Quote:
Originally Posted by 8ballrollin
Pigeon droppings contain ammonia and acids, said chemist Neal Langerman, an officer with the health and safety division of the American Chemical Society. If the dung isn't washed away, it dries out and turns into a concentrated salt. When water gets in and combines with the salt and ammonia, it creates small electrochemical reactions that rust the steel underneath."
http://sfgate.com/cgi-bin/article.cg...3D81.DTL&tsp=1 |
How does that compare to the tons of salt they spread on the roads in the winter there?