Kahuku High & Intermediate School will remain closed again today after a possible pesticide contamination last week and complaints of mild discomfort by some adults who visited the affected area of the campus yesterday.

The school has been closed since Thursday, when an apparent pesticide odor sickened 13 students and two teachers.

Classes had been expected to resume yesterday. School officials will use the additional day for final cleaning and to make sure the school is safe and ready when students and teachers return tomorrow, the state Department of Education said in a press release.

The state Department of Health has conducted tests and declared the campus to be free of contaminants, the DOE said.

However, yesterday some adults experienced mild discomfort, primarily throat constriction, when they were in the upper part of the campus where the worst effects were noted last week, the DOE said.

The Department of Agriculture initiated an investigation Friday and was looking into whether the odor came from a turf farmer nearby who was testing a pesticide on his crop.

Samples were taken to determine if residue in the classrooms is that pesticide, but the results won't be known for two to three weeks, said Robert Boesch, the Agriculture Department's pesticide program manager.

Boesch said yesterday that the farmer had stated that he was using the pesticide for the first time, because of a problem with aphids.

He said that when he was at the school Friday he was unable to detect the chemical odor in the classroom that the school said was most affected.

But Boesch said his skin reacted when he was near the tank that held the farmer's pesticide.

Reach Eloise Aguiar at eaguiar@honoluluadvertiser.com.