Analysis of heavy metal content in Lentinula edodes and the main influencing factors

Abstract Lentinula edodes is the second largest edible mushroom species in the world and an important medicinal fungus. However, the content of heavy metals in this edible mushroom has attracted increasing attention from consumers. To fully understand the heavy metal content in Chinese L. edodes and the risk of consumption of L. edodes to human health, the contents of four important heavy metals (Pb, As, Hg, and Cd) in L. edodes samples from 27 counties in 14 provinces of China were analyzed. The pollution degree of these four heavy metals was analyzed by single factor pollution index and comprehensive factor pollution index. The target hazard quotients (THQ) method was used to calculate the compound risk of exposure to multiple heavy metals. The production factors that may affect the Cd content in fruiting bodies of L. edodes were further analyzed. The results show that all four heavy metals were detected in all samples, but the contents of Pb and Hg were far lower than the national standard threshold, while 3.57% and 18.33% of As and Cd, respectively, exceed national standards. Single factor pollution index analysis showed that all four heavy metals were at a safe level, while comprehensive factor pollution index analysis showed that Pb and Hg were at a safe level and As and Cd were at the level of light pollution. The target hazard quotient thresholds of the four heavy metals all remained within a safe range, but the amount of heavy metals ingested by children was higher than that by adults. Production factors such as cultivation regions, substrate, cultivar, and cultivation mode were found to influence the content of Cd in fruiting bodies.