Tea (Camellia sinensis L) is one of the most widely popular
nonalcoholic beverage, consumed by over two-thirds of the world's population due to its
medicinal, refreshing and mild stimulant effects. Mainly four types of made tea viz., black or
red, oolong, green and white are used for tea infusion (water extract from fermented tea leaf)
worldwide. Tea plays a major role in terms of the intake of a number of nutritional trace
elements in humans. Besides essential macro- and microelements. experimental studies have
demonstrated that the accumulation of significant amount of excess nonessential trace elements in
tea leaves may eventually increase the metal body burden in humans. Different literatures have
indicated that among different trace elements, levels of aluminium (Al). arsenic (As), cadmium
(Cd), chromium (Cr), copper (Cu), fluoride (F) manganese (Mn), and nickel (Ni) in different tea
infusions were 0.06-16.82 mg L(-1), trace-1.53 mu g L(-1), trace-0.79 mu g L(-1), below
detectable limit-43.2 mu g L(-1), 0.02-40.0 mg L(-1), 0.2-4.54 mg L(-1), 0.1-250 mg L(-1) and
BDL-0.16 mg L(-1). respectively. It has also been reported that in some of the tea infusions,
toxic metals exceed the maximum permissible limits stipulated for different countries. In the
present review, an attempt has been made to update and evaluate the knowledge of the presence of
some selected trace elements in tea leaves, made tea and tea infusion, based on the available
literature. Existing reports suggested that the presence of trace elements in green tea is lower
than the black tea in most cases. However, the available literatures still appear to have some
limits and may need more detailed investigations before reaching the conclusions. (C) 2010
Elsevier Ltd. All rights reserved.