HILO, Hawai'i — Big Island residents shouldn't wait for official evacuation warnings before trying to escape toxic volcanic fumes.

Hawai'i County Civil Defense Director Quince Mento says he's aware that the sulfur dioxide alert system is inadequate and slow.

Mento says people should get indoors, close windows or evacuate the area if they see volcanic gases approaching.

One problem of alerting people about worsening air quality is that the island's winds often blow the fumes away before they receive the warning.

Mento says Hilo residents experience health problems by the time officials recognize the severity of the sulfur dioxide in the air.

He says vog is hard to predict, and it dissipates by the time it's noticed.