重庆市主要食用菌的重金属含量及评价

重庆市的主要食用菌重金属的平均含量为：铅〉镉〉汞〉砷，均低于国家食用菌卫生限量标准GB7096-2003，说明重庆市食用菌的重金属含量总体上是安全的。但是，有12％样品的铅含量和19％样品的汞含量超过国标。食用菌品种不同，其重金属的含量差异很大，铅、镉、汞、砷的平均累积量依次为：蘑菇〉鸡腿菇〉香菇〉姬菇〉平菇〉金针菇．大部分符合国家卫生标准的要求。此外，食用菌的重金属含量呈现出主城区〉远郊区≈近郊区的趋势，这种现象可能与栽培环境有关。值得注意的是，食用菌重金属含量的变异系数极大，说明环境条件、品种和栽培技术影响重金属在食用菌中的累积。采用优良品种，选择安全的生产环境，改革栽培技术可能降低食用菌的重金属含量。

ANALYSIS AND ASSESSMENT OF HEAVY METAL POLLUTION IN EDIBLE MUSHROOMS FROM CHONGQING

Samples of edible mushrooms were collected from different areas of Chongqing Municipality and their heavy metal contents were determined.The mean contents of the 4 heavy metals studied(Pb,Cd,As and Hg) in the edible mushroom samples were all below the regulated criteria stipulated in the National Standard of China and appeared in the order of Pb >Cd >Hg >As.However,Pb in 12% of the samples and Hg in 19% of the samples were above the regulated criteria.Heavy metal contents varied substantially with mushroom species,the average heavy metal accumulation was greatest in Aragicu bisporus(lange) Sing.,followed in sequence by Coprinus comatus(Fr) S.F.Gray,Lentinus edodes(Berk.) Peglerl,Pholiota maneko,P.ostreatus and Flammubine velutipes(Curt.Ex.Fr.) Sing.Mushroom samples from the city area tended to have higher heavy metal concentration than those from the near or remote suburbs,which were similar to each other,sug gesting that heavy metal contents of the mushroom might be associated with their growing habitats.What is worth mentioning is that the variation coefficients of heavy metal concentrations were quite great,indicating that environment,cultivation practices and varieties may influence heavy metal accumulation.Therefore,it seems possible to decrease heavy metal contents in edible mushrooms by the use of good varieties and by improving the cultivation techniques in non-polluted environment.