Tea: Chernobyl's lingering legacy.

Cay (Anatolian tea that rhymes with buy) is to Turks what coffee is to Americans -- the caffeinated lifeblood of society. So when cesium-137 fallout from the Chernobyl nuclear accident peppered Turkey's eastern Black Sea coast, a prime tea-growing region, concern about the potential for national exposure to radioactivity mounted quickly. Now, M. Yaaar Unlu and his coworkers at Cekmece Nuclear Research and Training Center in Istanbul report that drinking tainted tea appears to offer a very effective pathway for picking up nuclear fallout. They describe their findings in the January Health Physics.

The Cekmece team found that new tea shoots forming at the time of the Chernobyl accident -- May 1986 -- incorporated enough cesium to produce a peak radioactivity of up to 25,000 becquerels per kilogram (Bq/kg) of dry leaves. By 1992, cesium activity in new shoots had dropped to 200 Bq/kg.

What does that mean for the average Turkish tea drinker? Whole-body exposures to cesium from a year's cay drinking in 1986 may have amounted to 0.66 millisieverts, Unlu's team calculates. That's equivalent to the extra background radiation (from cosmic rays) incurred by living at Denver's altitude for 2.5 years instead of residing at sea level, explains Tom Koval of the National Council on Radiation Protection and Measurements in Bethesda, Md. By 1992, fallout contamination of new Black Sea tea shoots had dropped to levels that would yield an annual cesium dose just one-tenth that delivered by equivalent aay consumption 6 years earlier.