Science News - December 15, 2004

The added danger of counterfeit cigarettes

As if smoking isn’t risky enough, people who smoke “counterfeit” cigarettes are exposed to increased concentrations of heavy metals, including the human carcinogens, cadmium, nickel, and arsenic, according to research recently posted to ES&T’s Research ASAP website (es049038s).

Counterfeit cigarettes, which are packaged to mimic legitimate brands, accounted for 5% of 2000–2001 sales in the United Kingdom and substantially more in subsequent years, according to W. Edryd Stephens of the University of St Andrews (Scotland), the corresponding author of the new research. The tobacco in the counterfeits is highly heterogeneous and probably comes from multiple sources in the Far East or the Balkans, says Stephens. Analyses of stable carbon and nitrogen isotopes in the counterfeits suggest that the most likely origin of the excess metals is from heavy applications of cheap, contaminated phosphate fertilizers.

Nitrate fertilizers and fertilization with sewage sludge may also contribute to the problem, says Stephens. Moreover, legitimate tobacco companies monitor tobacco, refusing to purchase tobacco with high metal levels, according to Dana Bolden, a brand integrity spokesperson for cigarette manufacturer Philip Morris. This rejected tobacco may end up in the illicit products, speculates Stephens.

Tobacco is a metal accumulator, especially when it is grown in acidic soils. For example, tobacco plants take up cadmium from the soil and concentrate the metal, primarily in their leaves. In addition, the sticky nature of tobacco leaves enables them to retain particles of metal-rich surface dust throughout the entire manufacturing process, says Stephens.

When a cigarette is lit, metals such as cadmium end up in the smoke, notes Stephens. Cadmium is inhaled by the smoker and by nonsmokers exposed to secondhand smoke, explains Eliseo Guallar of Johns Hopkins University’s Bloomberg School of Public Health. In addition to cadmium’s carcinogenicity, “peripheral arterial disease is increased about fourfold in smokers, and this increase is partly mediated by cadmium in smoke,” says Guallar.

In the ES&T study, Stephens measured concentrations of metals in 47 counterfeit cigarettes that British Customs and Excise had seized. The metal concentrations were compared with levels in the eight genuine brands of cigarettes they mimicked. Cadmium levels in the counterfeits averaged 3.0 milligrams per kilogram, compared with 0.6 in genuine brands. Arsenic and lead levels were also consistently higher. In addition, the metal levels in the counterfeits varied widely, whereas values in legitimate cigarettes were consistently low, notes Stephens. While expressing some reservations about the precision of the analysis method, Jorge Gardea-Torresdey, an expert on metal uptake by plants at the University of Texas at El Paso, does not dispute Stephens’ major conclusions.

Counterfeits are also a problem in the United States, indicates an official with the Bureau of Alcohol, Tobacco, Firearms and Explosives, explaining that counterfeits enter on shipboard containers, via Mexico, and through Internet mail-order, primarily from China. In 2003, cigarettes headed the list of counterfeit seizures, with a domestic value of $41.7 million, according to U.S. Customs and Border Protection.

The first international treaty to set a global agenda for regulating tobacco products is the Framework Convention on Tobacco Control; it is sponsored by the World Health Organization. On November 29th, 2004, Peru became the 40th nation to ratify the treaty, thereby assuring that it will go into effect in 2005. Although both the United States and the United Kingdom signed the treaty, neither has ratified it. —BARBARA BOOTH