Air Quality in the Barnett Shale - Part 11: Is there a real concern for DISH, Texas?

So what do we know so far regarding the real health concerns for the citizens of the Town of DISH, Texas?:

• Benzene and other chemicals were found in the seven samples collected during one 24 hour sampling event conducted by Wolf Eagle Environmental.
• The TCEQ has sampled the air in the Town of DISH, Texas and reports hourly values below the short-termAir Monitoring Comparison Values (AMCV)  
• The TCEQ has sampled the air in the Town of DISH, Texas and reports hourly values below the short-termAir Monitoring Comparison Values (AMCV)  

Here is what I gathered from the TCEQ website for air monitoring at DISH, Texas:

Note: Report generated on Dec 16, 2010.  Monthly and Yearly data reported for BTEX.

As you can see, the amount of BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) is under the AMCV for each chemical.  That's a good sign.  But lets make the assumption that the 24 hour results reported by Wolf Eagle Environmental are what the citizens of DISH, Texas are being exposed to on a regular basis.  Would there be a health concern?

That's a difficult one to make a call on.  In fact it is so uncertain that even Wolf Eagle Environmental and Wilma Subra in any of their reports do not make any claim what-so-ever as to these levels creating a undo health risk.  All that is said is that they exceed the ESL for some of the chemicals found.

The TCEQ, on the other hand, does state:

"24-hour air monitors in the Barnett Shale area are showing no levels of concern for any chemicals." and "there are no immediate health concerns from air quality in the area" and "that when they are properly managed and maintained, oil and gas operations do not cause harmful excess air emissions.”

Now I know better than to rest my case on one set of data.  However, I have at my disposal - and anyone clicking the links I cite does as well - a whole bunch of data or 'n'.  This gives me more confidence to agree with the statement TCEQ has issued above.

There is one more issue in play that leads me to conclude that the air is safe and that the folks in the Town of DISH, Texas are not going to experience " health concerns from air quality in the area."

Exposure is but one step of the K.C.Donnelly Risk Paradigm I discussed in Part 2.

What needs to happen after exposure to a chemical takes place is uptake.  That is, the chemical has to enter into the body where the dose, time, and pharmacokinetics now come into play.

The question becomes, OK, if they are exposed, how much are they actually getting into their system?  In order for a health effect to manifest, uptake must take place.  And if uptake has taken place, we can measure the actual concentration of the chemical in the blood stream or tissue.

And wouldn't you know it, that has been done.

Much of the concern about natural gas operations has been centered in DISH, so in early 2009, the Texas Department of State Health Services performed blood tests on 28 DISH residents (representing about 13 percent of the town’s population).

Test results showed that the exposure of DISH residents to VOCs was similar to that of the general U.S. population, and that exposure to certain contaminants was no higher than that of the general U.S. population.

The study further found that the only residents who had higher levels of benzene in their blood were smokers. Cigarette smoke contains benzene, so finding this in smokers’ blood is not unusual, the department noted. (1)

So now what do we know?

• We know that we have detected chemicals contaminants in the 24 hour samples collected by Wolf Eagle Environmental
• We can assume exposure has taken place.
• We can show - through blood tests - that exposed citizens have levels of contaminants no higher than those of the general US population.

So what can we conclude from all this?  That excluding odor, noise, and catastrophic events, the TCEQ is correct in asserting "that when they are properly managed and maintained, oil and gas operations do not cause harmful excess air emissions.”


Next Post: Air Quality in the Barnett Shale - Part 12: Oil & Gas, it's better if you go green!

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