THE Municipality of Sibalom in Antique has confirmed that pesticide contamination is the likely cause behind the July 2, 2025 foul odor incident at Pis-anan National High School, which resulted in the hospitalization of nearly 250 students.
In an official statement, Sibalom Mayor Gian Carlo Occeña said the conclusion was based on the Initial and Partial Report from Task Force Pis-anan and the Final Toxicological Report from the Toxicology Specialty Center at the Western Visayas Sanitarium and General Hospital (WVSGH).
“According to the report, cypermethrin, a chemical commonly used in pesticides, was detected in multiple indoor and outdoor areas of the school, including classroom walls, doors, and surrounding vegetation. This indicates airborne dispersal of the substance,” Occeña said.
He added that “laboratory testing of two affected students revealed elevated levels of urinary formic acid, suggesting possible exposure to methanol, a known solvent in certain pesticide and fogging formulations.”
Occeña emphasized that “there is sufficient evidence of environmental contamination by cypermethrin within the school premises, most likely due to airborne pesticide drift compounded by weather conditions.”
“The clinical symptoms experienced, the nature of the odor, and the distribution of residues are all consistent with acute exposure to pyrethroid pesticides,” he said, also noting the elevated formic acid levels as “a concern over the possible involvement of methanol-based formulations as contributing factors.”
He clarified that the statement is not yet the final report, as additional environmental sample results are still pending.
“We assure the public that we are treating this matter with the utmost seriousness and urgency. We are committed to ensuring accountability, safeguarding public health, and preventing similar incidents in the future,” Occeña added.
Meanwhile, the Pesticide Action Network Asia Pacific (Panap.net) issued a strong condemnation of the incident from its headquarters in Penang, Malaysia, calling it “deeply alarming and unacceptable.”
“Cypermethrin is a synthetic pyrethroid insecticide classified by Panap as one of the Terrible Twenty — the most toxic pesticides that pose severe threats to children,” Panap said.
“It is known to be acutely toxic, especially to children, and is associated with respiratory distress, neurotoxicity, endocrine disruption, and long-term impacts such as increased risk of breast cancer and male reproductive disorders,” it added.
Panap added that the discovery of pesticide residues in and around a school “meant to be safe for learning is a gross violation of children’s rights and public safety.”
The group pointed to pesticide drift, likely from nearby agricultural spraying, as the primary cause of contamination.
“This tragic incident must serve as a wake-up call,” Panap said.
It reiterated its demand for the Philippine government to ban highly hazardous pesticides (HHPs) like cypermethrin and to identify the manufacturers and sellers involved, such as agrochemical giants BASF and Syngenta.
“We call on all relevant authorities and policymakers to urgently take action, ensure justice and accountability for those affected, and prioritize the protection of children and communities from toxic pesticide exposure,” the group urged.
As an immediate step, Panap renewed its call for the establishment of pesticide-free buffer zones of at least one kilometer around schools and other child-sensitive areas, adding: “Children must never again be placed in harm’s way due to pesticide drift and unsafe agricultural practices.”
The Municipality of Sibalom has formally endorsed all findings to the appropriate authorities and vowed to provide updates as new laboratory results become available. (Leo Solinap/SunStar Philippines)