Is the outdoor air safe at Devonshire Park?

Yes, the outdoor air is safe. If you want to look at the instrument itself (PTR-MS) and the inside of the van it's at:
Web Link
and hit View Video at the bottom

Let's remember that TCE is also present in some household cleaning products, in some adhesives and other materials used in home construction and furniture, etc., so measuring TCE in the air inside a home does not always mean that it originates from underlying groundwater. Soil vapor samples from beneath the affected homes would add an important piece of the puzzle. Results will also vary over time, so if EPA does confirmation testing and finds no detections, it only means it wasn't in the air on the day they tested. The duplicate samples taken by the firm with the new technology will be more informative.

What is the risk of this exposure compared to inhaling uncombusted gasoline compounds like benzene from car exhaust on 101 that blows south into residential neighborhoods? Very small, I think. It's good to be concerned about all exposures and control those we can, focusing on the largest first. Our attention is focused on trace TCE because someone is testing for it, but we should look at the big picture, and don't forget exposures from the food we eat.

Yes, Thomas, good points, there are other sources and a good check of what's in the home can answer that. Good soil vapor analyses are needed. As Lenny and Daniel point out, for this vapor issue, good ventilation is key. And, yes, risk is always relative, doesn't matter whether one is discussing chemical exposure, driving a car while texting, or background radiation.

@Thomas - in this case, it's pretty clear where the TCE is coming from. And as stated in numerous articles about TCE in the neighborhood - the outside air is cleaner.

does anyone have information regarding any class action over the whole Evandale mess? I lived across from 175 for 12 years and I am significantly worried about future health problems from the plume.

@Steve- You can never be totally sure of the source unless you test the sub-slab soil vapor. If TCE is not present in the vapors beneath the home, then the TCE is more likely originating from an indoor air source. Your home can be in an area with contaminated groundwater and vapor intrusion may not be occurring, while two houses away there may be an issue. Being that TCE was higher in the 2nd floor as compared to the first also indicates there could be some background indoor sources (e.g., drycleaned clothes)as one would expect the concentration to attenuate as vapors rise from the sub-slab to the basement, 1st floor, and 2nd floor, etc. Very interested in this sampling device though. Were sub-slab readings collected at this home?

Was this an April Fool's joke?

My! I hope that it will not cause more destruction than it already have.

- Bill H. Amend, Web Link