Contaminations of Heavy Metals in Tea Leaves, Finished Tea Products and Liqour in Gilan Province, Iran

Tea is drunk by most of Iranian people. It is widely cultivated and consumed in the north of Iran. Although tea is rich in many trace inorganic elements, probably some toxic elements also are present in tea leaves due to polluted soil, application of pesticides, industrial activities or fertilizers. As the significant amount of tea consumed (several times in a day) it was necessary to determine the toxic metal contents. To assess the levels of Zinc, Copper, Cadmium and Lead in Tea leaves and finished tea products, 100 samples after harvesting from 12 major Tea farms mostly in 5 cities (Ladhijan, Siahkal, Langerud, Rudsar , Foman) in Gilan province in the north of Iran and 50 samples from 5 Tea Factories in 2012 were randomly collected. Soil samples were collected at each place and time the tea leaves were plucked and soil mixed thoroughly to give a represent able fraction. Analysis of variance (ANOVA) was employed to detect significances among samples from different forms of tea samples (Black tea, tea leaves). Soil results showed that the Cadmium contents in the soil samples collected from all farms in 5 cities in the Gilan province are higher than WHO permissible levels and the mean content of Cadmium in all tea leaves samples is over, while Lead, copper and zinc contents were below the maximum permitted level for making tea has the significant role (p < 0.003) in decreasing the cadmium content.