Meta analysis of heavy metal and pesticide pollution status of nine medicinal and edible substances

Abstract

ObjectiveTo evaluate the heavy metal and pesticide pollution status of nine medicinal and edible substances， including Eucommia ulmoides leaves， Codonopsis pilosula， Cistanche deserticola， Dendrobium candidum， Astragalus membranaceus， Panax quinquefolium， Gastrodia elata， Ganoderma lucidum， and Corni Fructus.MethodsPubMed， China National Knowledge Network （CNKI）， VIP， and Wanfang databases were searched to obtain research literature published from 2000 to 2022 on heavy metals， pesticides， and environmental pollutants in nine medicinal and edible substances. The literature was screened according to the inclusion and exclusion criteria， and the included studies were analyzed and pooled into estimates using meta-analysis.ResultsA total of 106 studies encompassing seven heavy metals， including lead （Pb）， cadmium （Cd）， mercury （Hg）， arsenic （As）， chromium （Cr）， copper （Cu）， and nickel （Ni）， and 42 pesticides， including organochlorine， pyrethroid， and organophosphorus， of nine types of medicinal and edible substances used as food collected from 23 provinces （municipalities） were comprehensively analyzed. The average heavy metal content in the medicinal and edible substances used as food was 0.22 mg/kg （95%CI： 0.13~0.39）， and the average heavy metal content of Eucommia ulmoides leaves was the highest （2.80 mg/kg， 95%CI： 0.75~10.37）， followed by Dendrobium candidum with an average value of 0.30 mg/kg （95%CI： 0.18~0.49）. The average value of heavy metals in the other medicinal and edible substances was lower than 0.30 mg/kg. Among the seven heavy metals analyzed， the Cu exhibited the highest content， followed by Cd and Pb. Subgroup analysis showed that the contents of the seven heavy metals in medicinal and edible substances collected from different locations had high heterogeneity （P<0.05）. The meta-analysis showed that heterogeneity existed in the mean values of 42 pesticides （P<0.05）， and the total mean values of pentachloronitrobenzene， BHC and DDT in Dendrobium candidum， Panax quinquefolium， Cistanche deserticola， Astragalus membranaceus， and Gastrodia elata were the highest.ConclusionThere are differences in the categories and contamination levels of heavy metals and pesticides in medicinal and edible substances. Heavy metal pollution is related to the origin and type of medicinal and edible substances. Prohibited pesticides can be detected in certain medicinal and edible substances， and further traceability analyses of pollutants in medicinal and edible substances should be conducted. The supervision and monitoring of the production and processing of medicinal and edible substances should be strengthened.

Keywords

• medicinal and edible substances
• heavy metals
• pesticides
• meta-analysis