Effects of CeO2 on DEP induced lung inflammation, cytotoxicity, air/capillary damage and ROS generation by AM. Effects of CeO2 on DEP-induced PMN inflltration, a measure of lung inflammation (A), LDH activity, a marker for the cytotoxicity (B), the amount of albumin in the first lavage fluid, an indicator for the leakage of air/capillary barrier (C), and chemiluminescence generated by AM, a measure of ROS generation (D), are presented. The samples were collected at 1 and 28 days post-exposure. *Significantly different from AM control; p < 0.05.