[ad_1] Lawmakers from both parties plan to introduce a sweeping bill in Congress on Wednesday that would force the military for the first time to track and limit troops’ exposure to damaging shock waves from firing their own weapons. Routine exposure to blasts in training and combat was long thought to be safe. But research suggests that over time, exposure to repeated blasts can cause microscopic brain injuries that lead to profound mental problems, like mood swings, insomnia, substance abuse, panic attacks and suicide. The bill, known as the Blast…