Positive Rates and Factors Associated with Abnormal Lung Function of Greenhouse Workers in China: A Cross-Sectional Study

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

Biomarkers for Pulmonary Inflammation and Fibrosis and Lung Ventilation Function in Chinese Occupational Refractory Ceramic Fibers-Exposed Workers

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

Elevated level of urinary tellurium is a potential risk for increase of blood pressure in humans and mice

Background: People worldwide are routinely exposed to tellurium mainly via dietary ingestion. There has been no study to clarify the contribution of tellurium to blood pressure in humans or animals. Methods: In this cross-sectional study conducted in a general population of 2592 residents in Japan, the associations of urinary tellurium levels with blood pressure and prevalence of hypertension were investigated. The potential sources of tellurium were also investigated. An interventional study in mice confirmed the effect of tellurium exposure on blood pressure. Results: Linear and logistic regression analyses with consideration of confounders including urinary sodium–potassium ratio showed significant positive associations of urinary tellurium level with prevalence of hypertension and blood pressure. Cereals/beans and vegetables/fruits were determined to be potential dietary sources of tellurium exposure. Intermediary analysis suggested that increased intake of cereals/beans, but not that of vegetables/fruits, is positively associated with the tellurium-mediated risk of hypertension. Correspondingly, the mouse study showed that exposure to a putative human-equivalent dose of tellurium via drinking water increased blood pressure with an elevated level of urinary tellurium. The temporally increased blood pressure was decreased to the normal level by a break of tellurium exposure with a reduced level of urinary tellurium. Conclusions: The interdisciplinary approach provided the first evidence that tellurium exposure is a potential risk for increase of blood pressure. Since the human urinary tellurium level in this study is comparable with the levels in general populations in other Asian and European countries in previous studies, exposure to tellurium may be a latent universal risk for hypertension