When the Kilauea volcano on Hawaii’s Big Island erupted in 2018 it destroyed around 700 homes, displaced 2,500 residents, and spewed dangerous gas and ash into the air.

But a team from Princeton led by Mark Zondlo, an associate professor of civil and environmental engineering, was on hand to assess conditions and monitor the levels of these dangerous gases. They used special sensors mounted atop cars to detect the levels of specific gases, such as carbon dioxide, sulfur dioxide, methane, ammonia and other pollutants. The mobile nature of these sensors allowed the researchers to monitor large stretches and specific locations on the island in “real time.”

These data were used to complement the data generated from satellites and ground monitoring stations to create a more precise picture of the potential danger.

“Volcano emissions are lofted into the atmosphere,” said Zondlo, “so the plume [of volcanic gas] could be lofted well above the surface, and the air quality could be perfectly fine at the surface. That’s why we need surface networks.”

The team’s data and analyses are designed to help public health officials and scientists better understand how volcanoes influence air quality and how changes in air quality might be associated with health effects.