Friday, October 29, 2010

CPANA Gets Third Air Quality Benchmark Results

As we've reported before, CPANA is in the process of conducting year-long pre-drilling air quality benchmark study. We recently received results from the third month of monitoring.

CPANA uses a stainless steel sorbent tube placed in a secured location outdoors in Southern Lewisville, just down-wind from a future drill site. The tube passively soaks up contaminants from the air and is exposed for about a month. After exposure, the tube is sealed up and shipped to a laboratory where it is analyzed by thermal desorption - gas chromatography / mass spectrometry. The group is looking for the concentration of Benzene, and the top 9 other volatile organic compounds (VOCs).

The following compounds and concentrations were found for the sampling period of 9/19/2010 - 10/18/2010:

Benzene was not detected. The limits of detection for this sample puts benzene below 0.05 ppb.

Isopropyl Alcohol was detected at 0.23 ppb. This is standard rubbing alcohol used for medical procedures and as a household solvent or astringent. It can also be used as a fuel additive.

Acetic Acid was found at 0.15 ppb. Commonly known as vinegar, but also used in industry as a feedstock. It can be found in nature as a fermentation byproduct of fruit spoilage. It may be used as a household cleaner or used in food preparation.

Cyclohexanone was found at 0.13 ppb. A chemical precursor to the manufacture of nylon, this compound is a product of the oxidation of cyclohexane. LTESL (health) = 20ppb, under review.

p-Xylene was found at 0.10 ppb. This solvent is similar to Benzene, but with two additional methyl groups added. The ortho, meta, and para isomers (the o, m, or p prefix) indicate where on the molecule the methyl groups are added. According to CDC, xylene is also found in automobile exhaust, and comes from industrial sources. LTESL (health) = 42 ppb for all 3 isomers.

Pinene was found at .07 ppb. (This is a natural compound from pine trees, which are located near our sample box)

Dodecane was found at 0.03 ppb. This is a 12 carbon alkane hydrocarbon that is a component of diesel and aviation fuel. LTESL is 350 µg/m3

Isocyanato Cyclohexane was found at 0.03 ppb. A yellowish liquid with an irritating odor. Insoluble in water. Flash point 127°F. Very toxic by inhalation, skin absorption and ingestion. Used to make pharmaceuticals and agricultural chemicals. LTESL (health) is 0.4 ppb.

Tridecane was found at 0.03 ppb. This is a 13 carbon alkane hydrocarbon that is a component of diesel and aviation fuel. It is also naturally produced by some stinkbugs as a defense. (Note that our sample box has screen to keep insects out, and we check for insects when we change tubes). LTESL is 350 µg/m3

No other compounds were detected in this sample. Concentrations are given in parts per billion (ppb). Overall MOU (margin of uncertainty) is +/- 16.8%.  Laboratory results are attached.