广州某工业区大气中PCDD/Fs含量水平及其季节性变化特征

Seasonal Variation of Concentrations and Distribution Characteristics of PCDD/Fs in Atmosphere of an Industrial Area,Guangzhou

通过对广州某工业区大气中2，3，7，8-PCDD／Fs的季节性监测，并对大气中PCDD／Fs的浓度与季节性变化进行了分析．结果表明，该工业区大气中PCDD／Fs的浓度范围为2．33～75．4Pg·m-3，平均值为23．2Pg·m-3，毒性当量浓度I-TEQ范围为0．229-10．7Pg·m-3，平均值为2．00Pg·m-3，高于日本环境空气质量标准推荐年均值0．6Pg·m-3．该工业区PCDD／Fs浓度季节性变化明显，最高的季节为春季（37．8Pg·m-3），浓度最低的季节为夏季（13．5Pg·m。），其次为秋季（22．3Pg·m-3）和冬季（19．1Pg·m-3）；毒性当量浓度变化高低顺序为：春季（5．58Pg·m。）〉夏季（1．06Pg·m-3）〉秋季（0．839Pg·m-3）〉冬季（0．525Pg·m-3）．降雨、季风的季节性变化可能是引起大气中PCDD／Fs浓度季节性变化的原因．

Atmospheric concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDD/Fs） were measured seasonally in an industrial area of Guangzhou City. And seasonal variation of eoneentrations and distribution characteristics of 2,3,7,8- PCDD/Fs was investigated. The PCDD/Fs concentrations and corresponding I-TEQ （toxic equivalent quantity） values were in the range of 2. 33-75.4 pg·m-3 （mean =23.2 pg·m-3） and 0.229-10.7 pg·m-3 （mean =2.00 pg·m-3）, respectively. The seasonal variation of PCDD/Fs concentrations was obvious, with the highest concentration was found in spring （37.8 pg·m-3） and the lowest in summer （13.5 pg· m-3）. However, no obvious difference of concentrations was observed for autumn （22. 3 pg·m-3） and winter （ 19. 1 pg·m-3 ）. The seasonal variation of I-TEQ values is as follows： spring （5.58 pg·m -3 ） 〉 summer （ 1.06 pg·m-3 ） 〉 autumn （0. 839 pg·m-3） 〉 winter （0. 525 pg·m-3 ）. The influences of monsoon and rainfall on the concentration of PCDD/Fs in atmosphere are discussed.