粪源雌激素环境归趋的13C同位素示踪及其生态效应研究

Natural estrogens are classified as endocrine disrupting chemicals. Currently, there is growing alarm about the side effects of estrogens on wildlife and humans as, for instance, the increasing rates of breast cancer in women, increase of abnormalities in the reproductive system, and different expressions of biological disorders such as feminization and decreased fertility. When excretion is applied to agricultural fields according to the rules of good agricultural practice, natural estrogens in animal wastes may spread and bioaccumulation in environment, which causes the challenge for safe perspective about the usage of animal wastes. Among natural estrogens, 17β-estradiol (E2) is most physiological active substance. The present study was designed to reveal estrogens distribution characterization and ecological effects in soil system and assess agricultural product safety. The work developed potted plant experimentation amended with spiked 17β-estradiol-4-13C cow manure in the simulative conservatory. The samples were determined by stable isotope tracer. The objectives of this study were to: (i) disclose transport and distribution rules of estrogens in soil-vegetable- earthworm-leakage water system; (ii) discover estrogens bioaccumulation and ecological effects in vegetable and earthworm; and (iii) evaluate earthworm indicators as tools for soil pollution monitoring. It would facilitate optimizing management practices of animal excrement to guarantee safe use. It has also important academic and practical significance to understand estrogens pollution in agricultural product safety and environmental protection.

养殖业类固醇激素等特征内分泌干扰物，随粪肥不断进入环境富集在土壤中，具有紊乱激素分泌、造成生育能力降低以及诱发乳腺癌的作用，使畜禽粪便的安全利用前景受到新的挑战。本项目以雌激素中最具生物活性的17β-雌二醇(E2)为研究对象，利用13C稳定同位素标记技术：① 揭示养殖业粪源类固醇雌激素等内分泌干扰物在粪便-土壤-叶菜-蚯蚓-渗漏水系统中的行为归趋，如迁移、分布和分配规律及影响因素；② 探明养殖业类固醇雌激素E2亚致死或污染水平下，在叶菜和模式生物体内的累积及生态效应，如E2被富集后的内分泌干扰效应，模式动物在分子和基因水平的生理响应等；③ 评价模式动物体内微观分子敏感指标作为生物标志物在土壤E2污染监控中的应用。为保障养殖场畜禽粪便资源化的安全利用提供科学依据，对于促进农业环保领域和农产品安全中关于雌激素污染问题的研究具有重要的学术价值和现实意义。

畜禽养殖污染已成为全国重点污染领域之一。据估算，我国养殖每年产生近40亿吨畜禽粪便，《畜禽养殖业污染物排放标准》（GB 18596-2001）、《畜禽规模养殖污染防治条例》未对废弃物中的激素等污染物排放做出规定，造成畜禽废弃物中激素等污染物释放入环境，所带来对生态环境、农产品质量安全和人体健康等的风险日益凸显。.目前，我们对畜禽养殖业中类固醇激素等特征内分泌干扰物环境污染缺乏清晰认识。本项目以17β-雌二醇(E2)为研究对象，利用稳定同位素标记示踪技术和液质谱串联技术，开展粪源类固醇雌激素的环境行为与效应研究，建立了检测类固醇雌激素E2的液质串联法，构建了稳定同位素标记粪肥的土壤-叶菜-蚯蚓-渗漏水盆栽系统，研究了雌激素E2在系统中的环境迁移行为，雌激素E2胁迫对叶菜生长的影响，及在叶菜中富集和吸收特征，通过细胞体外培养法评估了雌激素E2生物效应，并研究了雌激素E2对土壤模式生物蚯蚓的影响。结果显示：畜禽废弃物中E2在灌溉水和动物活动中在系统内被再分配，在土壤中迁移吸附，与植株根系交换被吸收，同时水的淋溶作用促使其解吸附，具有污染深层土壤或者地下水潜能；E2处理浓度与叶菜种子发芽率和根长呈反比，植株抗氧化酶系统活性、丙二醛和脯氨酸含量等随E2处理浓度增加，叶菜根部E2累积量高于可食部分，并与处理浓度正相关；E2可诱导体外培养的MLTC-1细胞连接打开和凋亡，提高MCF-7细胞的增殖活性；在粘土和沙壤土中，E2污染能引起土壤模式生物蚯蚓酶活性变化，沙壤土受到的影响更为显著。.通过项目实施，明晰了畜禽废弃物中风险因子环境行为和生物效应，为养殖场动物粪便安全利用提供了重要的科学支持，对指导农业生产，提高农产品质量水平，保障和促进产业健康发展，具有重要的学术意义和现实意义。