Calcium carbonate nanomaterials (nano-CaCO₃) are widely used in both manufacturing and consumer products, but their potential health hazards remain unclear. The objective of this study was to survey workplace exposure levels and health effects of workers exposed to nano-CaCO₃. Personal and area sampling, as well as real-time and dust monitoring, were performed to characterize mass exposure, particle size distribution, and particle number exposure. A total of 56 workers (28 exposed workers and 28 unexposed controls) were studied in a cross-sectional study. They completed physical examinations, spirometry, and digital radiography. The results showed that the gravimetric nano-CaCO₃ concentration was 5.264 ± 6.987 mg/m³ (0.037–22.192 mg/m³) at the workplace, and 3.577 ± 2.065 mg/m³ (2.042–8.161 mg/m³) in the breathing zone of the exposed workers. The particle number concentrations ranged from 8193 to 39 621 particles/cm³ with a size range of 30–150 nm. The process of packing had the highest gravimetric and particle number concentrations. The particle number concentration positively correlated with gravimetric concentrations of nano-CaCO₃. The levels of hemoglobin, creatine phosphokinase (CK), lactate dehydrogenase, and high-density lipoprotein cholesterol (HDL-C) in the nano-CaCO₃ exposure group increased significantly, but the white blood cell count (WBC), Complement 3 (C3), total protein (TP), uric acid, and creatinine (CREA) all decreased significantly. The prevalence rate of pulmonary hypofunction was significantly higher (p = 0.037), and the levels of vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, peak expiratory flow and forced expiratory flow 25% (FEF 25%), FEF 25–75% were negatively correlated with gravimetric concentrations of nano-CaCO₃ (p < 0.05). Logistic analysis showed that nano-CaCO₃ exposure level was associated with pulmonary hypofunction (p = 0.005). Meanwhile, a dose-effect relationship was found between the accumulated gravimetric concentrations of nano-CaCO₃ and the prevalence rate of pulmonary hypofunction (p = 0.048). In conclusion, long-term and high-level nano-CaCO₃ exposure can induce pulmonary hypofunction in workers. Thus, lung function examination is suggested for occupational populations with nano-CaCO₃ exposure. Furthermore, future health protection efforts should focus on senior workers with accumulation effects of nano-CaCO₃ exposure.

中文翻译：

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碳酸钙纳米材料暴露在职业工人中引起的肺功能减退：一项横断面研究

碳酸钙纳米材料（nano-CaCO ₃）广泛用于制造和消费产品，但其潜在的健康危害尚不清楚。这项研究的目的是调查暴露于纳米CaCO _3的工作场所的暴露水平和工人的健康影响。进行了个人和区域采样以及实时和灰尘监测，以表征质量暴露，粒度分布和颗粒数量暴露。在横断面研究中，总共研究了56名工人（28名裸露的工人和28名未暴露的对照）。他们完成了体格检查，肺活量测定和数字射线照相。结果表明，纳米CaCO ₃的重量浓度为5.264±6.987 mg / m ^3。（0.037–22.192 mg / m ³）在工作场所，暴露工人的呼吸区域为3.577±2.065 mg / m ³（2.042–8.161 mg / m ³）。颗粒数浓度范围为8193至39 621颗粒/ cm ³，尺寸范围为30-150 nm。包装过程的重量和颗粒数浓度最高。颗粒数浓度与纳米CaCO _3的重量浓度呈正相关。纳米CaCO _3中的血红蛋白，肌酸磷酸激酶（CK），乳酸脱氢酶和高密度脂蛋白胆固醇（HDL-C）的水平暴露组明显增加，但白细胞计数（WBC），补体3（C3），总蛋白（TP），尿酸和肌酐（CREA）均显着下降。肺功能低下的患病率显着更高（p  = 0.037），并且肺活量（VC），强制肺活量（FVC），一秒钟强迫呼气量（FEV1），FEV1 / FVC，呼气峰值流量和强制呼气流量25％（FEF 25％），FEF 25–75％与纳米CaCO _3的重量浓度呈负相关（p  <0.05）。Logistic分析表明，纳米CaCO ₃暴露水平与肺功能低下有关（p = 0.005）。同时，发现累积的纳米CaCO ₃重量浓度与肺功能低下的患病率之间存在剂量效应关系（p  = 0.048）。总之，长期和高水平的纳米CaCO ₃暴露会诱发工人的肺功能低下。因此，建议对纳米CaCO ₃暴露的职业人群进行肺功能检查。此外，未来的健康保护工作应将重点放在具有纳米CaCO ₃暴露累积效应的高级工人上。