惠州绿化乔木叶片及其叶面降尘对大气SO_2污染的生物监测

Biomonitoring atmospheric sulfur dioxide using urban tree leaves and foliar dusts in Huizhou, Gongdong province

采用常规采样及碱片挂片法同步监测广东省惠州市大气SO2体积分数,用ICP-AES测定了惠州市不同功能区的2种主要绿化树种大叶榕(Ficus virens Ait var.sublanceolata(Miq.) Corner)、紫荆(Bauhinia blakeana)叶片及其叶面降尘的硫质量分数。结果表明,不同功能区植物叶片和降尘的硫质量分数差异显著,其综合污染指数(PI)以商业交通区、工业区、居住区、清洁区的趋势递减。叶片中硫的质量分数随春、夏、秋季而增长,季节差异显著。植物叶片、降尘中硫质量分数随交通流量的减少而降低。叶片和叶面降尘中硫的质量分数与大气硫酸盐化速率三者显著相关,大叶榕和紫荆与降尘协同生物监测大气SO2的二元数学模型的相关系数分别为R=0.995和R=0.990,明显优于植物与硫酸盐化速率监测SO2的常规一元数学模型。表明大叶榕、紫荆叶片及其叶面降尘均可作为城市区域大气SO2污染的有效指示剂,叶片的长期效益和季节效益显著,降尘则短期效益显著;两者协同监测,可靠性和灵敏度更高,应用前景广阔,可为地方和区域环境监测和评价提供参考。

Using conventional methods, sampling and static suspending piece absorption, to biomonitor the sulfur contents in atmosphere and foliage of Ficus virens Ait ear. sublanceolata （ Miq. ） Comer. and Bauhinia blakeana in Huizhou city, Guangdong province.. The foliar dust of the two plants was determined by ICP-AES. The sulfation rate was measured by the weight of sulfate from different urban areas in Huizhou city. The results showed that sulfur contents in foliage and foliar dust were significantly dif- ferent among the areas, and the pollution index （ PI ） decreased in order： commercial and traffic areas （ CTA ） 〉 industrial areas （ IA ） 〉 residential areas （ RA ） 〉 control areas （ CA ）. Sulfur contents in foliage increased obviously according to season. Sulfur contents in atmosphere and foliar dust varied with the traffic density. Regression analysis indicated that sulfur contents of foliage were evidently correlated with those of foliar dust and atmosphere. The correlation coefficients of dual mathematical model for foliage and foliar dust biominotoring atmospheric SO2 were R = 0.995 （for F. virens Ait vat. sublanceolata （ Miq. ） Comer ）, R = 0.990 （ for B. blakeana ）, respectively, which was superior to the conventional monistic mathematical model. It was suggested that foliage and foliar dust could be efficient indicators for SO2 pollution in urban areas. Foliage may be used as a long-term bioindicator while foliar dust as a short-term one. The two indicators were applied simultaneously in biomonitoring led to much higher reliability and sensitivity, which could be meaningful for environmental protection and monitoring for the local region and urban areas.