A mysterious irritant causing blisters and rashes sent up to 91 West Covina students to hospitals for treatment Monday and prompted officials to close a school playing field.
None of the students from Rincon Intermediate School, who were stricken during morning physical education classes, were seriously injured and all but one had been treated and released by late afternoon, according to a spokeswoman for Rowland Unified School District. Hospital officials said the rashes disappeared after the affected areas were bathed.
Fire, police, health and agriculture officials were at a loss to explain the source of the problem. The symptoms were at first blamed on pesticides, but school officials said the field had not been sprayed.
A second possible irritant--harmful weeds--was also ruled out after an agriculture inspector found no such plants on the school grounds.
"We really don't know much yet," said Coto Fiksdal, deputy county agricultural commissioner. "We are going to take samples of soils and leaves but nothing appears out of the ordinary."
The 900 students at the school will be kept off the field until the problem is identified or officials determine it is safe, district spokeswoman Diane Ho said.
The first symptoms were detected before 10 a.m., during a physical education class, when a handful of students complained of itching, which quickly spread and developed into blisters on the most-seriously affected children, West Covina Police Lt. Ross Heaton said. Some of the children also complained of breathing difficulties.
Because the reaction was unfamiliar to the school nurse, county paramedics were called, Ho said. By the time they arrived, students from two other physical education classes reported similar symptoms.
The students were taken to six hospitals, but by late afternoon only one was still being treated at Inter-Community Medical Center in Covina for breathing difficulties. That student was also expected to be released, Ho said.
Although the field will be tested for pesticides, the irritant was likely not man-made, Fiksdal said.
"There are weeds that are irritating, but the inspector walked the entire field and didn't find anything but average athletic field-type stuff," Fiksdal said. "Some plants can go through stages and over the weekend could bloom, but since we didn't see anything unusual, it doesn't seem likely."