Sure, there's plenty of steam coming from the stacks and it's easy to point to.
There is also fine particulate hydrocarbon (tar) that settles on things and makes a sticky film. I lived in Taylor Lake Village, next door to Space Center Houston, not far enough from Pasadena, apparently. My car, parked under a carport but with open walls, would get a visible, sticky film on it in a very short time after being washed.
The crap was so pervasive it made it into our air conditioned house and got all over the electrostatic air cleaners - again, covered in tar within days of washing. When we moved to Gainesville, Florida, those same air cleaners would get covered seasonally, with pollen, but the tar from the air of Houston never showed up.