Dioxin Concentrations in Commercial Health Tea Materials in Japan

Abstract

This study determined the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) in five selected plant materials [dokudami (from houttuynia herb), rose hip (from rosa fruit), ebisugusa (from cassia seed), rooibos, and tochu (from eucommia leaf)] used as health teas in Japan. The toxic equivalent (TEQ) levels for dioxins in the samples ranged from <0.001 to 0.27 pg-TEQ/g weight, when undetectable and trace amounts were taken as zero. The mean of total TEQ level in commercial tea materials was estimated as 0.08 pg-TEQ/g (n=5). The total TEQ in these samples was mainly dominated by the levels of PCDD/Fs (representing ca. 80% of the total TEQ).