Respiratory health and inflammatory markers - Exposure to respirable dust and quartz and chemical binders in Swedish iron foundries

PurposeTo study the relationship between respirable dust, quartz and chemical binders in Swedish iron foundries and respiratory symptoms, lung function (as forced expiratory volume FEV1 and vital capacity FVC), fraction of exhaled nitric oxide (FENO) and levels of club cell secretory protein 16 (CC16) and CRP.MethodsPersonal sampling of respirable dust and quartz was performed for 85 subjects in three Swedish iron foundries. Full shift sampling and examination were performed on the second or third day of a working week after a work free weekend, with additional sampling on the fourth or fifth day. Logistic, linear and mixed model analyses were performed including, gender, age, smoking, infections, sampling day, body mass index (BMI) and chemical binders as covariates.ResultsThe adjusted average respirable quartz and dust concentrations were 0.038 and 0.66 mg/m3, respectively. Statistically significant increases in levels of CC16 were associated with exposure to chemical binders (p = 0.05; p = 0.01) in the regression analysis of quartz and respirable dust, respectively. Non-significant exposure-responses were identified for cumulative quartz and the symptoms asthma and breathlessness. For cumulative chemical years, non-significant exposure–response were observed for all but two symptoms. FENO also exhibited a non significant exposure-response for both quartz and respirable dust. No exposure-response was determined for FEV1 or FVC, CRP and respirable dust and quartz.ConclusionsOur findings suggest that early markers of pulmonary effect, such as increased levels of CC16 and FENO, are more strongly associated with chemical binder exposure than respirable quartz and dust in foundry environments.

研究目的：探究瑞典铸铁厂内可吸入粉尘（respirable dust）、石英（quartz）与化学黏合剂（chemical binders）的暴露水平，与呼吸道症状、肺功能[以用力呼气量1秒值（forced expiratory volume, FEV1）及用力肺活量（vital capacity, FVC）为指标]、呼出气一氧化氮分数（fraction of exhaled nitric oxide, FeNO）以及俱乐部细胞分泌蛋白16（club cell secretory protein 16, CC16）与C反应蛋白（C-reactive protein, CRP）水平之间的关联。
研究方法：对三家瑞典铸铁厂的85名受试者开展可吸入粉尘与石英的个体采样。于周末休息后的工作周第二或第三天开展全班次采样与检查，并在第四或第五天追加采样。采用logistic回归、线性回归及混合效应模型开展分析，将性别、年龄、吸烟情况、感染状况、采样日期、身体质量指数（body mass index, BMI）及化学黏合剂作为协变量纳入模型。
研究结果：校正后的可吸入石英与粉尘平均浓度分别为0.038 mg/m³与0.66 mg/m³。在石英与可吸入粉尘的回归分析中，CC16水平的统计学显著升高分别与化学黏合剂暴露相关（p=0.05；p=0.01）。累积石英暴露以及哮喘、气促症状未呈现显著的暴露-反应关系。对于累积化学接触年限，除两项症状外其余症状均未观察到显著的暴露-反应关系。FeNO在石英与可吸入粉尘暴露中同样未呈现显著的暴露-反应关系。FEV1、FVC、CRP与可吸入粉尘、石英之间未发现暴露-反应关系。
研究结论：本研究结果提示，肺部损伤早期生物标志物（如CC16水平升高与FeNO水平升高）与化学黏合剂暴露的关联强度，高于其与铸铁厂环境中可吸入石英及粉尘的关联。