Fig. 4

Mineral particles induce release of pro-inflammatory cytokines in human bronchial epithelial cells. HBEC3-KT cells were exposed to 0–400 µg/mL Na-feldspar, K-feldspar, Ca-feldspar, biotite, epidote, hornblende, actinolite, augite, quartz and orthopyroxene for 24 h. The release of CXCL8 (A and D), IL-1β (B and E) and IL-1α (C and F) in the cell culture supernatant was measured by ELISA. Results are presented as mean ± SD (n = 4–6). Area under the curve (AUC) values in D–F were calculated from the values in A–C for the concentration-range of 0–200 µg/mL. Statistical significance is based on a two-way ANOVA followed by Dunnet’s post-test (A–C) or a one-way ANOVA followed by Tukey post-test (D–F). Values in A–E were log-transformed prior to statistical analysis to satisfy model assumptions. Asterisks (*) indicate statistically significant difference from the respective control (A–C), while a capped line indicates statistically significant difference between samples (D–F)