Refractory ceramic fibers (RCFs) can cause adverse health effects on workers’ respiratory system, yet no proper biomarkers have been used to detect early pulmonary injury of RCFs-exposed workers. This study assessed the levels of two biomarkers that are related to respiratory injury in RCFs-exposed workers, and explored their relations with lung function. The exposure levels of total dust and respirable fibers were measured simultaneously in RCFs factories. The levels of TGF-β1 and ceruloplasmin (CP) increased with the RCFs exposure level (p < 0.05), and significantly increased in workers with high exposure level (1.21 ± 0.49 ng/mL, 115.25 ± 32.44 U/L) when compared with the control group (0.99 ± 0.29 ng/mL, 97.90 ± 35.01 U/L) (p < 0.05). The levels of FVC and FEV1 were significantly decreased in RCFs exposure group (p < 0.05). Negative relations were found between the concentrations of CP and FVC (B = −0.423, p = 0.025), or FEV1 (B = −0.494, p = 0.014). The concentration of TGF-β1 (B = 0.103, p = 0.001) and CP (B = 8.027, p = 0.007) were associated with respirable fiber exposure level. Occupational exposure to RCFs can impair lung ventilation function and may have the potential to cause pulmonary inflammation and fibrosis. TGF-β1 and CP might be used as sensitive and noninvasive biomarkers to detect lung injury in occupational RCFs-exposed workers. Respirable fiber concentration can better reflect occupational RCFs exposure and related respiratory injuries.

Since the number of greenhouse workers are increasing in China, this observational cross-sectional study was designed to evaluate lung function and discuss the potential risk factors, to provide evidence in the surveillance of greenhouse workers’ health. 678 greenhouse workers in Gansu Province, China were enrolled. A questionnaire which included demographic and occupational information was used. Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and FEV1:FVC ratios (FEV1/FVC), maximal expiratory flow after 50% of the FVC has not been exhaled (MEF50), maximal expiratory flow after 25% of the FVC has not been exhaled (MEF25) and maximal mid-expiratory flow curve (MMEF) were measured as lung function indicators. The mean values and standard deviations (SDs) of VC% predicted, FVC% predicted, FEV1% predicted and FEV1/FVC ratio were 106.07 ± 13.36, 107.60 ± 13.95, 97.19 ± 14.80 and 89.76 ± 10.78 respectively. The positive rates of above four and abnormal lung ventilation function were 2.9%, 2.8%, 11.2%, 4.6% and 6.5% respectively. Gender, age, BMI and number of greenhouses owned were influence factors of lung ventilation function (p < 0.05). The mean values and SDs of MEF50% predicted, MEF25% predicted and MMEF% predicted were 69.63 ± 24.95, 54.04 ± 24.94 and 66.81 ± 24.53. The positive rates of above three and abnormal small airway function were 45.0%, 72.1%, 47.2% and 49.4% respectively. Age, education and number of greenhouses owned were influence factors for small airway function (p < 0.05). Working in a greenhouse might influence lung function of the workers. Small airway function indicators could be used as priority indicators for the surveillance of greenhouse workers’ health.

Refractory ceramic fibers (RCFs) are increasingly used as heating‐insulated materials in various industries. However, toxicological and epidemiological studies focusing on the adverse effects of RCFs were still insufficient, particularly in China. We conducted a cross‐sectional study to evaluate comprehensively the associations between occupational exposure to RCFs and respiratory health effects among Chinese workers. We measured and calculated cumulative RCFexposure levels of RCFs workers from the biggest RCFs factory in China. In total, 430 RCF‐exposed workers and 121 controls were enrolled in this study. Physical examinations of the respiratory system were performed and serum levels of biomarkers including Clara cell protein 16 (CC16), surfactant protein D (SP‐D), transforming growth factor β1 (TGF‐β1), and 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) were determined among all subjects. RCF exposure workers showed a higher prevalence rate of respiratory symptoms (cough: 11.9%) and lower levels of small airways function indices (V50%: 82.71 ± 20.01, maximal mid expiratory flow (MMEF)%: 81.08 ± 19.56) compared with the control group (cough: 5.0%, V50%: 90.64 ± 24.36, MMEF%: 88.83 ± 24.22). RCFs workers showed higher levels of TGF‐β1 (31.04 ng/mL) and 8‐OHdG (130.72 ng/mL) and lower levels of CC16 (3.68 ng/mL) compared with the controls (TGF‐β1: 26.63 ng/mL, 8‐OHdG: 106.86 ng/mL, CC16: 5.65 ng/mL). After adjusting for covariates, cumulative RCF exposure levels showed significant positive associations with the levels of TGF‐β1 and 8‐OHdG and negative association with the level of CC16. Occupational RCF exposure could induce adverse respiratory health effects, including cough and small airways damage, which may correlate to the altered levels of lung damage markers (CC16 and TGF‐β1) and oxidative markers (8‐OHdG).