Yushchenko Poisoning

MYSTERY

Reports that Ukrainian presidential candidate Viktor A. Yushchenko was poisoned with high concentrations of dioxins are preliminary and not yet confirmed by researchers. Yushchenko became ill in September during the Ukrainian presidential race, and two months later, his smooth skin became pocked with a mass of cysts, a symptom of dioxin poisoning.

Abraham Brouwer, professor of environmental toxicology at the Free University in Amsterdam, tested Yushchenko's blood using the CALUX bioassay (chemically activated luciferase gene expression). Brouwer reported on Dec. 15 that he found levels of dioxin or dioxin-like compounds at about 100,000 pg of dioxin toxic equivalents per g of blood lipid, or 100,000 ppt. The average concentration in humans is about 20 ppt. Additional testing using gas chromatography and mass spectroscopy (GC/MS) is under way, but as C&EN went to press, the results were not known.

Until GC/MS results are obtained, the concentration cannot be known accurately. Nor can it be clear whether the poison was a dioxin, a furan, a dioxin-like polychlorinated biphenyl, a hexachlorobenzene, or a halogenated naphthalene, says Arnold Schecter, professor at the University of Texas School of Public Health. CALUX can only indicate the presence of halogenated organics binding strongly to the aromatic hydrocarbon receptor.

Linda S. Birnbaum, director of the Experimental Toxicology Division at EPA's lab in North Carolina, says that if Yushchenko were poisoned with pure 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic form, he would not have felt sick the next day, as is reported to have been the case. It takes several months for symptoms of TCDD poisoning to appear. But if the TCDD were contaminated in some way, or if Yushchenko ingested a small amount of electrical transformer oil containing PCBs, he might have fallen ill almost immediately, she says.