Posted on: Monday, May 16, 2005

Studies unclear on vog's effects

Associated Press

VOLCANO, Hawai'i — Kilauea volcano, one of the state's most popular tourist attractions, is also, by far, its worst air polluter.

Since the volcano began erupting on Jan. 3, 1983, it has been sending 1,000 metric tons of sulfur dioxide into the atmosphere on an average day, according to the Hawai'i chapter of the American Lung Association.

This is 6,000 times greater than the amount emitted by a major industrial polluter on the Mainland, making Kilauea the nation's top producer of sulfur dioxide.

The sulfur dioxide from Kilauea reacts with other chemicals in the air to form the hazy, naturally-occurring type of air pollution known as "vog," or volcanic smog.

The earliest mentions of vog in the press were in 1950. Most mentioned eye irritation and allergy-like symptoms, but generally implied the condition was benign.

Yet, by the 1980s, Hawai'i had the highest asthma death rate in the country, the Journal of Allergy and Clinical Immunology said.

What are the health risks of ongoing exposure to vog?

Although research teams have conducted a number of studies over the past two decades, definitive conclusions on vog dangers have yet to emerge.

Even without extensive scientific data, Big Island residents have long suspected that vog exposure is dangerous. During "bad air days," schools routinely keep sensitive students indoors and sometimes cancel outdoor events.

The U.S. Geological Service and the National Park Service have developed a sulfur dioxide monitoring plan to alert visitors and workers near the Kilauea caldera in Volcanoes National Park.

A 1995 vog symposium report issued by the state Department of Health said: "State and federal ambient air quality standards are not being exceeded in Kona or other areas of the Big Island, even under the worst conditions.

"Nevertheless, sulfur dioxide, fine particles in the air such as sulfates and acid aerosols, may individually or in combination present significant risk."

In another study, published in 1996, a team led by emergency medicine physician Dr. Fred Holschuh, a current Hawai'i County councilman, looked at the number of Big Island emergency room visits with increased levels of vog between 1981 and 1991.

Holschuh and his colleagues concluded that those living in high vog exposure areas sought treatment for asthma and chronic obstructive pulmonary disease at emergency rooms more often when vog levels were high.

Two in-progress studies also are looking at the issue.

Oregon State University researchers measured vog levels downwind of Kilauea during a three-week period in August 2003. Lead author Bernadette Longo said elevated sulfur dioxide levels can cause bronchial irritation and trigger asthma attacks in vulnerable individuals.

"When Kilauea began erupting in 1983, there were a number of studies that looked at emissions directly from the volcano, but they haven't looked at the dispersal pattern, or the long-term health risk," she said, adding, "What we found is some cause for concern."

The first part of the study was published in the March issue of the journal Geology.

But to date there has been little hard scientific evidence that vog is a primary cause of respiratory problems on the Big Island.

Dr. Elizabeth Tam, a pulmonologist at the University of Hawai'i's John A. Burns School of Medicine, is conducting a five-year study on the possibility of a direct link.

Since 2002, community research teams have been taking biweekly air quality measurements at four to five locations throughout the island. They also are monitoring about 2,000 Big Island elementary school students over a four-year period.

"Sulfur dioxide levels are highest in Ka'u, with particulate matter and acidity highest in South Kona — but they do not rival the amounts in any steel town in Pennsylvania, or in traffic on the San Diego Freeway," Tam said.

Tam also noted that the greatest percentage of children diagnosed with asthma live on the Hamakua Coast, a part of the island with the least vog.

She said high levels of mold and pollen may add to the prevalence of asthma, but she also said the higher level of smoking in the area is a contributing factor.

Tam said the American Lung Association recommends people stay indoors during periods of heavy vog, and because vog levels tend to be higher in the afternoons, it advises people to save outdoor activities for the morning.