Dr. Jess Canto, director of the Region 1 Medical Center in Dagupan City, said laboratory tests showed that the food served at the canteen of the Great Plebeian College had nitrate which the cook could have mistaken for salt.
Canto said excessive intake of nitrate could cause abdominal pain.
The victims suffered vomiting, dizziness and headaches and were rushed to the Western Pangasinan District Hospital here.