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The Honolulu Advertiser
Posted on: Sunday, August 3, 2003

Health impact of 'vog' studied

By Christie Wilson
Neighbor Island Editor

Kilauea is Hawai'i's biggest polluter, spewing out 6,000 times the daily amount of poisonous sulfur dioxide required to qualify as a major industrial source of pollution.

But when it comes to volcanic hazards, destructive lava flows and earthquakes are the most feared public concerns. These events, although spectacular in nature, last a relatively short time and result in clearly defined damage.

Often overlooked are the effects of toxic gases and ash that are continually released from active volcanoes.

"A little bit of volcanic fume may not seem like such a bad thing, but if it hits your house every day most days of the year, it can become a chronic problem," said Jeff Sutton of the Hawaiian Volcano Observatory at Hawai'i Volcanoes National Park on the Big Island. "If we think about Kilauea the way we think about a power plant on the U.S. Mainland, it clearly violates EPA clean-air standards."

Sutton said emissions from Kilauea, which has been continually erupting since 1983, have been linked to acid rain that has damaged crops and property and contributed to the leaching of lead into household water supplies. Fumes from the volcano are even thought to have played a role in drought conditions in Ka'u by preventing the formation of raindrops.

Research into the health effects of volcanic emissions is an emerging field. The International Volcanic Health Hazard Network was formed this year and includes scientists in the fields of volcanology, epidemiology, toxicology, public health and physical chemistry.

One of those scientists is Dr. Jean-Pierre Michaud, a toxicologist and associate professor of chemistry at the University of Hawai'i-Hilo, who is conducting a five-year, $600,000 study on vog — the term for volcanic smog — and acute changes in lung function.

Vog is formed when sulfur dioxide gas reacts chemically with sunlight, oxygen, dust particles and water. Sulfur dioxide irritates the skin and the tissues and mucous membranes of the eyes, nose and throat. During even moderate physical activity, it can penetrate deep into the airway and produce respiratory distress in certain individuals, according to the Hawaiian Volcano Observatory. Michaud said several deaths have occurred from exposure to the fumes at Hawai'i Volcanoes National Park, home to Kilauea.

Michaud said not very many scientists have been looking at the link between volcanoes and health, and much of the research that is being done is focusing on the effects of volcanic ash, first recognized in the wake of the explosive Mount St. Helens eruption in 1980.

"Most of the volcanoes worldwide have ash emissions in abundance," Michaud said. Kilauea puts out very little ash, he said, while emitting 2,000 tons of toxic sulfur dioxide gas a day. "Luckily most of it blows out to sea," he said.

Michaud's study, paid for by the Centers for Disease Control and Prevention, is looking at the acute, or immediate, effects of vog episodes. The participants have included schoolchildren in Hilo and Mountain View, near the volcano, and adults who work within the national park, including park and Hawaiian Volcano Observatory staff and workers at Kilauea Military Camp.

Using electronic lung function meters, the study's subjects were told to blow into the devices three times in the morning and again in the evening. The meters automatically record the peak air flow and provide an indication of whether the airway is constricted from irritants or other causes.

Michaud said he was told by other researchers it would be difficult to get the subjects to cooperate beyond two or three weeks, but he was able to maintain the monitoring over two- to three-month periods. The most recent monitoring session was conducted earlier this year, and the final session, using adults from the national park, will occur in the fall.

The study is subject to natural conditions, and Michaud said the lack of severe vog episodes during the monitoring periods has been frustrating.

"So far we haven't seen huge effects, but we haven't had the biggest vog events," he said.

He does report that he has seen some relationship between emergency room visits for respiratory problems and higher vog levels. Michaud said researchers also are learning there are many other factors in lung function that haven't been getting proper attention on the Big Island, namely "bioaerosols" such as cockroach dander, pollen, dust mites and mold.

Another question is whether short-term vog episodes over a long time contribute to chronic health problems such as asthma.

"One has to wonder about children growing up in this environment," said Michaud, who is a co-investigator in a separate five-year study of the long-term effects of volcanic emissions.

Approximately 1,700 fourth- and fifth-graders in Kona are participating in the $1.5 million study, paid for by the National Institute of Environmental Health Sciences.

In March, principal investigator Dr. Elizabeth Tam of the University of Hawai'i's John A. Burns School of Medicine released preliminary data showing that 22 percent of children interviewed for the study indicated they had been diagnosed with asthma. That compares with an asthma rate of about 13 percent statewide and nationally.

Tam reported the study also found high asthma rates throughout the Big Island, even in areas that are not prone to vog. That suggests the influence of other factors such as those mentioned by Michaud.

Since the Kilauea emissions cannot be controlled, new knowledge about the extent of the hazard could lead to more explicit public health precautions, Michaud said. It also would provide "informed consent" to visitors and people planning to move to the Big Island who may be concerned about vog, he said.

"It will help us get a better understanding of how sensitive people can be to this," he said.

Reach Christie Wilson at cwilson@honoluluadvertiser.com or at (808) 244-4880.