京津地区土壤中新烟碱类农药的含量特征与环境行为

Neonicotinoid pesticides are a group of pesticides most rapidly increased at home and abroad in recent years and they are widely used in agriculture and gardening. However,the resistance to neonicotinoid pesticides as well as other negative effects also appeared gradually, particularly the harm to pollinating insects such as honeybee has caused the worldwide attention. Multiple countries and organizations have taken actions and re-evaluate the environmental risk of some neonicotinoid pesticides. Based on field sampling and laboratory simulation,this project aims to study the concentration level, space distribution characteristic, the relationship with soil property, the change over season, and the transport and transformation rule of neonicotinoid pesticides in the soil of Beijing and Tian area. The objectives are to master the situation of neonicotinoid pesticides in the soil of Beijing and Tian area, to reveal the sorption property, mechanism and influencing factors of neonicotinoid pesticides in the soil, to investigate the leaching ability and influencing factors of neonicotinoid pesticides in the soil, to elucidate the biodegradation rate, pathway and influencing factors of neonicotinoid pesticides in the soil. This project is important to further understand the ecological environmental risk and human health risk of neonicotinoid pesticides, and will provide guidance to remediation of the contaminated soil.

新烟碱类农药是近年来国内外增长最快的一类杀虫剂，被广泛用于农业和园艺，然而其抗性等负面作用也逐渐显现出来，尤其对蜜蜂等传粉昆虫的危害，已引起世界范围的关注。多个国家和组织已经开始采取行动，对一些新烟碱类农药的环境风险进行重新评审。本项目拟结合野外采样实测和室内模拟实验，对京津地区土壤中十种新烟碱类农药的含量水平、空间分布特征、与土壤理化性质的关系、随季节的变化、以及迁移转化规律等进行研究，目标是掌握京津地区土壤中新烟碱类农药的状况，揭示土壤对新烟碱类农药的吸附性能、机制与影响因素，考察土壤中新烟碱类农药的渗滤能力及其影响因素，阐明土壤中新烟碱类农药的微生物降解速率、途径及其影响因素。本项目研究对进一步了解新烟碱类农药的生态环境风险和人类健康风险具有重要意义，并为污染土壤的修复提供指导。

新烟碱类农药是近年来国内外增长最快的一类杀虫剂，被广泛用于农业和园艺，然而其抗性等负面作用也逐渐显现出来，尤其对蜜蜂等传粉昆虫的危害，已引起世界范围的关注。多个国家和组织已经开始采取行动，对一些新烟碱类农药的环境风险进行重新评审。本项目结合野外采样实测和室内模拟实验，对京津地区土壤中九种新烟碱类农药（吡虫啉、啶虫脒、烯啶虫胺、氟啶虫酰胺、噻虫啉、噻虫嗪、噻虫胺、呋虫胺、氯噻啉）的含量水平、空间分布特征、影响因素、以及迁移转化规律等进行了研究，并研究了土壤中新烟碱类农药对土壤微生物的生态风险和对人群的健康风险。结果显示，京津地区土壤中检出率和平均含量最高的为吡虫啉（> 95%，70.32 ng/g），其次为噻虫嗪（> 60%，40.93 ng/g）、啶虫脒（> 65%，5.08 ng/g）和噻虫胺（> 30%，5.28 ng/g），其它的检出率和平均含量均较低。同一季节天津地区土壤中新烟碱类农药的平均含量高于北京地区。春季天津土壤样品中新烟碱类农药的检出率和平均含量均高于秋季。从土地利用类型看，土壤中新烟碱类农药含量有如下规律: 大棚 > 果园 > 露天农田 > 公园 > 住宅。土壤中新烟碱类农药含量和有机碳含量的相关性不显著。双室一级动力学模型可以较好地拟合新烟碱类农药在土壤上的动态吸附过程，Freundlich模型可以较好地拟合新烟碱类农药的吸附等温线，吸附的主要作用力为氢键和范德华力。土壤中新烟碱类农药有较强的渗滤能力。新烟碱类农药在土壤中会被微生物降解，土壤含水量、pH值等对新烟碱类农药的降解均有一定影响。新烟碱类农药及其降解产物会改变土壤微生物的群落结构和功能多样性。项目研究对新烟碱类农药的环境风险评价和污染土壤修复等具有重要的科学意义。