Normal rain is slightly acidic, with a pH of 5.6, while acid rain generally has a pH between 4.2 and 4.4. Rotting vegetation and erupting volcanoes release some chemicals that can cause acid rain ...

MANILA, Philippines — Acid rain can occur following the volcanic smog or vog from Taal volcano, Department of Science and Technology (DOST) Secretary Renato Solidum said on Friday.

The sulfur dioxide level at the Philippines' Taal Volcano has increased, causing constant volcanic smog and the possibility of acid rain, the country's Science and Technology Ministry said on Friday.