HONOLULU -- While two major brush fires on the Big Island have consumed nearly 30,000 acres in South Kohala, another problem has arisen: possible respiratory dangers.

Big Island firefighters spent another full day battling the brush fires. Hawaii County Civil Defense said the fire in Waikoloa is about 80 percent contained. It has already charred more than 25,000 acres.

The fires posed no threat to any homes Thursday. However, officials said the brush fires have caused a secondary problem. Strong winds up to 20 mph are picking up ash and dust, causing a possible health hazard.

The Department of Health will be sending a Clean Air Branch specialist to assess the situation on Friday.

Officials say residents with respiratory problems should stay indoors.

Officials opened all roads, highways and Waikoloa Elementary School Thursday.

Akoni Pule Highway also reopened after being closed overnight while firefighters fought back the flames. That fire has blackened about 2,500 acres.