Engr. Alan Arranguez, EM-7 chief, said stationary sources or industries like power stations, cement plants, and oil refineries are the major contributors of sulfur oxide to the air, and the bureau's monitoring of air quality has ranked the various places in Cebu that contribute the most to air pollution.
Naga, being the host of 15 industries such as cement plants, coal plants, and mining, was found the biggest contributor of sulfur oxide to the air with 4,018 tons of SO2 per year.
Mandaue City, which has the most number of industrial firms with 226, only ranked second emitting 1,243 tons of SO2 per year. Lapu-Lapu City, which has 145 industries, only produced 855.7 tons of SO2 per year.
Cebu City, as host to 48 industries, came in fourth with 722.9 tons of SO2 per year, followed by Liloan town with 19.09 tons of SO2 per year from its seven industrial firms.
Mobile sources like cars, PUJs, buses, pick-ups, trucks, and tricycles also contribute large amount of SO2 to the air with a total of 1,002.59 tons per year.
Arranquez said that aside from these two sorts of sources of pollutants, households also played a critical role in air pollution.
Cebu City, with a total of 718,821 households, tops in this regard contributing 20.13 tons of SO2 to the air per year. Talisay City, with 148,110 households, produced 13.03 tons of SO2 per year, followed by Mandaue City emitting 7.30 tons of SO2 per year from its 259,728 households.
Arranguez said his office has been undertaking a constant monitoring of Cebu's air quality and the DENR has prohibited the burning of garbage and other materials that contribute to air pollution.
However, EMB-7 pollution control head Engr. Marcelino Tabuco said the figures have not yet reached the critical stage, specifically on SO2 and nitrogen oxide emissions.
He said that the average SO2 and NO2 emissions for industries is 1500 microgram per normal cubic meter while the normal suspended particulate matter is 90 microgram per normal cubic meter.
All industries in Cebu have, so far, met the emission standards that the DENR had set, Tabuco said but urged residents to report any observations of pollutants emitted by any industrial firms. - Wenna A. Berondo