Hawaii Kilauea Volcano Latest: Acid Rain Could Fall After Eruption

The people on Hawaii's Big Island are evacuating areas where there are high levels of sulfur dioxide leaking out of the lava emitted by the Kilauea volcano. Lava, dangerous gases and earthquakes are all potential risks on the island, but if the weather changes, another risk will be added to that list—acid rain.

"It's reasonably normal for this volcano," Mark Elliot a meteorologist for The Weather Channel, told Newsweek. The Kilauea volcano is known for emitting a lot of sulfur dioxide, he added, though not all volcanoes have the same makeup.

The gas can mix with the oxygen and any water vapor in the air, as well as with sunlight, to form sulfuric acid. "It's an unsafe gas to breathe in too much of," Elliot said, but luckily it's a gas humans detect easily: The smell is similar to that of rotting eggs or fireworks. When water vapor turns into rain and passes through that sulfuric acid in the air, the product is acid rain.

The volcano erupted days ago and has continued to leak gas into the air, making "sulfuric acid in the downwind areas" likely, Elliot said. The forecast for an area where the gas has been leaking, not far from the volcano, included rain for Wednesday through Thursday evening.

Acid rain mainly impacts health, agriculture and the drinking water systems in the area where acid rain falls, Elliot said. Additionally, there are short and long-term effects the rain can have.

In the short term, the gases in the air that cause acid rain have the largest impact on asthma sufferers and those in more high-risk groups, like the elderly. "You're not breathing in as much oxygen as you should be, so it messes with you," Elliot said.

Symptoms can include difficulty breathing and irritation in the throat, lungs or eyes, according to the Hawaii Emergency Management Agency. The longer-term effects of the sulfur dioxide are less well-known but are something researchers are trying to study, Hawaii News Now reported.

The rain also impacts the health of plants: While some are more sensitive than others, acid rain can do significant damage and even kill some plants. "The plants are affected by it pretty substantially in that it is an acid falling onto the plants. It can mess up the leaves. It can get into the root system," Elliot told Newsweek.

Lastly, the rain can contaminate drinking water supplies. The chemicals in acid rain can cause other elements, like lead, to leach from rain-catching materials or out of roofs and plumbing. Residents should be careful about their drinking water because they might not know if it's been contaminated following acid rain.

As long as the volcano continues to release the gas into the air, there's potential for acid rain to fall on the island. As of Wednesday, researchers were unsure when the volcano's activity would die down.

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Ground cracking extends across Highway 130, in Puna, Hawaii, on on May 7. The gases released by the volcanic eruption could cause acid rain on the island. U.S. Geological Survey via Getty Images