徐州地区双孢蘑菇覆土中重金属含量测定及其污染评价

为了解徐州地区双孢蘑菇覆土重金属污染状况,选取睢宁县官山镇(SNGS)、泉山区桃园街道办事处(QSTY)、贾汪区江庄镇(JWJZ)、丰县欢口镇(FXHK)4个主栽区,采集48个覆土样品,分别测定其重金属Pb、Cd、As、Hg含量,并进行污染评价。结果表明:QSTY和FXHK覆土中As、Hg含量和FXHK覆土中Cd含量均高于土壤背景值,其中Cd含量达到土壤背景值的2.062倍;4个主栽区覆土中4种重金属的单因子污染指数和综合污染指数分别小于1.0和0.7,显示覆土污染等级为安全;而As含量分别与Pb、Cd含量呈显著和极显著正相关,Pb与Cd含量间呈显著正相关,说明这几种元素存在复合污染的可能,且主要来源于成土母质和农业活动。由此可见,该地区4个双孢蘑菇主栽区覆土重金属质量属于清洁水平,符合无公害食用菌生产条件。

Heavy Metal Contents and Pollution Evaluation of Agaricus bisporus Covering Soil in Xuzhou

To understand the pollution state of heavy metal in Agaricus bisporus covering soil in Xuzhou,forty-eight covering soil samples from Guanshan town of Suining county(SNGS),Taoyuan substrict office of Qianshan district(QSTY),Jiangzhuang town of Jiawang district(JWJZ) and Huankou town of Feng county(FXHK) were collected to determine the contents of Pb,Cd,As and Hg and further to evaluate their pollution status.The results showed that the contents of As and Hg in QSTY and FXHK,and Cd in FXHK covering soils were higher than their own background values.The content of Cd in FXHK covering soil was 2.062 times higher than its corresponding background value.Single pollution indexes and comprehensive pollution indexes of 4 heavy metals in 4 main plantation areas were all lower than 1.0 and 0.7,respectively.The conclusion noted that pollution grade of these covering soils was safe.The content As was significantly positively correlated with that Pb and Cd,and The content Pb was significantly positively correlated with that Cd.The correlation suggested that these elements from soil-forming parent materials and farming practices might cause compound heavy metals pollution.Thus it could be seen that heavy metal quality of covering soil from 4 main plantation areas of Agaricus bisporus in Xuzhou area was at clean level,and was in accordance with safe production conditions of pollution-free edible fungi.