PAHALA, Hawai'i — Big Island residents take pride in their ability to tolerate and adapt to the elements. It isn't unusual in a single year for residents to put up with drought, long days of rain that can cause flooding, or threats from wildfires.

Even so, the recent days of heavy volcanic emissions and light kona winds have been obnoxious and in some cases damaging, and have some residents worrying about the future.

The morning sun was a distant red spot in a sea of gray vog in Hilo late last week. Teachers at some Big Island schools advised students to take recess indoors, and some elderly pedestrians walked through downtown Hilo with a handkerchief clamped over nose and mouth.

State and county officials say there hasn't been an increase in emergency medical calls because of respiratory problems or unusual numbers of emergency room visits in Hilo or Kona, but small Ka'u Hospital in Pahala has seen an estimated 50 percent increase in emergency room and clinic visits from people complaining of respiratory problems, said hospital administrator Merilyn Harris.

Pahala and the rest of Ka'u have received the brunt of the increased emissions from Kilauea since the volcano burst open a new vent at Halema'uma'u on March 12, which vastly increased the gases released at the summit.

So far the trade winds have blown most of the fumes to the southwest, and federal ambient air quality standards for average 24-hour sulfur dioxide exposure were exceeded nine times in the past six weeks in Pahala, according to the state Department of Health.

Kona, the island's tourism hub, has suffered from thick vog or volcanic haze.

On April 15 and April 16, monitoring equipment at Konawaena High School detected particulate matter from the vog that exceeded National Ambient Air Quality Standards there for the first time since continuous monitoring began in March.

When the winds shift to blow from the southeast or southwest, conditions tend to improve in Kona and Ka'u, but quickly deteriorate in Volcano Village, Puna and Hilo.

Federal officials closed Hawai'i Volcanoes National Park twice this month because of concern that sulfur dioxide levels there were unsafe, evacuating about 2,000 people from research facilities, campgrounds and the Volcano House hotel along with popular tourist spots. The park reopened Friday.

HEADACHE ALL AROUND

All of this has played out in April, a month when Hawai'i usually enjoys trade winds that blow volcanic emissions away from the more populated areas of Puna and Hilo. But kona winds from the southwest are inevitable, and will be increasingly uncomfortable with Halema'uma'u adding sulfur dioxide to the emissions already being produced by Pu'u 'O'o.

"Because this is going to be a long-term thing, it seems like the public is adjusting, tolerating, making their own personal life changes to minimize the risk, whether it be either staying indoors or leaving the area," said Big Island Fire Chief Darryl Oliveira.

Ka'u real estate broker Patti Barry said her granddaughter has been living with her for four years, but Barry is considering sending the girl to Maui to spend her senior year with her mother because the 16-year-old has mild asthma. She is a swimmer and likes to walk two miles a day, but Barry has been keeping her indoors for the past couple of weeks.

The girl has suffered from headaches, and "it's starting to cause a problem," Barry said. "I don't know what the doctors are saying about it, but I don't think our kids can handle this for long periods of time. I don't know what we're going to do.

"If it comes to summer and things change, we've got a couple of months to make that decision. I'd like her to graduate out here at Ka'u."

The vog and volcanic fumes also have been a business issue, Barry said.

"I'm having a very hard time holding my deals together," Barry said. "I have to give a report almost every two days as to what's happening, because it's on CNN News and they're all picking it up through the news. It's whatever the news media puts out there is making our clients nervous."

Barry said she hopes the media will remind people that the trade winds blow frequently, directing the vog out to sea.

CALCULATING THE RISKS

Lt. Col. Trey Johnson, commander of the 93rd Civil Support Team of the Hawai'i National Guard, has been studying the volcanic plumes from Halema'uma'u and Pu'u 'O'o since March, using a computer model to try to calculate where the different winds will blow sulfur dioxide.

The worst-case scenarios provided by that model involve sustained kona winds from the southwest at about 15 mph, which would likely focus a wedge-shaped band of vog and sulfur dioxide that would cause conditions classified as "purple" or "extreme" in a sizable portion of Upper Puna, and along the Lower Puna coast from the southern edge of Hawaiian Paradise Park to Kea'au, he said.

Purple conditions mean sulfur dioxide levels exceed 3 parts per million. Under those conditions, the state Department of Health recommends that all residents avoid outdoor activity, and leave the area if directed to do so by county Civil Defense.

The model also suggests that similar "purple" conditions would be created in a wider swath of Upper Puna and along the coast from Hilo to Kalapana by slower 5 mph winds from the southwest, Johnson said.

The computer model may somewhat overstate the risk at the moment because it assumes that Pu'u 'O'o is producing 2,500 metric tons of sulfur dioxide per day, and that Halema'uma'u is producing 1,200 tons.

In fact, Pu'u 'O'o has recently been producing about 1,700 tons, and Halema'uma'u about 1,000 tons, but those volumes vary from day to day.

Scientists say there is no way to judge how long the emissions may continue at the summit because there are still so many unknowns about Kilauea.

"At this point, because this is really a new type of event, we really don't know," said Don Thomas, director of the Center for the Study of Active Volcanoes at the University of Hawai'i-Hilo.

MIGHT LINGER, MIGHT NOT

One possibility is that the sulfur dioxide at Halema'uma'u is being released by a stagnant pool of magma below the surface, and at some point the emissions will taper off.

Another possibility — perhaps the opposite extreme — is that Halema'uma'u has opened a pipeline to Pu'u 'O'o that allows some of the gases from the magma erupting at the pu'u to escape through a conduit that extends to the summit. That could mean that the summit emissions will continue indefinitely.

Mount Etna on the east coast of Sicily has produced substantial amounts of sulfur dioxide for a long time, and many South and Central American volcanoes go through extended episodes of very large gas releases.

"Yes, it does affect the downwind communities," Thomas said of those volcanoes. "Do they live with it? Yes. Do they live comfortably with it? Probably not.

"We haven't seen the full range of activity for Kilauea, and it may be uncomfortable, and it may be uncomfortable for quite a while."

GRITTY AGRICULTURE

At Aikane Plantation Coffee Co. in Pahala, coffee farmer Phil Becker said a gray film of ash has been covering vehicles and water troughs used by the 60 head of cattle on the property, and sometimes coats the arms of farm workers with a gray film as they brush against the leaves picking coffee.

Becker has lived in Ka'u for more than 50 years and his wife has lived there for generations, and neither has ever seen this much vog or ash before.

"It comes and goes. This morning we could hardly see; it was like being in a cloud," he said. "In the morning we clean the house, and in the afternoon there's a gray film over everything.

"You can feel it, it's a gritty feeling."

The Beckers are hoping the fumes will help the coffee crop, which likes sulfur, but they are already seeing damage to the protea plants they grow and sell. Some plants have been turning brown and dying, while other produce deformed blossoms.

Farther to the southwest, in Hawaiian Ocean View Estates, flower farmer Loren Heck saw extensive damage to his protea plants when sulfur dioxide levels in the area built up on April 16 to the point that Civil Defense advised residents in mauka areas of the subdivision to evacuate.

The evacuation advisory was quickly lifted when the air quality improved, but Heck could almost see the leaves of many of the protea turning brown.

"Within I would say three hours, you could see the plants were being affected by it," he said. "This has never happened before, nothing even comparable to this."

A neighbor lost a lettuce crop worth an estimated $10,000, but Heck could not estimate the value of his losses because he isn't sure how many of the protea plants will finally die.

"It will really cost me if it kills the plants, but I'm not sure it's going to do that," Heck said. "If it kills the plants, well, I won't be in the business."