Bonn, May 9 : Between 400,000 and 1.5 million waterbirds alone die in Europe annually from ingesting lead and there is a need to phase out lead, a UN body said on Wednesday.
The number of additional birds suffering health problems because of poisoning by lead ammunition is at least as large as the number killed by lead shot every year.
"Lead poisoning the world over is not only killing millions of birds.
Lead in our environment is also an issue of human health which urgently needs to be addressed," said a statement quoting the UN Convention on Migratory Species (CMS) Executive Secretary Bradnee Chambers.
World Migratory Bird Day is a two-day event annually held on the second weekend of May.
This year's theme is "Unifying our Voices for Bird Conservation".
Among the significant but often underestimated threats to migratory birds across the African-Eurasian Flyways -- the major bird migration corridors which links Europe, Africa and Western Asia -- is lead poisoning.
The UN Convention on Migratory Species (CMS) and the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA), two international environment treaties behind World Migratory Bird Day, are also driving international efforts to tackle this global threat.
Lead poisoning is caused when lead is released into the environment.
Lead is a highly toxic heavy metal that is used for both fishing weights and hunting. When fired from a shot gun, hundreds of lead pellets fall into the wider environment putting wildlife at risk.
While habitat loss, pollution, unsustainable harvest and agricultural practices, illegal killing and trapping as well as collision and electrocution by power lines are among the greatest dangers to migratory birds, lead poisoning is one of the threats for which there is a practical solution.
Waterbirds and other birds see lead shot or lost fishing weights and pick them up either as food or mistaking them for grit.
They die directly from poisoning or the ingested lead affects their immunity, behaviour and reproductive capacity.
Raptors and scavengers pick up the lead shot or fragments of bullets in the prey or carrion they eat.
Lead left in the environment contaminates soils, and people are exposed when they consume lead-shot game.
Lead-free ammunition is now available and has been demonstrated by research and in practice to be effective.
Many hunters already use non-toxic ammunition. Some countries such as Denmark and the Netherlands have completely phased out all lead shot.
AEWA was the first international treaty to focus on addressing the problem of lead ammunition.
AEWA Executive Secretary Jacques Trouvilliez said: "The treaty has called for a political commitment to phase out lead in wetlands and many countries responded to the appeal.
Now we need legally binding measures at country level to stop hunting with lead shot."