环境污染分为非生物污染和生物污染,后者是指生物体释放出的有毒有机化学物质,如花粉致病物。豚草(包括普通豚草和三裂叶豚草)是全世界广泛传播的恶性有毒杂草,起源于北美,植株高大,生活和适应力强。环境适宜,缺乏生物平衡(抑制)因子,极易造成“生态爆发”,形成单一优势群落。豚草是人类变态反应症(也称花粉症)的主要致病源,出现过敏性鼻炎、哮喘、皮炎等症状。由于无特效药治疗,欧美国家一些病人只能暂避外地或永离故土,成为社会及环保重大问题。美国人群发病率已达2％～ Environmental pollution is divided into non-biological pollution and biological pollution, the latter refers to the organisms released toxic organic chemicals, such as pollen pathogenic substances. Ragweed (including Common Ragweed and Crassulaceae) is a worldwide and widespread malignant toxic weed that originated in North America, with tall plants and strong living and adaptability. Environmentally appropriate, the lack of biological balance (inhibition) factor, can easily lead to “ecological outbreak” to form a single dominant community. Ragweed is the main source of human allergies (also known as hay fever), allergic rhinitis, asthma, dermatitis and other symptoms. Because there is no cure for cure, some patients in Europe and the United States can only temporarily avoid their homeland or leave their homeland forever, becoming a major social and environmental issue. The incidence of the American population has reached 2% ~