全氟辛酸铵盐（PFOA）对土壤酶活性影响的初步研究

全氟辛酸及其盐类（PFOA）是新近认定的持久性有机污染物之一,虽然对环境的危害愈来愈严重,但鲜见其土壤生态毒理的研究报道。为此采用室内模拟的方法,对PFOA与土壤酶（脲酶、脱氢酶、过氧化氢酶）活性间的剂量-效应关系进行了研究。结果表明,PFOA可显著抑制土壤脱氢酶活性（除5号土样外）,二者关系达显著或极显著负相关,揭示出土壤脱氢酶活性可表征土壤PFOA污染的程度;供试土样PFOA轻度和中度污染时的生态剂量ED10和ED50值分别为31mg·kg-1和151mg·kg-1,而且酸性土壤比碱性土壤对PFOA反应更敏感,表明土壤pH对PFOA的生态毒性有重要影响。PFOA对纯脲酶、土壤脲酶和过氧化氢酶活性影响规律性不明显,总体呈波动性变化,有待进一步研究。

The Effect of Perfluorooctanoic Acid Ammonium Salt on Soil Enzyme Activities

Perfluorooctanoic acid（PFOA）and its salts are considered to a persistent organic pollutan（tPOP）.Its harm to the environment has become serious,however there are few reports on its eco-toxicity.The dose-response relationship between PFOA and soil enzymes（urease,dehydrogenase,catalase）was investigated in a laboratory study.Results showed that PFOA could significantly inhibit soil dehydrogenase activity in all but the 5th soil sample.This indicated that soil dehydrogenase activity could be used as an index of soil pollution by PFOA.The critical PFOA concentrations were 31 mg·kg-1 for slightly polluted soil and 151 mg·kg-1 for moderately polluted.In addition,soil dehydrogenase activity in acid soils was more sensitive than alkaline soils to PFOA.This indicated the important influence of soil pH on PFOA toxicity.PFOA had no significant influence on the activity of jackbean urease,soil urease,catalase.