text:  When their brains are impaired by lead poisoning, they have a harder time avoiding cars. Federal agencies and outside researchers think ammo is the most likely culprit, but there could be others. Some experts noted cases of poisoning were most common during hunting season. Federal efforts to ban lead ammo have so far failed in Congress. For lead intoxication, we're going to be starting them on a lot of different medications that basically pull the lead out of the blood so they can excrete it themselves.