高铜、高锌猪粪对蚯蚓的急性毒性效应研究

测定了高Cu、高Zn猪粪条件下Cu、Zn单一与复合污染对蚯蚓的急性致死及亚致死效应.结果表明,Cu、Zn浓度与蚯蚓死亡率显著正相关(a=0.05,r_Cu=0.99,r_Zn=0.99),与体重增长率显著负相关(a=0.05,r_Cu=-0.99,r_Zn=-0.96).蚯蚓个体对Cu、Zn的耐受程度不同,其毒性阈值(引起蚯蚓个体死亡浓度)分别为:Cu250mg·kg^-1、Zn400mg·kg^-1.LD₅₀分别为:Cu646.68mg·kg^-1、Zn947.38mg·kg^-1.复合污染情况下,Cu浓度为250、500mg·kg^-1时,Cu、Zn复合污染表现为协同效应;Cu浓度为750mg·kg^-1时,Cu、Zn复合污染表现为拮抗效应,可见,猪粪中Cu、Zn复合污染的毒性效应与各组浓度组合密切相关.

Acute toxicological effects of excessive Cu and Zn-containing in pig manure on earthworm

Cu and Zn are popularly used as additives in animal feed in China,which could result in their excessive accumulation in manure to a toxic level,and thus,possibly threaten the environment when the manure is applied to farmland.In this paper,the acute and sub-acute lethal effects of pig manure with excessive Cu and Zn on earthworm were studied,and the results indicated that the concentration of Cu and Zn in pig manure had a significantly positive correlation with the mortality of earthworm,while a significantly negative correlation with earthworm growth rate.The individuals of earthworm had different tolerance to excessive Cu and Zn,with the threshold values causing death being 250 mgkg~(-1) and 400 mgkg~(-1)for Cu and Zn,respectively.The LD_(50) was 646.68 mgkg~(-1) for Cu,and 947.38 mgkg~(-1) for Zn.A strong synergistic effect was observed under the combined pollution of 250 mgkg~(-1) for Cu and 500 mgkg~(-1) for Zn,whereas antagonistic effect happened when 750 mgkg~(-1) for Cu was supplied,suggesting that the joint toxic effects of Cu and Zn on earthworm were closely correlated to their concentrations in pig manure.