Concentrations and health risk of polycyclic aromatic hydrocarbons in tea.

Sixteen polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured in 8 brands of tea and in infusions of one brand of black tea. It was observed that the total contents of the 16 PAHs (summation PAHs) in the tea samples ranged from 323 to 8800 microg/kg with the highest summation PAHs found in a black tea. PAHs (3-4 rings) were dominant in all tea samples, with a contribution of 77.7-98.7% of the summation PAHs. Infusion times from 10 to 120 min were studied during which 3.03-7.69% of the total PAHs contained in the black tea was released into the liquor. The percentages of PAHs released (RR) from the tea into the liquor were inversely proportional to the lgK(ow) of the PAHs with a mean formula of RR=261.7/lgK(ow)-41.32 and R=0.899. To analyze the potential health risk, sanitary standards of the 16 PAHs for tea leaves were calculated to be 0.1-110 mg/kg and the daily PAHs intake from the black tea was calculated to be 6.36 microg per person.