There aren't enough air-conditioned shelters for the estimated 12,000 Big Island residents downwind of volcanic fumes spewing out of Halema'uma'u Crater since March, officials said yesterday.

Ka'u High School has designated a temporary safe room, but it's only large enough for its students at highest risk for respiratory problems. Residents are urged to go to the two supermarkets in Ka'u town for air-conditioned relief, or to the beach.

And the Ka'u Hospital has only one room air-conditioned, but it's not scrubbed free of sulfur dioxide for patients sensitive to air pollutants.

Those facts arose during 12 hours of testimony to the House Special Committee on Vog Effects, which is trying to learn how the sulfur dioxide emissions affect people, plants, the economy and water collection systems.

"It's a very difficult, complex task for an ongoing threat," Ed Teixeira, state Civil Defense vice director, said yesterday at the state Capitol. "It's a moving target. We can't work fast enough to keep up with the data."

It will take years to determine the long-term effects of the emissions, but state officials hope to deal with immediate concerns.

"The hardest thing has been to find the right questions to ask," said Rep. Bob Herkes, D-5th (Ka'u, S. Kona). "Our losses are miniscule compared to the Gulf Coast, but we have to deal with it. These are our people."

The next step is to take the information and come up with a plan to deal with the short- and long-term effects from the fumes, said Herkes. A final report will be prepared for the speaker of the state House, he said.

"Normally, we respond after a natural disaster, so our conventional disaster response will not work for volcanic activity," he said.

In March, a new vent opened at Halema'uma'u Crater, spewing volcanic gases into the air and causing health problems. The wind tends to blow southwest in the mornings, away from communities, but it tends to blow upslope by midday, bringing the plume over populated areas.

Short-term reaction to vog may include breathing problems for those with respiratory conditions, itchy eyes and sore throats.

An ongoing study by University of Hawai'i medical professor Elizabeth Tam showed that asthma rates are not correlated with exposure to vog in Big Island children.

The Hawai'i Medical Service Association has studied emergency-room claims from all its 730,000 members. The claims show an increase in the asthma rate, though there's no way to link the increase with incidents of vog, said Jennifer Diesman, assistant vice president of HMSA government relations.

"It's hard to know what the data mean," Diesman said.

At Ka'u Hospital, a 21-bed facility, sometimes the air quality is worse inside the building than outside, said Marilyn Harris, hospital administrator. That's because the hospital has open windows and doors that don't seal. It would cost more than $4.7 million to retrofit the hospital with new windows, doors and air-conditioning, Harris said.

"It's not the safest place to go, and we're not equipped to deal with emergency-room patients. There's a limit of what we can do in our current facility," Harris said. "At one time, we thought one of the gems of Ka'u Hospital was our open windows to bring in the cool breezes."