Houston has had a troubled past with pollution of many types.

The national park has miles of "wilderness" but the air is filled with pollution from the valley.

In the old days they weren't concerned with pollution.

But on certain days, usually those with heavy pollution, they had to do it more often.

The movie deals with environmental destruction, pollution and class struggle.

Phillips Petroleum lost $255 million, also for reasons having to do with pollution.

And from the beginning I have believed there should be a cost associated with pollution.

Most of the buildings were grey or black with age and pollution.

So, if something that won't go away, will be done with less pollution than current levels, well how can you not like that?

Also as they are usually quite far away from the nearest town you get a great view of the night sky with little light pollution.