The risk of upper respiratory problems increased significantly on the Big Island during high vog events — and children were the most sensitive to the bad air — according to a new study that compared clinic visits in communities hardest hit by volcanic emissions before and after a new Kilauea vent opened in March 2008.

The research is the first to quantify the "real risk" of upper respiratory symptoms associated with the thicker vog on Hawaii island and could help push more state, county and federal help to areas affected by choking vog, said state Sen. Josh Green, an emergency physician and one of the report’s co-investigators.

The study, recently published in the Journal of Toxicology and Environmental Health, compared clinic visits in Pahala, Ocean View and Naalehu 14 weeks before and after the new Kilauea vent opened, doubling the amount of emissions.

It found that during thick vog there was a sixfold increase in the number of people with acute airway problems that required emergency care, up to 300 percent increases in severe sore throats and headaches, and a 56 percent increase in people with coughs.

For the study’s authors — and those who live in the state’s voggiest corridor — the findings are no surprise.

Residents have long been reporting increases in upper respiratory problems, and clinics have often said that they see more patients complaining of cough, sore throats, headaches and watery eyes when the vog gets bad.

But researchers say the study shows the magnitude of the vog’s effects on the population, especially children, who are more susceptible to air pollution.

And they hope the research will trigger more assistance for communities near the volcano.

They also would like to see the research improve public awareness about the risks of vog — and what residents can do to protect themselves, including seeking air conditioning or not exercising during thick vog events.

"The key on all this is to minimize your exposure," said study principal investigator Bernadette Longo, an assistant professor at the University of Nevada-Reno’s Orvis School of Nursing. "If people take the necessary precautions, they can lower the health risks posed by the vog, and ultimately, that is the purpose of our research."

She added that studies on Hawaii island residents downwind of volcanic vents are continuing.

And though the published research shows the risk of acute respiratory symptoms went up when the vog got bad, there is so far no link between volcanic emissions and chronic disease.

Green, who lives on the Big Island and is vice chairman of the Senate Health Committee, said the study should add even more urgency to the state’s response to the vog, and added he would like to see the state Health Department further "fortify" its air monitoring system.

The state has put millions of dollars into helping communities affected by heavy vog, including air conditioning Kau schools, beefing up air monitoring and increasing vog awareness and emergency procedures.

But there is still lots of work to do, Green said.

Kau Hospital, for example, the only emergency room in a region the size of Oahu, still has no central air conditioning system. A project under way to equip the hospital with air conditioning will take years to complete.

Just about every corner of the state has had markedly heavier episodes of vog since March 2008, when the Halemaumau vent started emitting about 2,000 metric tons of sulfur dioxide daily, a number that has since dropped to about 1,000 metric tons of gas daily.

That is in addition to the average 1,000 to 2,000 metric tons a day emitted by Kilauea’s Puu Oo vent, which started up in January 1983. (On Oct. 14, the last time a measurement was conducted at Puu Oo, the vent was emitting about 340 tons a day).

Kau residents say since emissions started decreasing, the number of bad vog days has also dropped.

But the air still gets bad.

This month alone, sulfur dioxide levels in Kau communities exceeded federal air quality standards at least 18 times, according to the state Health Department.

The new study shows children especially are at higher risk of developing a cough and other upper respiratory problems during thick vog. Seniors, smokers and people with existing conditions, such as asthma and emphysema, are also at higher risk.

"The results suggest that children and adolescents are likely to be the most sensitive to sulfur dioxide exposure, which is especially concerning," Longo said.

Merilyn Harris, Kau Hospital administrator, said the good news in the wake of the study is air quality has improved.

"We’ve had haze but it hasn’t been as severe," she said, adding, "Some days are worse than others."

The facility is in the planning and design phase of a $4.7 million project to install central air conditioning and improve ventilation to ensure bad air stays out. (As it is, sulfur dioxide seeps under doors and through jalousie windows during high vog events.)

Harris said the hospital and community groups continue to try to improve education among residents on what they should do when the vog gets bad.

"In many ways, people are getting a little bit more used to it," Harris added. "You kind of acclimatize to it a bit."