pigeon poo can be very dangerous. cold, i hope you are ok.
PIGEON poo was last night being blamed for the collapse of a bridge that killed 13 people.
Experts believe a build-up of corrosive droppings weakened the metal structure in Minneapolis, USA.
It then buckled under the pounding of heavy traffic and finally collapsed on August 1, plunging cars into the Mississippi River.
Neal Langerman, of the health and safety division of the American Chemical Society, said: �Pigeon droppings contain ammonia and acids. Over a long term, it might cause structural weaknesses.�
He explained that the potent poo dries out and turns into a concentrated salt. When water gets to it, small electrochemical reactions take place that rust the steel underneath.
Inspectors reported there was a coating of pigeon dung on the Interstate 35W bridge as long ago as 1987.