Volcanic emissions down, West Hawaii skies clearest in years

KAILUA-KONA — Take a deep breath.

A pall of seemingly unrelenting vog swallowed West Hawaii for months as Kilauea wreaked havoc in Puna. Since the volcano has cooled, the excess pollution subsided. But the changes are actually more significant than that.

“In Kona, it seems like (air quality) looks better than it was prior to the eruption,” said Lisa Young, environmental health specialist with the state Department of Health’s Clean Air Branch.

Young’s statement was a soft determination that she explained is based more on anecdotal evidence and what she’s heard from people throughout West Hawaii rather than on a hard comparison of pre- and post-eruption pollution numbers.

However, there are scientific indicators that back up what Young believes to be true — that the air is as clean as it’s been in recent memory.

When it comes to air quality, green is good. Literally. Particulate matter is registered by monitors across the island and posted on airnow.gov, an air quality website run by the U.S. Environmental Protection Agency. The state DOH’s short-term SO2 advisory website uses the same color-coding system at hiso2index.info.

A green dot indicates “good” air quality on both sites. And for weeks, Kailua-Kona and surrounding areas up and down the coast have been in the green.

Before the eruption that began in May, Young said West Hawaii areas were subject to yellow days, indicating “moderate” air quality. During the eruption, air quality levels frequently hit orange and red, which signify “unhealthy for sensitive groups” and plain old “unhealthy,” respectively.

“We got green everywhere,” Young said. “It’s been really good.”

More than monitors, hard data from the volcano itself offers explanation for the perpetually clear Kona skies over the last few weeks.

Before the most recent eruption, Kilauea was spewing about 5,000 tons of sulfur dioxide (SO2) per day. Save for a few hundred tons, all of those emissions originated at the summit, said Patricia Nadeau, research geologist and part of the gas geochemistry team at the Hawaiian Volcano Observatory.

During the ash explosions in the middle of May, summit emissions peaked at about 10,000 tons per day but dropped to a few hundred tons around a month later, Nadeau added.

However, Lower East Rift Zone emissions, which had been tallied at only a few hundred tons daily prior to the May eruption, soared in early August to over 50,000 tons every 24 hours.

“SO2 emissions generally track closely with the presence and amount of lava at or near the surface,” Nadeau said. “Emissions were relatively high when there was a lava lake present at the summit before this recent eruption, and then very high during the voluminous fissure eruptions of the Lower East Rift. Kilauea is still an active volcano, but has little to no lava at the surface, which correlates to very low SO2 emissions.”

At this point, all three sites of volcanic emissions on Kilauea are producing a combined SO2 emissions load of less than 1,000 tons per day — the lowest totals in more than a decade.

But the volcano is fickle, and no one knows how long current conditions might last. So in Kona, residents and businesses alike are making the most of them.

“It’s completely changed how I live when I’m here,” said Lindsey Jorgensen, a frequent visitor who was last on the island in June.

She said she’s out going for walks or hiking or on the water far more frequently this time around, as before the vog disrupted her breathing and stung her eyes too much for comfort.

Mara Masuda, assistant general manager for Huggo’s and Huggo’s On the Rocks, which are both open-air venues, said business always dips in the summer months so quantifying the vog’s precise impact is a difficult task. However, there were changes she noticed.

“I think it was more our local patrons that it seemed to kind of affect,” explained Masuda, adding that regulars who were more sensitive to changes in air quality, likely because they’re more familiar with the island, stopped showing up as frequently.

They’re all back now, she said, but some departures were more permanent.

“I had a few employees that actually moved because they were having issues,” Masuda said.

Back when it was hard to see through the vog to clearer skies ahead, West Hawaii residents were frustrated with a lack of monitoring on the leeward side of the island. In response, the DOH planned to add several new vog monitors. That’s still the plan today.

The department has added two SO2 monitors, one each in Pahoa and Keaau. Only one SO2 monitor is located on the leeward side, which is in Kona. However, SO2 in it’s normal form isn’t the main issue for West Hawaii. The SO2 monitor read green on several heavy vog days during the eruption.

The greater concern is particulate matter (PM), the stuff that was producing unhealthy orange and red days all across West Hawaii over the last several months. The department has added four PM monitors at sites in Waikoloa, Kona, Honaunau and Naalehu, all of which will be permanent, Young said.

And more are coming.

“We’re not going to wait until something happens,” Young added. “We’re just going to put them up so they’ll be there instead of like last time.”