COURTESY USGS HAWAIIAN VOLCANO OBSERVATORY
Strong tradewinds fanned the gas-and-ash plume from Halemaumau Crater in this early morning photo taken Monday from the Steaming Bluff overlook.
Gas readings at elevated level for Pahala
Crater emissions were reported for a period of three days in March
HILO » The town of Pahala, 50 miles southwest of Hilo, experienced slightly elevated levels of sulfur dioxide gas from Halemaumau Crater during three days in March, according to data from the state Department of Health.
The method of reporting, a single number giving a 24-hour average, tends to downplay the worst of the gas, but Marya Schwabe, living in Wood Valley near Pahala, had no doubt about its unpleasant effects.
"It really was difficult to breathe," she said. For six to eight hours it was really intense, like smog in a city, she said. But she added, "It wasn't all day."
Federal law requires the state to publish the number if the 24-hour average goes over 0.140 parts per million. On Sunday the reading was 0.181 ppm, followed by 0.154 ppm on Monday. The level also hit 0.149 ppm on March 19.
Different standards for different time periods confuse the picture.
In February, Hawaii Volcanoes National Park planned to let people drive through areas with 1 part per million, but had to close part of Crater Rim Drive when drivers stopped too long.
This week, Hawaii County put out a brochure with danger levels expressed in a color code from green (minimal) to purple (possible evacuation). No numbers were included, but the brochure says sensitive people may be affected by even traces of the gas.
Evacuation is not required at the levels experienced in Pahala, the Health Department said. In fact, the advice is to stay indoors and drink liquids.