LDH activity in BALF at 4 h, 14 h, 1 d, 3 d, 10 d, and 30 d after 2.0 mg/rat ITI exposure to MMA-SS or GMA-MS welding fumes. Vehicle controls received saline. (n = 4–6; values are means ± standard error; *significantly different from saline control, p<0.05; #significantly different from saline control and GMA-MS groups, p<0.05).