Finnish Institute of Occupational Health, Nanosafety Research Centre, Helsinki, Finland.
Inhal Toxicol. 2012 Oct;24(12):839-49. doi: 10.3109/08958378.2012.724474.
Titanium dioxide (TiO₂) factory workers' source specific exposure and dose to airborne particles was studied extensively for particles between 5 nm and 10 μm in size.
We defined TiO₂ industry workers' quantitative inhalation exposure levels during the packing of pigment TiO₂ (pTiO₂) and nanoscale TiO₂ (nTiO₂) material from concentrations measured at work area.
Particle emissions from different work events were identified by linking work activity with the measured number size distributions and mass concentrations of particles. A lung deposit model was used to calculate regional inhalation dose rates in units of particles min⁻¹ and μg min⁻¹ without use of respirators.
Workers' average exposure varied from 225 to 700 μg m⁻³ and from 1.15 × 10⁴ to 20.1 × 10⁴ cm⁻⁴. Over 90% of the particles were smaller than 100 nm. These were mainly soot and particles formed from process chemicals. Mass concentration originated primarily from the packing of pTiO₂ and nTiO₂ agglomerates. The nTiO₂ exposure resulted in a calculated dose rate of 3.6 × 10⁶ min⁻¹ and 32 μg min⁻¹ where 70% of the particles and 85% of the mass was deposited in head airways.
The recommended TiO₂ exposure limits in mass by NIOSH and in particle number by IFA were not exceeded. We recommend source-specific exposure assessment in order to evaluate the workers' risks. In nTiO₂ packing, mass concentration best describes the workers' exposure to nTiO₂ agglomerates. Minute dose rates enable the simulation of workers' risks in different exposure scenarios.
人们对 5nm 至 10μm 大小的空气传播颗粒物进行了广泛研究，以了解二氧化钛（TiO₂）工厂工人的特定来源暴露和剂量。
我们根据工作区域测量的浓度，定义了包装颜料二氧化钛（pTiO₂）和纳米二氧化钛（nTiO₂）材料时 TiO₂ 行业工人的定量吸入暴露水平。
通过将工作活动与测量的粒径分布和颗粒物质量浓度相关联，确定了不同工作事件产生的颗粒物排放。使用肺部沉积模型计算无使用呼吸防护器时单位为颗粒 min⁻¹ 和μg min⁻¹ 的区域吸入剂量率。
工人的平均暴露量从 225μg/m³到 700μg/m³不等，从 1.15×10⁴cm⁻⁴到 20.1×10⁴cm⁻⁴不等。超过 90%的颗粒物小于 100nm。这些主要是烟尘和来自工艺化学品的颗粒。质量浓度主要来源于 pTiO₂和 nTiO₂团聚体的包装。nTiO₂ 暴露导致计算出的剂量率为 3.6×10⁶min⁻¹和 32μg min⁻¹，其中 70%的颗粒和 85%的质量沉积在头气道中。
NIOSH 规定的质量 TiO₂ 暴露限值和 IFA 规定的颗粒数 TiO₂ 暴露限值均未超标。我们建议进行特定源暴露评估，以评估工人的风险。在 nTiO₂ 包装中，质量浓度最好地描述了工人接触 nTiO₂ 团聚体的情况。剂量率可模拟不同暴露场景下工人的风险。
