The Variety of SO2、NO2 ,Air Pollutants Concentration of Nanchong City in Recent 16 Years

Based on air monitoring data during 1996-2011 in Nanchong city,analysis of atmospheric SO2、NO2 annual variation characteristics and laws, and quality evaluation. The results show that: the concentration of SO2 decreased, and the small fluctuations in the range of SO2 concentrations in recent 16 years of Nanchong City. Annual average of mass concentration of SO2 more than 0.1 mg / m3 in 1996-2000, and not more than second level of "ambient air quality standard" GB3095-2012 in 2001-1011.The concentration of NO2 fluctuated between 0.034 mg / m3 and 0.056 mg / m3 in 1996-2001, and are less than 0.040 mg / m3 2002-2011.In the all, pollution of SO2、NO2 are reduced significantly through the treatment.