Lanell Anderson takes to the road early this warm spring morning for a tour of Houston real estate. Perfectly coiffed and smartly turned out in a black pantsuit and a black Lexus, cell phone bleating every few minutes, Anderson is an independent real estate agent — seven closings this month alone. But we are not taking a standard home tour today. As we head north on a high bridge over Buffalo Bayou, the Houston Ship Channel sprawls ahead in all its petrochemical glory. It is this horizon-spanning complex of refineries, power lines and chemical factories that makes the Texan economy bigger than all but ten of the world's sovereign nations.

The sight is literally breathtaking. An odor like cat urine seeps through the Lexus' advanced AC and filtration system. "That would be caused by acrolein," Anderson says. It's one of hundreds of toxic chemicals routinely discharged into the region's air by some 300 facilities. Xylenes, styrene, 1,3-butadiene, methyl isocyanate — Anderson tosses off the names of carcinogens, mutagens and just plain bad-to-breathe gases. Her knowledge is born of volunteering for the last ten years with citizens' environmental groups across Texas.

A tall plume of black smoke billows from a refinery. "They call that an 'upset,' " Anderson explains — "venting something they can't control and burning it off into the atmosphere. The black smoke is when the chemical just overwhelms the pilot flame that's supposed to burn it. Lots of upsets around here."

She turns the Lexus down a residential street on Houston's east side that has clearly seen better days. She slows down by her old home, the one she bought in 1981 "because we could afford a bigger lot out here. I remember the chemical odors, so strong that two or three times a year they would awaken me out of a sound sleep at night."

Anderson's parents lived nearby, until her mother died of bone cancer and her father succumbed to respiratory disease. She and her two sisters all struggle with a variety of autoimmune and respiratory diseases. "I wonder, if I had only known more, could I have somehow protected my family?" she asks. "Do I believe what's happened to us is from the air pollution? Yes. Is it provable scientifically? That would take a lot of time and money. Am I bitter? You're damn right."