AIR pollution worsened last month compared to the same period last year, reflecting a general long-term decline in air quality around the territory. Levels of health-debilitating sulphur dioxide, nitrogen dioxide and suspended particulates all increased slightly from last year in February, the Environmental Protection Department (EPD) reported yesterday. Principal Environmental Protection Officer, Mr Raymond Leung Pak-ming, said the precise reason had not been pinned down. ''In general, over the last three years, we have had a steady worsening of air quality,'' he said. ''It could be due to increased emissions from local industry or from vehicles, because the number of vehicles is increasing, or it might be because of increased industrial activity over the border.''