Figure 1.

Long-term exposure to PM_2.5 does not affect proliferation or cellular viability but increases intracellular reactive oxygen species (ROS). BEAS-2B cells were cultured in the presence of 100 µg/mL PM_2.5 for three to five weeks as described in the materials and methods section. (a) Cells were detached by trypsin, analyzed by a trypan blue exclusion assay, and counted in a Neubauer counting chamber using a light microscope. Only viable cells were considered and were depicted as fold increase in cell number compared to plated cells (n = 3). (b) Cellular viability was determined by an MTT assay (n = 3). (c) For quantification of intracellular ROS, 2′,7′-dichlorofluorescein diacetate (DCFH-DA) labeled cells were analyzed by flow cytometry (n = 3). Cells cultured in the absence of PM_2.5 served as controls. Values are depicted as means and +standard deviations; *** p < 0.001.