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Evaluation of cut-off saw exposure control methods for respirable dust and crystalline silica in roadway construction.
J Occup Environ Hyg. 2012; 9(3):157-65.JO

Abstract

Dust reduction equipment adapted for single-person operation was evaluated for gas-powered, commercially available cut-off saws during concrete curb cutting. Cutting was performed without dust control and with two individual exposure control methods: wet suppression and local exhaust ventilation (LEV). The wet suppression system comprised a two-nozzle spray system and a 13.3-L hand-pressurized water supply system with an optimum mean flow rate of 0.83 L/min for 16 min of cutting. The LEV system consisted of a spring-loaded guard, an 18.9-L collection bag, and a centrifugal fan with an estimated exhaust rate of 91 ft(3)/min. Task-based, personal filter samples were obtained for four saw operators during cutting durations of 4 to 16 min on five job sites. Seventeen filter samples were collected without dust control, 14 with wet suppression, and 12 with LEV, yielding a geometric mean respirable dust concentration of 16.4 mg/m(3), 3.60 mg/m(3), and 4.40 mg/m(3), respectively. A dust reduction of 78.0% for wet suppression and 73.2% for LEV was observed vs. no dust control. A statistically significant difference (p < 0.001) was also revealed for wet suppression and LEV when compared with no dust control; however, a significant difference (p = 0.09) was not observed between wet suppression and LEV. Despite these significant dust reductions, workers are still projected to exceed the ACGIH 8-hr time-weighted average threshold limit value for quartz (0.025 mg/m(3)) in less than 1 hr of cutting for both dust control methods. Further research is still needed to improve dust reduction and portability of both control methods, but the current LEV system offers important advantages, including a drier, less slippery work area and year-round functionality in cold weather.

Authors+Show Affiliations

School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, USA. bmiddaug@purdue.eduNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Evaluation Study
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22394370

Citation

Middaugh, Beauregard, et al. "Evaluation of Cut-off Saw Exposure Control Methods for Respirable Dust and Crystalline Silica in Roadway Construction." Journal of Occupational and Environmental Hygiene, vol. 9, no. 3, 2012, pp. 157-65.
Middaugh B, Hubbard B, Zimmerman N, et al. Evaluation of cut-off saw exposure control methods for respirable dust and crystalline silica in roadway construction. J Occup Environ Hyg. 2012;9(3):157-65.
Middaugh, B., Hubbard, B., Zimmerman, N., & McGlothlin, J. (2012). Evaluation of cut-off saw exposure control methods for respirable dust and crystalline silica in roadway construction. Journal of Occupational and Environmental Hygiene, 9(3), 157-65. https://doi.org/10.1080/15459624.2012.658265
Middaugh B, et al. Evaluation of Cut-off Saw Exposure Control Methods for Respirable Dust and Crystalline Silica in Roadway Construction. J Occup Environ Hyg. 2012;9(3):157-65. PubMed PMID: 22394370.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Evaluation of cut-off saw exposure control methods for respirable dust and crystalline silica in roadway construction. AU - Middaugh,Beauregard, AU - Hubbard,Bryan, AU - Zimmerman,Neil, AU - McGlothlin,James, PY - 2012/3/8/entrez PY - 2012/3/8/pubmed PY - 2012/7/19/medline SP - 157 EP - 65 JF - Journal of occupational and environmental hygiene JO - J Occup Environ Hyg VL - 9 IS - 3 N2 - Dust reduction equipment adapted for single-person operation was evaluated for gas-powered, commercially available cut-off saws during concrete curb cutting. Cutting was performed without dust control and with two individual exposure control methods: wet suppression and local exhaust ventilation (LEV). The wet suppression system comprised a two-nozzle spray system and a 13.3-L hand-pressurized water supply system with an optimum mean flow rate of 0.83 L/min for 16 min of cutting. The LEV system consisted of a spring-loaded guard, an 18.9-L collection bag, and a centrifugal fan with an estimated exhaust rate of 91 ft(3)/min. Task-based, personal filter samples were obtained for four saw operators during cutting durations of 4 to 16 min on five job sites. Seventeen filter samples were collected without dust control, 14 with wet suppression, and 12 with LEV, yielding a geometric mean respirable dust concentration of 16.4 mg/m(3), 3.60 mg/m(3), and 4.40 mg/m(3), respectively. A dust reduction of 78.0% for wet suppression and 73.2% for LEV was observed vs. no dust control. A statistically significant difference (p < 0.001) was also revealed for wet suppression and LEV when compared with no dust control; however, a significant difference (p = 0.09) was not observed between wet suppression and LEV. Despite these significant dust reductions, workers are still projected to exceed the ACGIH 8-hr time-weighted average threshold limit value for quartz (0.025 mg/m(3)) in less than 1 hr of cutting for both dust control methods. Further research is still needed to improve dust reduction and portability of both control methods, but the current LEV system offers important advantages, including a drier, less slippery work area and year-round functionality in cold weather. SN - 1545-9632 UR - https://www.unboundmedicine.com/medline/citation/22394370/Evaluation_of_cut_off_saw_exposure_control_methods_for_respirable_dust_and_crystalline_silica_in_roadway_construction_ L2 - https://www.tandfonline.com/doi/full/10.1080/15459624.2012.658265 DB - PRIME DP - Unbound Medicine ER -