Study on heavy metals in some Ayurvedic herbal products and risk assessment of their calculated average daily dose intake in humans

Abstract

IntroductionAccording to the World Health Organisation, 80% of the world population relies on plant material based herbal medicines for primary health care. Nine herbal products used in Ayurvedic medicine were studied for heavy metal content and assessed for their health risks. MethodsNine herbal plant products Tagar (Valeriana jatamansi), Arjun (Terminalia arjuna), Guggulu (Commiphora wightii), Pushkarmoola (Inula racemosa), Shilajeet (Asphaltum punjabianum), Shallaki (Boswellia serrata), Haritaki (Terminalia chebula), Neem (Azadirachta indica), and Bahera (Terminalia bellirica), were collected from the local market and analyzed for heavy metals (Cd, Pb, Zn, Ni, Fe, Cu, Mn, Cr) using Atomic Absorption Spectrophotometer. The risk assessment of heavy metals in Ayurvedic herbal products in terms of the Average Daily Dose was calculated to assess the long-term consumption risk of the medicine, the estimated daily intake (EDI) was determined and the health risk due to the consumption of herbal medicine is described in term of target hazard quotient (THQ). The health risk of each herbal medicine due to the cumulative effect of the heavy metals was assessed in terms of hazard index (HI). ResultAll the Ayurvedic products tested contained heavy metals, in low quantities. Chromium was below the detectable limit. Discussions and conclusionsIn terms of standards given by various agencies for heavy metals dietary intake the studied Ayurvedic products when consumed in the recommended dose were found to contain heavy metals within the standard limits and pose insignificant health risks (HI= >1). The essentiality of certain heavy metals at low and ultra-low concentrations, for proper growth and physiological functioning in animals, is discussed. The study concludes that the human uptakes of heavy metals through the recommended medicinal dose of the studied Ayurvedic plant products are within the safe limits recommended by various agencies and pose a minimal health risk in short term as well as in long term consumption.