Task-Specific Noise Exposure During Manual Concrete Surface Grinding in Enclosed Areas-Influence of Operation Variables and Dust Control Methods

• Published in: Journal of occupational and environmental hygiene Vol. 10; no. 9; pp. 478 - 486
• Main Authors: Akbar-Khanzadeh, Farhang, Ames, April L., Milz, Sheryl A., Akbar-Khanzadeh, Mahboubeh
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 2013; Taylor & Francis; Taylor & Francis LLC
• Subjects: Air Pollutants, Occupational - analysis; Biological and medical sciences; Concrete; concrete grinding; Construction Materials; Dust; Dust - analysis; enclosed areas; Environmental Monitoring - methods; Grinding; hand-held grinder; Hearing protection; Medical sciences; noise exposure; Noise pollution; Noise, Occupational; Occupational Exposure - analysis; Occupational Exposure - prevention & control; Occupational medicine; Protective Devices; Public health. Hygiene-occupational medicine; Studies; Ventilation; Human; Noise; enclosed areas; Manuals; Grinding(comminution); Operation; Occupational exposure; Grinding; Dust; Grinding down; concrete grinding; hand-held grinder; Concrete; Control method; noise exposure; Occupational medicine
• ISSN: 1545-9624; 1545-9632
• DOI: 10.1080/15459624.2013.818230

Noise exposure is a distinct hazard during hand-held concrete grinding activities, and its assessment is challenging because of the many variables involved. Noise dosimeters were used to examine the extent of personal noise exposure while concrete grinding was performed with a variety of grinder sizes, types, accessories, and available dust control methods. Noise monitoring was conducted in an enclosed area covering 52 task-specific grinding sessions lasting from 6 to 72 minutes. Noise levels, either in minute average noise level (Lavg, dBA) or in minute peak (dBC), during concrete grinding were significantly (P < 0.01) correlated with general ventilation (GV: on, off), dust control methods (uncontrolled, wet, Shop-Vac, HEPA, HEPA-Cyclone), grinding cup wheel (blade) sizes of 4-inch (100 mm), 5-inch (125 mm) and 6-inch (150 mm), and surface orientation (horizontal, inclined). Overall, minute Lavg during grinding was 97.0 ± 3.3 (mean ± SD), ranging from 87.9 to 113. The levels of minute Lavg during uncontrolled grinding (98.9 ± 5.2) or wet-grinding (98.5 ± 2.7) were significantly higher than those during local exhaust ventilation (LEV) grinding (96.2 ± 2.8). A 6-inch grinding cup wheel generated significantly higher noise levels (98.7 ± 2.8) than 5-inch (96.3 ± 3.2) or 4-inch (95.3 ± 3.5) cup wheels. The minute peak noise levels (dBC) during grinding was 113 ± 5.2 ranging from 104 to 153. The minute peak noise levels during uncontrolled grinding (119 ± 10.2) were significantly higher than those during wet-grinding (115 ± 4.5) and LEV-grinding (112 ± 3.4). A 6-inch grinding cup wheel generated significantly higher minute peak noise levels (115 ± 5.3) than 5-inch (112 ± 4.5) or 4-inch (111 ± 5.4) cup wheels. Assuming an 8-hour work shift, the results indicated that noise exposure levels during concrete grinding in enclosed areas exceeded the recommended permissible exposure limits and workers should be protected by engineering control methods, safe work practices, and/or personal protective devices.