Kay Allen had just started work, and everything seemed quiet at the Cornerstone Care community health clinic in Burgettstown, Pa. but things didn’t stay quiet for long.

“All the girls, they were yelling at me in the back, ‘You gotta come out here quick. You gotta come out here quick,’ ” said Allen, 59, a nurse from Weirton, W.Va.

Allen rushed out front and knew right away what all the yelling was about. The whole place reeked — like someone had spilled a giant bottle of nail polish remover.

“I told everybody to get outside and get fresh air. so we went outside. and Aggie said, ‘Kay, I’m going to be sick.’ but before I get in, to get something for her to throw up in, she had to go over the railing,” she said.

Nothing like this had ever happened in the 20 years that Allen has been at the clinic. After about 45 minutes, she thought the coast was clear and took everyone back inside.

“It was fine. but the next thing you know, they’re calling me again. there was another gust. well, the one girl, Miranda, she was sitting at the registration place, and you could tell she’d had too much of it. and Miranda got overcome by that and she passed out,” she said.

‘It’s The Unknown I think That’s The Scariest Thing’

This sort of thing has been happening for weeks. Mysterious gusts of fumes keep wafting through the clinic.

In fact, just the day before being interviewed by NPR, Allen suddenly felt like she had been engulfed by one of these big invisible bubbles.

“And all of a sudden your tongue gets this metal taste on it. and it feels like it’s enlarging, and it just feels like you’re not getting enough air in, because your throat gets real ‘burn-y.’ and the next thing I know, I … passed out,” Allen said.

Half a dozen of Allen’s co-workers stopped coming in. One old-timer quit. no one can figure out what’s going on. for doctors and nurses used to taking care of sick people, it’s unnerving to suddenly be the patients.

“It’s the unknown I think that’s the scariest thing,” she said.

Richard Rinehart, who runs the rural clinic, can’t help but wonder whether the natural gas drilling going on all around the area may have something to do with what’s been happening.

“I lay in bed at night thinking all kinds of theories. is something coming through the air from some process that they’re using? I know they use a lot of chemicals and so forth. Certainly that could be a culprit. We’re wondering, is something coming through the ground?” Rinehart said, noting that he’d just noticed a new drill on a hill overlooking the back of the clinic.

Now, no one knows whether the gas drilling has anything to do with the problems at the clinic. it could easily turn out to be something completely unrelated. There’s a smelting plant down the road and old coal mines everywhere.

“Anything could be possible, and we just are trying to get to the root of it,” he said.

Mysterious Symptoms, Lots of Questions

People living near gas well drilling around the country are reporting similar problems, plus headaches, rashes, wheezing, aches and pains and other symptoms.

Doctors like Julie DeRosa, who works at Cornerstone, aren’t sure how to help people with these mysterious symptoms.

“I don’t want to ignore symptoms that may be clues to a serious condition. I also don’t want to order a lot of unnecessary tests. I don’t want to feed any kind of hysteria,” DeRosa said.

To try to figure out what’s going on, the clinic called the Pennsylvania Department of Environmental Protection, which is investigating. it also started testing the air for chemicals, monitoring wind direction around the clinic and keeping diaries of everyone’s symptoms. in addition, the clinic contacted Raina Rippel, project director for the Southwest Pennsylvania Environmental Health Project.

The local nonprofit was set up recently to help people in this kind of situation. Her team tested tap water from inside a men’s room and from a stream out back.

Rippel says she knows people in the area have a lot of questions: “Is my water fit to drink? is the air fit to breathe? Am I going to suffer long-term health impacts from this?”

Connecting Experts in Search of Answers

To try to answer these questions, her project is connecting doctors and patients with toxicologists, occupational health doctors, environmental scientists and other experts.

“People go from physician to physician, because ‘nobody seemed to be able to treat this awful rash that I have,’ or ‘nobody seemed to be able to deal with my gastrointestinal pain that I have.’ and so they go from place to place, trying to find someone who can do that,” said David Brown, a toxicologist who helped set up the project.

The project is also starting to educate doctors about what kinds of tests they can try and what kinds of advice to give. in addition, a nurse practitioner visits and counsels people who are sick.

Dr. Sean Porbin, a private doctor who advises the project, gives the project’s nurse practitioner advice when she needs it. but Porbin is skeptical that many people are getting sick from the drilling, which is commonly called “fracking.” there are about 5,000 new wells in Pennsylvania.

“If it’s true, you’d expect people dropping all over the place based on the amount of fracking that’s going on here. You would look around and see people dropping like flies. It’s not the case. I don’t see anybody affected. and it’s not for a lack of looking,” he said.

Porbin, who like a lot of people in the area has leased some of his land for drilling, wants to make sure no one’s missing more mundane explanations — like Lyme disease, sinus infections and migraines.

“We have an old saying in medicine: when you hear hoof beats, you don’t think zebras — you think horses,” he said.

Lots of Anecdotes, little Evidence

The natural gas industry says there’s no evidence the drilling is causing health problems.

Public health experts say the only way anyone is going to really know whether the drilling is making people sick is to do some big studies.

“There’s a lot of anecdotal evidence out there. and so a well-conducted study looking at a number of communities could help us better understand if there’s an impact, what its magnitude [is], how we should avoid having that impact if there is one,” said Christopher J. Portier, director of the National Center for Environmental Health and the Agency for Toxic Substances and Disease Registry.

In the meantime, patients and doctors don’t have a lot of options. in western Pennsylvania, a lot of them are referred to Charles Werntz at West Virginia University. Werntz, an occupational medicine specialist, is used to dealing with chemical exposures. Lately, he’s seeing more people who live near the drilling.

But for now, he says he can’t really do much more than offer basic advice: Drink bottled water, air out the house, leave your shoes outside. If it’s still too bad, move — if possible.

“It is frustrating. as a physician, I like it when somebody can come to me with a problem and I can help them solve the problem. Whether it’s through a specific treatment or, you know, whatever. and this is frustrating, because in this case, the treatment is to get away from the exposure. and that’s hard to do,” Werntz said.

Back at Cornerstone, Rinehart just wants to get back to taking care of patients.

“We are in the business of trying to improve and maintain the public’s health here. and now we are in the throes of it. and we’re trying not to point fingers,” Rinehart said.

The next day, people got sick again, and the clinic had to be evacuated once more. so they’ve moved the clinic to temporary offices until someone figures out what’s going on.

Wednesday on Morning Edition, NPR’s Jon Hamilton will report on researchers who think they have a good shot at answering whether drilling is making people sick.

The audio version of this story was produced by Rebecca Davis.