Silver nanoparticles induced cytokines and chemokines production in normal human lung fibroblasts (IMR90). The graphs indicate the production of cytokines and chemokines in pg/ml (mean ± SD) by normal human fibroblasts after incubating with 400 μg/mL of silver nanoparticles for a period of 48 hours. The cytokine levels were measured in untreated cells (Control) and in cells treated with silver nanoparticles (treated (Ag-np)). Statistical significance was determined between untreated and treated samples using Student's t test. *p value ≤ 0.05.