WAI'ANAE — Children at Leihoku Elementary School spent much of yesterday in lockdown as firefighters conducted contamination tests after several youngsters complained of nosebleeds and eye and throat problems from an unknown irritant blown in the wind.

Sixteen fifth- and sixth-graders and one adult were taken to Wai'anae Coast Comprehensive Health Center where they were treated for various health concerns and released, said Honolulu Fire Department Capt. Kenison Tejada.

Three children were treated for nosebleeds, fire officials said.

Firefighters responded to a 9:57 a.m. call from the school and found two children with blood "trickles" coming from their nose and one with a "bloody" nose, Tejada said. Nine others complained of irritation to the eyes, nose and throat.

Firefighters performed seven different tests in and around a classroom in a portable building but were unable to identify a contaminant.

"We don't know at this time what the product was," Tejada said, noting that some of those affected said they detected an odor while others did not.

The children who first complained were in one wing of a double portable building near the entrance to campus. The campus was quickly locked down in an effort to prevent the irritant from spreading, Tejada said. Scores of children then complained about related health concerns and 140 of the youngsters were moved to the cafeteria for monitoring.

About 750 pupils are enrolled at the school, 86-285 Leihoku St.

Twelve pupils in the portable building were sent to the health center. Four pupils who had been elsewhere on the campus and one adult were also taken to the center.

"The health and safety of our students and staff is our utmost priority," principal Randall Miura said.

What happened yesterday frightened some children and rankled a few parents.

Fifth-grader Lisette Castro, 10, said she became dizzy and had a headache shortly after a "big dust of wind" blew through her writing workshop class in the portable classroom. Lisette was among the children taken by ambulance to the health center.

"They put us all in a room and we had to take Tylenol and check our blood pressure and all that," she said from her home, directly across the street from the school. She said she was feeling better and would probably return to school today.

Her mother, Mei Castro, is now worried about what might have made her daughter ill.

Noting that dust from an on-campus construction site often blows into her yard, Castro said: "I don't blame the construction or the school."

She then said: "But why's she getting sick all of a sudden? Oh, yeah, I'm worried. Something is in the air."

After the lockdown was in place, on-campus construction was halted yesterday.

Reach Peter Boylan at pboylan@honoluluadvertiser.com and Will Hoover at whoover@honoluluadvertiser.com.