Recently several allegations emerged that the Ayurvedic herbal products contain harmful levels of heavy metal contents that can cause deleterious effects in human beings. On the basis of this, researches were also done in India and abroad about the heavy metal contamination of raw drugs and plants showed heavy metals exceeding permissible limits. Heavy metals taken up in the study are non essential for plant physiology. Pollution can contaminate air, water and soil with heavy metals. Also the plants can absorb the heavy metals found in high amount to some extent. Punarnava is well known medicinal plant, used widely in Ayurvedic medicines. It is a common as well as non-cultivated plant growing widely in the agro-climatic conditions in Kerala. Here the study was designed as analytical cross sectional design and the objective was to analyse the presence of specified heavy metals i.e. lead, mercury, arsenic and cadmium in various samples of punarnava (Boerhaavia diffusa Linn.). Samples are collected in stratified random sampling method. Samples were collected in 3 groups A, B and C i.e. market samples, genuine samples and samples from polluted area. Again these groups are divided in to 3 i.e. highland, midland low lands according to the geographical peculiarities in the districts of Kerala. Collected samples were made in to coarse powder and finally analysed using atomic absorption spectro photometer (AAS). Results were analysed using the statistical tools. All the heavy metals analysed were within the permissible limits. Arsenic and mercury were below detectable range in 3 groups. Lead and cadmium in the third group i.e. Samples taken from polluted areas shows significant increase compared to the other 2 groups. Polluted samples for lead and cadmium taken from mid land show the high value.
Dr. Preethi Mohan, “A cross sectional study on presence of heavy metal content in Punarnava (Boerhaavia diffusa Linn.)”, International Journal of Research in Alternative Medicines, vol. 1, pp. 12–20, 2014.