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

by Lena Andersson, Ing-Liss Bryngelsson, Alexander Hedbrant, Alexander Persson, Anders Johansson, Annette Ericsson, Ina Lindell, Leo Stockfelt, Eva Särndahl, Håkan Westberg

To 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.

Personal 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.

The 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.

Our 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.