G.R. No. 179441 - St. James College of Paranaque vs. Equitable PCI Bank

Petitioners seek a writ of mandamus directing the LTFRB and DOTC to require public utility vehicles (PUVs) to use compressed natural gas (CNG).
They cite studies (Metro Manila Transportation and Traffic Situation Study 1996; EMB-NCR; Asian Development Bank; Manila Observatory; DENR) on high growth in vehicle ownership and concomitant emissions.

Particulate Matter (PM): adverse effects on respiratory health, productivity, infrastructure, and vegetation.
Carbon Monoxide (CO): disrupts oxygen uptake, harms nervous and cardiovascular systems.
Secondary pollutants: smog from NOx and hydrocarbons; acid rain from SO₂; nitric acid and nitrates formation; plant damage.
Economic costs (Philippine Environment Monitor 2002):

Premature deaths, chronic bronchitis, respiratory symptoms valued over US$430 million.
Increased health incidents in Metro Manila, Davao, Cebu, and Baguio.

CNG composition and advantages: mostly methane, negligible sulfur dioxide, up to 90% less CO, 50% less NOx, 60% less PM.
Drawback: higher methane emissions linked to global warming.

Petitioners invoke Section 16, Article II (right to a balanced and healthful ecology), Oposa v. Factoran, and Section 4, RA 8749 (“Clean Air Act”) to establish duty.
DOTC impleaded; Solicitor General argues mandamus improper—no ministerial duty, law does not mandate CNG, remit to DENR/DOE for fuel standards.
Petitioners reply: LTFRB and DOTC empowered under Sections 2 and 21 of RA 8749 to regulate motor vehicles and implement air quality policies; no other adequate remedy.