Exposure assessment of workplace manufacturing titanium dioxide particles

Abstract

With the widespread use of titanium dioxide (TiO₂) human exposure is inevitable, but the exposure data on TiO₂ are still limited. This study adopted off-line filter-based sampling combined with real-time activity-based monitoring to measure the concentrations in a workplace manufacturing TiO₂ (primary diameter: 194 ± 108 nm). Mass concentrations (MCs) of aerosol particles in the packaging workshop (total dust: 3.17 mg/m³, nano dust: 1.22 mg/m³) were much higher than those in the milling workshop (total dust: 0.79 mg/m³, nano dust: 0.31 mg/m³) and executive office (total dust: 0.44 mg/m³, nano dust: 0.19 mg/m³). However, the MCs of TiO₂ were at a relatively low level in the packaging workshop (total TiO₂: 46.4 μg/m³, nano TiO₂: 16.7 μg/m³) and milling workshop (total TiO₂: 39.4 μg/m³, nano TiO₂: 19.4 μg/m³) by ICP-MS. The number concentration (NC), surface area concentration (SAC) of aerosol particles potentially deposited in alveolar (SAC_A), and tracheobronchial (SAC_TB) regions of lungs in the packaging workshop were (1.04 ± 0.89) × 10⁵ particles/cm³, 414.49 ± 395.07, and 86.01 ± 83.18 μm²/cm³, respectively, which were all significantly higher than those of the milling workshop [(0.12 ± 0.40) × 10⁵ particles/cm³, 75.38 ± 45.23, and 17.60 ± 9.22 μm²/cm³, respectively] as well as executive office and outdoor background (p < 0.05). Activity-related characteristics were found in both workshops, and the time-variant characteristics showed very similar trends for 3 days in the packaging workshop. Our study provides important data of TiO₂ particles exposure in the workplace.

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