nah. they are probably from pollution, but never mind. I don't know enough about Chinese geography to see if there could be a link, and the flu seems to have come from infected pigeon droppings in an open air market.
The Agriculture Ministry confirmed late Thursday that the H7N9 virus had been detected in live pigeons on sale at a produce market in Shanghai. The killing of birds at the Huhuai market in Shanghai started Thursday night after the city's agricultural committee ordered it in a notice also posted on its website.
it's not clear if the pigeons were alive or dead, wild pigeons caught for sale or those raised for food or to be used as pets/homing pigeons.