SAN JOAQUIN COUNTY, Calif. -- A study that involves dairy cows and a bio-bubble is under way at the University of California, Davis.

Researchers are trying to determine how much air pollution cows generate. To help them measure emissions, the bovines are being housed in some very strange looking pens.

In a first-of-its-kind study, researchers have built what they call "bovine bubbles." Inside, cows go about their daily business, but outside, researchers are measuring everything.

Hank Van Exel says he isn't sure how much money he'll be spending to reduce air pollution at his two San Joaquin County dairy farms, but he knows it will be a lot. He says he's not worried about the money, but he is worried what he's being asked to do won't work.

"I want to clean up the air problems myself. I've never had asthma. I'm getting asthma. But I think maybe we're throwing rocks at the wrong building here," Van Exel said.

Like many Central Valley dairy farmers, Van Exel is in an awkward position. For the first time, California regulations are cracking down on air pollution caused by livestock. But Van Exel says the data on how much pollution a cow produces dates back to a study done in 1938. The numbers from that study indicate that within the next few years, cows in California will be emitting more air pollution than passenger cars, accordig to Vanb Exel.

UC Davis researcher Frank Mitloehner says that statistic is ridiculous.

"Because that study is being used, the dairy industry is the second largest polluter in California right now," Mitloehner said.

Mitloehner says the older science is wrong, and he's created the bovine bubbles to prove it. In each of the airtight pens are 10 Holstein cows. Air goes in from one location and is tested on the way out.

One pen is set up just like any dairy operation, with nothing to control dust on the ground. The other three pens have different treatments on each floor to handle waste products. One uses rice straw.

"The feces stays on top, and the urine goes to the bottom. Urine and feces, if they don't mix, ammonia is not formed. Ammonia is formed when urine and feces mix," Mitloehner said.

Mitloehner expects that the closely monitored bio-bubbles will help gauge the correct amount of pollution created by dairy cows and help discover ways to reduce emissions.

Van Exel says the bottom line for him is he doesn't want to waste any time or money on pollution control until he knows for sure how much his farm contributes to the problem.

"I know some of their science they're using now is not correct. I think all you have to do is drive over the Altamont Pass, and you know where our valley problem is coming from," Van Exel said.

The current experiment will last eight months. Researchers will then move on to study how a cow's feed affects emissions.