Two major oil companies have asked a Texas judge to dismiss a civil lawsuit that could draw new attention to the toxic air emissions from oil and gas production.

The lawsuit was filed last year by Mike and Myra Cerny, who say they can't enjoy the use of their home because of the benzene, toluene and other toxic chemicals released from nearby facilities owned by Marathon and Plains Exploration & Production (PXP). The Cernys are using the same argument that helped another Texas family, Bob and and Lisa Parr, win a groundbreaking, $2.9 million judgment against Aruba Petroleum last April: That the emissions created a nuisance that made their lives unbearable.

Air emissions are increasingly recognized as a problem in drilling areas throughout United States, with residents complaining of coughing, headaches, nosebleeds, rashes and dizziness. But lawsuits linking gas and oil production to health problems have been considered almost unwinnable, because few scientific studies have been done on how the industry's emissions might affect human health.

Jane Barrett, director of the University of Maryland's Environmental Law Clinic, said that if the Parrs and Cerneys succeed, their cases could change the assumption that ordinary people can't stand up to the industry.

Barrett compared the two Texas cases with early lawsuits filed against the tobacco industry, which was once seen as immune to charges that it was responsible for the harmful effects of cigarettes.

"People swore it would never happen in the tobacco industry and it did," Barrett said. "Now the oil and gas industry has to be taking a look at that same big picture, knowing that it could happen in their industry.

"It's a snowball they don't want to see start rolling."

Aruba Petroleum spelled out its concerns in a motion it filed last week, asking for a new trial in the Parrs' case. "The judgment thus threatens to establish a startling new precedent in Texas—a precedent allowing juries to award millions of dollars for non-Havner claims arising from the lights, sounds, and odors created in the normal course of oil and gas drilling," according to the Aruba motion.

Under Texas law, a non-Havner claim is one in which the plaintiffs don't claim to have suffered a specific disease or injury—so they aren't required to present scientific or medical proof to substantiate their allegations. The non-Havner claims by the Parrs and the Cernys assert only that the emissions created a nuisance that has caused them discomfort.

Marathon and PXP have asked a judge to dismiss the Cernys' lawsuit, saying the couple and their son offered no medical or scientific proof that they were harmed by the emissions. A hearing in Karnes County District Court is scheduled for Thursday. The couple has asked for more than $1 million in damages, money they have said would allow them to buy a home away from the drilling.

Meanwhile, two other Karnes County families have filed lawsuits alleging that emissions have destroyed their lifestyles.

Despite the Parrs' legal victory, the Cernys have a huge hurdle to overcome, said Thomas McGarity, a University of Texas law school professor who specializes in environmental and administrative law.

"To show they were exposed to the chemicals and they have the symptoms isn't sufficient," he said.

"It is not enough to say the emissions could have caused the harm; they have to prove they more likely than not caused the illness."

It's like someone suffering from hay fever saying ragweed caused the sniffles when it could have been just as likely dandelions that caused the symptoms, he said.

"All the defendants have to do is point their finger at another possible source," he said.

But William Anaya, a Chicago attorney who often represents the oil and gas industry, thinks Marathon's motion mischaracterizes the case. He believes the motion will fail, because Texas law doesn't require the Cernys to provide expert opinions to prove they've been by affected by the nuisance created by the emissions.

Anaya, who is not involved in the case but has reviewed the documents, thinks a more direct defense should be mounted showing the facilities were not responsible for the emissions. "My question is—and it's rhetorical—why isn't the response by the industry here 'We have the data that shows we didn't create the problem," he said. "It makes me wonder if they have the evidence they did not create the problem."

'We're Going to Get It'

The Cernys were among the first to complain publicly about the air quality in the 26-county Eagle Ford shale region, one of the nation's most active oil drilling areas. Before they spoke out, the news coming out of the hardscrabble swath of Texas consisted almost entirely of glowing predictions of wealth.

The couple bought their small house on a one-acre lot in rural Karnes County in 2003, hoping to escape the bustle of San Antonio and the annoyances that come with big city life. Like many of their neighbors, the unemployed truck driver and partially disabled wife were happy to lease their mineral rights to oil companies in 2012, when the drilling boom expanded to their neighborhood.

The Cernys signed a lease with Marathon. No drilling facilities were built on their land, but three wells were drilled nearby to syphon oil from their property. By 2013, their house was surrounded by dozens of oil and gas wells, petroleum storage tanks and smoking flares, including facilities owned by PXP.

The Cernys no longer grant interviews. But in a June 2013 interview with InsideClimate News and The Center for Public Integrity, Myra Cerny said she and her husband and their teenage son began getting nosebleeds, rashes, pounding headaches and nausea.

With their home surrounded by oil and gas operations, "no matter which way the wind blows, we're going to get it," she said.

She recalled one incident when a particularly foul petroleum odor invaded their home.

"I couldn't even gather my thoughts," she said. "You felt like you were going to throw up. It's like you were standing in a bug bomb, almost—the smell got that bad...You thought if you laid down you weren't going to get back up."

Cerny said that at first they assumed state regulators would protect them from the noxious emissions.

"We went on blind faith: [operators] couldn't do it if it wasn't safe," she said. "We didn't understand that, oh yeah, they can. They get their permits and they're basically, as far as I'm concerned, above the law that everybody else has to follow."

In August 2012 the Cernys complained to the Texas Commission on Environmental Quality about sulfur and petroleum odors. According to a TCEQ report obtained by InsideClimate News and the Center for Public Integrity, inspectors found that a Marathon processing facility was releasing more than a dozen compounds, including benzene, hydrogen sulfide, toluene, and xylene that exceeded the maximum emission rate allowed by Texas law. Marathon was cited for not promptly reporting the excessive emissions and for having a non-operating flair, according to the report.

But the lawsuit said the problems continued.

"In its pursuit of oil and gas, the defendants have continuously released strong odors and noxious chemicals into the environment," the lawsuit said. "The nuisance has caused injury to both the plaintiffs' land and to their persons."

Marathon and PXP contend the Cernys have no evidence that emissions from their operations caused the family's health problems or ruined their lives.

"They make this assertion without providing a single expert on oil and gas operations who has opined that [Marathon] has done anything wrong or a single medical expert who has opined that those operations have caused them any injury," according to the Marathon motion.

The Cernys also allege that when the Marathon wells were fracked—a step that releases explosions deep in the earth—cracks appeared in the ceiling, walls and foundation of their home. The companies say those defects predated any drilling or fracking.

Marathon claims that the Cernys have benefited from the drilling, earning more from their Marathon lease than from any other source of income.

Marathon and PXP also insist the family's poor health is due not to oil or gas emissions, but to years of smoking, heavy use of prescription drugs and "chronic marijuana use" by their son.

"Given these histories, it is not surprising that there are no treating physicians or medical experts in this case that attribute the Plaintiffs' symptoms to [Marathon's] activities with a reasonable degree of certainty," according to the motion.

But the Cernys' attorney, Tomas Ramirez is confident the motion will fail because it misses the point of his case. His clients aren't claiming that the emissions caused a specific disease or injury, he said. Instead, they say they caused common, everyday complaints that created nuisance conditions at their home.

"When you tell a jury: 'This is what I smelled. Here are the sources and this is what happened to me; 'then it's an easy path to follow," Ramirez said in an interview. "You don't need an expert to explain a runny nose."

$2.9 Million Award 'Excessive'

While Marathon and PXP are trying to block the Cernys' case from going to trial, Aruba Petroleum is fighting to overthrow the lawsuit it lost to the Parr family, who live near Fort Worth in the Barnett Shale. A hearing on the motion is scheduled for Aug. 29.

Aruba contends one of the jurors should have been excluded because of a 1994 misdemeanor criminal record for theft, which in Texas prohibits people from serving on juries.

The 38-page motion contends "the Parrs' symptoms—such as headaches, nosebleeds, and nausea, among others—are common in the general population and could have been caused by any number of conditions or events." It also argues that the $2.9 million the jury awarded the family is excessive. The company cites two recent nuisance judgments against other oil and gas companies that awarded the plaintiffs $36,000 in one case and $20,000 in the other.

This story is part of an ongoing project by InsideClimate News and The Center for Public Integrity. Jim Morris, with the Center for Public Integrity, contributed to this report.

Correction: An earlier version of this story misnamed the court that was scheduled to the case to dismiss the Cerny family's lawsuit. It is Karnes County District Court, not Karnes County Justice Court.

Update: On August 14, 2014, District Judge Stella dismissed the lawsuit filed by the Cerny family.