 The reason is that waterfowl hunting with lead shot was identified as a major cause of lead poisoning in waterfowl, which often feed off the bottom of lakes and wetlands where lead shot collects.In the United States, UK, Canada, and many western European countries (France as of 2006), all shot used for waterfowl must now be non-toxic, and therefore may not contain any lead.One method commonly used to work around this legislative change, at least for hunters with newer shotguns with chokes designed for steel shot, is to use steel shot, but the use of steel shot may damage chokes on older firearms that were designed for use with lead shot only such as Damascus-barreled shotguns.