我国直辖市畜禽养殖排放类固醇激素特征及其潜在污染风险

The excretion features of manure-borne steroid hormones and their potential risk in the municipalities of China

通过对北京、天津、重庆及上海4个直辖市畜禽养殖的统计分析,借鉴英美等发达国家的相关研究,估算了各直辖市畜禽养殖业类固醇雌激素和雄激素的年排放量,并初步探讨了各市单位耕地面积的类固醇雌激素承载量及类固醇雌激素对地表水体的潜在污染风险.结果表明,4个直辖中,重庆市的雌激素和雄激素年排放量处于4个直辖市之首,2008年两类激素的排放量分别达到1283.0和136.1kg.北京和上海市类固醇激素总排放量均较10年前有所减少,尤其是上海市,10年间类固醇激素排放量减少了1/3.相反,天津市和重庆市的畜禽养殖业类固醇激素排放量却在增长.北京市单位耕地面积畜禽粪便类固醇雌激素的承载量最大,且明显增大,2008年达到839.1mg.hm-2,是1998年的1.5倍.根据英国环保署(Environment Agency,United Kingdom)建议的最低可观测效应浓度10ng.L-1,北京市和天津市的畜禽养殖排泄物有可能对当地地表水系统产生生态危害.在3种类固醇雌激素中,雌酮的排放对耕地承载的贡献最大.因此,各直辖市尤其是北京市和天津市亟需加强规模化养殖业管理,加强畜禽养殖业排污中类固醇激素的去除,保障城市的耕地及地表水生态安全.

The excretion of manure-borne steroid estrogens and androgens in four municipalities of China was estimated in this study by using statistical data and the referenced estimation method in developed countries.Additionally,farmland loading quantities of manure-borne estrogens and the potential ecological risk to local surface water systems from applying animal manure were preliminarily assessed.The largest emission of manure-borne steroid estrogens and androgens were found in Chongqing city,which were 1283.0 and 136.1 kg in 2008,respectively.The emissions of manure-borne hormones in Beijing and Shanghai city decreased from 1998 to 2008,especially in Shanghai city where the emission in 2008 was reduced 33% compared to that of 1998.On the contrary,the excretion in Tianjin and Chongqing city increased.The manure-borne estrogenic load of farmland reached 839.1 mg · hm-2 in 2008 in Beijing,which was the highest among the four cities.According to the recommended limitation of the lowest observable effect level for 17β-estradiol（10 ng · L-1,Environmental Agency of United Kingdom）,the manure-borne estrogens in Beijing and Tianjin city might have become a potential risk to local surface water systems.Oestrone was the largest contributor to farmland load of the three estrogens.Therefore,the regulation of livestock production and development of suitable technologies to reduce the environmental discharge of manure-borne hormones should strengthened in these four municipalities,especially Beijing and Tianjin city.