Phase II Study: Methacholine Challenge Test
36% of the exposed participants and 27% of the control participants had abnormal methacholine challenge testing (MCT) results
highest risk of having an abnormal MCT result was found among males (27% of the exposed and 13% of the controls), those without respiratory symptoms before the accident (31% and 14%, respectively), and those with preexisting asthma (100% and 36%, respectively)
33% of exposed and 25% of control participants did not complete the test