香菇中重金属含量风险分析及栽培基质对重金属累积的作用

为探究北京市市场流通中食用香菇重金属含量情况及对人体的健康影响,采集北京市流通领域中107份香菇样品,测定了镉(Cd)、砷(As)、汞(Hg)、铅(Pb)的含量水平,依据靶标危害系数方法(THQ)评价了香菇通过膳食途径摄入4种重金属的人体健康风险;同时通过栽培基地采样,研究了栽培基质与香菇中重金属含量的相关性。结果显示:采集的香菇样品中重金属Cd、As、Hg、Pb的含量范围分别为ND～0.76、0.01～0.30、ND～0.03、ND～1.79 mg·kg~(-1),Cd和Pb的超标率均为5.6%,而Hg和As未出现超标情况;鲜食与干食香菇的重金属含量没有显著性差异;香菇子实体中Cd、As、Pb含量与基质重金属含量呈现极显著相关,香菇中Cd的富集系数最高,分别是As、Hg、Pb的3.70、5.67、1.63倍;香菇4种重金属的THQ均未超过安全阈值,儿童经香菇途径摄入As的THQ值相对较高,需引起注意。北京市流通领域香菇的主要污染因子是Cd和Pb,栽培基质中的Cd更易被香菇子实体吸收并累积。

Risk assessment of heavy metals in Lentinula edodes and the role of substrate in accumulation of heavy metals

In order to investigate the heavy metals content in Lentinula edodes in the Beijing market and its dietary effect on human health, 107 fungi samples were collected. The levels of Cd, As, Hg, and Pb were measured, and the dietary risks of the four heavy metals to human health were evaluated through the target hazard quotient (THQ) method. Additionally, the correlation between the heavy metals contents in the cultivation substrate and those in L. edodes was studied. The results showed that the contents of Cd, As, Hg, and Pb in the collected samples were ND~0.76, 0.01~0.30, ND~0.03 mg·kg^-1, and ND~1.79 mg·kg^-1, respectively. The over-standard rates of Cd and Pb were both 5.6%, while no Hg or As contents exceeded the standard. No significant differences were observed between the heavy metals contents in fresh and dried mushrooms. The contents of Cd, As, and Pb in the fruiting bodies of L. edodes were significantly correlated with those in the substrate. The enrichment coefficient of Cd is the largest, which is 3.70, 5.67 and 1.63 times of As, Hg, and Pb, respectively. The THQs of the four heavy metals were all within the safe threshold, but it was noteworthy that the THQ of As for children was relatively high. Therefore, the major pollution factors of L. edodes in circulation in Beijing were Cd and Pb, and Cd in the cultivation substrate was more easily absorbed and accumulated by the fruiting body of L. edodes.