready-mix Concrete Plant and Assessment of a New Air Curtain Technology for Protecting Workers From Dust Exposures

Document Type

Presentation

Presentation Date

11-8-2022

Abstract or Description

Background and Objectives
Ready-mix concrete (RMC) workers are at increased risk of respiratory diseases. Little is known about RMC workers’ exposure to particulate matter (PM) and adequate respiratory protection. The study objectives were to investigate PM exposure levels in a large RMC plant and to assess workplace protection factors (WPF) against PM of different sizes with a new patented air curtain technology. This technology was considered because during hot working conditions the cooling air curtain can prevent heat fatigue providing double benefits for worker safety.


Methods
Concentrations of airborne PM of 0.3, 0.5, 1.0, 2.5, 5.0, and 10µm sizes near workers' (n=10) breathing zone were determined (10x6=60 measurements) during the active work hours by using a 23V750 particle counter. Same PM concentrations were simultaneously measured inside the air curtain (90 CFM) mounted in a helmet for these workers when they were wearing this helmet using a second particle counter. The WPFs were calculated, and a questionnaire survey determined workers' perceptions of the user friendliness of the helmet immediately after the tests.


Results
The concentrations of 0.3, 2.5, and 10µm particles, which are often regulated in workplaces, were 103,085±81,409/m(3), 624±512/m(3), and 54±66/m(3), respectively. Corresponding WPF>1 was observed in 32, 29, and 27 measurements, and the highest WPF observed was 3.29 for 10µm particle. ≥60% ‘strongly agree’ responses from workers were obtained for ‘easy to put on’, ‘not difficult to communicate’, ‘no breathing resistance’, ‘no excess noise, vibration, pressure, or tightness’ related questions.


Conclusions
Submicron 0.3µm particle concentrations reached up to 10(7)/m(3), whereas PM2.5 and PM10 reached up to 10(3)/m(3) and 10(2)/m(3). Mixed results on WPFs were observed for the air curtain technology, possibly due to windy conditions and lower openings in the curtain. In general, workers agreed that the air curtain technology is user-friendly during the work at RMC plant.

Additional Information

Georgia Southern University faculty members, Atin Adhikari and Aniruddha Mitra co-presented Airborne Particulate Matter in a Ready-mix Concrete Plant and Assessment of a New Air Curtain Technology for Protecting Workers From Dust Exposures in the American Public Health Association (APHA) Annual Conference, November 2022.

Sponsorship/Conference/Institution

American Public Health Association (APHA) Annual Conference

Location

Boston, MA

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