Honokaa Elementary and Honokaa High and Intermediate schools closed early today after a “strong chemical odor” sent 40 students and 10 adults from the high school to nearby medical centers, according to the Department of Education.

Those affected reported symptoms including nausea, dizziness and respiratory problems. There were no reports of medical issues at Honokaa Elementary, which is located across the street from the high school.

According to hazardous materials investigators, the odor was traced to a nearby resident who was using a mix of chemicals to spray his yard. Honokaa is located near Waimea on the Big Island.

It’s the fifth such incident to affect Hawaii public schools over the past year. Overall, eight Hawaii public schools schools have had to evacuate students because of chemical odor outbreaks since November. The other six schools are on Oahu.

The most recent incident was in April, when 25 students and two adults at Kahaluu Elementary were sent to the hospital after reporting similar symptoms.

Another incident happened in early March at Manoa’s Noelani Elementary School. Before that, it was Hawaii Kai’s Kamiloiki Elementary School and Ewa Beach’s Kaimiloa Elementary, Pohakea Elementary and Campbell High schools in late November.

The Honokaa schools resume classes tomorrow. Honokaa Elementary enrolls about 360 students, while roughly 600 students attend the high and intermediate school.