Cows and Air Quality

From last month's Sacramento Bee (Edie Lau, Feb. 27th: no link available), a new study shows cows generate less smog-producing gases than previously estimated:

[Measurements by Frank Mitloehner, UCD animal scientist and air-quality specialist,] show a cow produces about 6.4 pounds of volatile organic compounds (VOCs) per year. VOCs are ingredients in the development of ground-level ozone, a scourge of Central Valley air.

In their estimates, California air board staff have figured that a cow produces 12.8 pounds of VOCs a year - a flawed figure that was based upon a misinterpretation of a study done in 1938.

This study reminds me of the mid-80's, when my Air Chemistry professor at University of Arizona in Tucson, George Dawson, was trying to get a sample of pure biogenic methane to do some Carbon-14 analyses. They have these cows at the University's Campbell Farms with portals leading into the cows' gut. The portals are sealed with rubber flaps. By his telling, to get pure biogenic methane, you sidle up to a cow, open the rubber flap, reach deep inside, and tank up! Continuing with the recent study, though:

...Mitloehner said the most surprising finding so far is that when the cows are removed, and their manure left behind, VOC levels drop to near background levels.

"At the time that the animals were chewing their cud, when they were belching, we saw the peaks (in gas emissions)," he said. "That indicates the gases...are released when the animal ruminates."

The rumination "is going to be very tough to mitigate," said Michael Marsh, head of the trade association Western United Dairymen.

"I don't know what kind of device you might come up with," he said with a wry laugh. "Maybe some antacids."

Over at B3ta, contributor "Kris Fucking Kristofferson" takes liberties with recent song lyrics to express sympathy for the Central Valley's cow-control air pollution dilemma. Kris' message is more poignant given the recent demise of Hunter Thompson:

We had two bags of grass, seventy-five pellets of chloroplast, five sheets of high powered blotter granum, a saltshaker half-full of mesophyll, and a whole galaxy of carbons, fibres, vitamins, proteins... Also, a quart of chlorphyll, a quart of thylakoid, a case of oxygen, a pint of raw carbon dioxide, and two dozen stomates. The only thing that really worried me was the Oxygen. There is nothing in the world more helpless and irresponsible and depraved than a cow in the depths of a photosynthesis binge.