I still use lead and I see no real reason to change.
The concern with lead in fishing is mainly in the shallow parts of lakes where diving birds, can eat lead shot OR can eat fish that have eaten lead shot. The bird at greatest risk are loons that dive and eat fish. But loon populations in my state of Wisconsin continue to grow.
The second concern are eagles and osprey that can eat a fish that has eaten lead split shot. The great majority of these are due to bait fishers that place a sinker right next to the hook and the fish swallows the hook, bait and sinker. Again bald eagle populations in Wisconsin are growing and most deaths are due to cars hitting eagle feeding on dead animals next to highways and eating bullet lead from gut piles left by hunters. Eagles are so populous in Wisconsin now that they are being crowded out from nesting and feeding on water to nesting and feeding on road kill.
I have yet to see a loon feeding on a river. I suppose an eagle could grab a trout that happens to have swallowed a nymph that has lead wire, but how likely is that? How likely is it for you to have fish swallow a nymph and then have that fish taken and eaten by an eagle and have that eagle eat the fly while feeding on the fish? D*mned rare, I would think.
The largest killer of eagles are cars.
"DNR staff and volunteers recovered all sick, injured, or dead eagles in 2011. The leading cause of death was collision with a vehicle. Most vehicle collisions occurred when eagles were scavenging car-killed deer."
Following the same "ban the lead crowd" logic to save eagles by banning lead, lets ban cars instead. They are the greatest killer of eagles. You like eagles? Try walking to Montana.
Sorry about the rant, but the banning lead in tying flies is idiotic to the extreme.