“…Major anthropogenic sources of atmospheric SO 2 include power plants that burn high-sulfur coal, paper and pulp industries, petroleum refineries, industrial processes for roasting of nonmetallic ores, and incineration of solid waste-particularly of hazardous and medical wastes. 4,5 At present, many techniques, such as differential optical absorption spectroscopy ͑DOAS͒, 6,7 correlation spectroscopy ͑COSPEC͒, 8,9 differential absorption lidar ͑DIAL͒, [10][11][12] and tunable diode laser absorption spectroscopy ͑TDLAS͒ techniques 13 are used for monitoring SO 2 in air.…”