[Establishment of health risk assessment model for assessing medicinal and edible plants contaminated by heavy metals--take Astragali Radix,Codonopsis Radix and Laminariae Thallus as examples].

With the improvement of living standard,the theory of " medicine and food homology" has developed rapidly in the field of diet,medicine and health preservation. In recent years,many literatures have been reported on the active ingredients and pharmacological effects of medicinal and edible plants,but relatively few reports have been reported on their safety investigation. Therefore,to further evaluate the quality and safety of medicinal and edible plants,Astragali Radix,Codonopsis Radix and Laminariae Thallus were selected as our research objects in this study. Moreover,the pollution level and the potential health risk of heavy metals were deeply assessed in different types of medicinal and edible plants. Especially,the contents of chromium,copper,arsenic,cadmium,mercury and lead in these three herbs were determined by inductively coupled plasma mass spectrometry( ICP-MS),and their health risk level was evaluated by target hazard coefficient method. The results showed that under the international heavy metal limit standard( ISO 18664-2015,GB 2762-2017),the over-standard rates were 25%,77% and 100% in 16 batches of Astragali Radix,26 batches of Codonopsis Radix and 9 batches of Laminariae Thallus,respectively. Besides,the values of target hazard quotients( THQ) for adults and children are 0. 028 244,0. 063 505 and 0. 014 485,0. 032 568 in Astragalus membranaceus and Codonopsis pilosula,respectively,which were higher than the standard values of 0. 02 and 0. 011 25. While,the total heavy metals THQ values for adults and children are 0. 023 734 and 0. 020 287 in Laminariae Thallus,which were much higher than the standard values of 0. 008 0 and 0. 007 5. However,the CR values of As,Cd and Pb in the three herbs were lower than 1×10~(-6). Above results indicated that those six harmful elements have certain health hazards to the exposed population,but there is no potential carcinogenic effect. It can be seen that,there were still presence of the pollution of harmful elements,and it is necessary to establish the reasonable limit standards and quality control methods of medicinal and edible plants in time.