The Clean Air Pomona website says it best:
"Currently, 38 other cities in LA County and 16 across the San Gabriel Valley enjoy smoke-free parks.
Pomona is a beautiful and vibrant community that should NOT be the exception!"
I can't speak for other parks, but I know in Lincoln Park there are too many times when the cigarette smoke blows from the west part of the park into the playground area. Plus there are tons of butts, put out in the leaves and needles right next to the tree trunks.
If you would like to stay informed about Clean Air Pomona's continued efforts, you can email them from their website.