Tobacco contains highly toxic compounds not regulated by law

Researchers from the University of Alicante (Spain) have analysed ten brands of cigarettes and found that the concentrations of certain harmful and carcinogenic substances vary significantly from one brand to another. Until now legislation has not covered these compounds and only establishes limits for nicotine, tar and carbon monoxide. Scientists have also developed catalysts to reduce the harmful products in tobacco.

In accordance with current legislation, cigarette packets indicate the nicotine, tar and carbon monoxide concentrations in order to confirm that these do not exceed permitted levels. However the quantity of these substances is not always proportional to the toxicity levels of many other compounds¸ "therefore more suitable parameters are required for determining the toxicity level of tobacco".

This is a conclusion of a study by chemical engineers at the University of Alicante (Spain), published in the journal Food and Chemical Toxicology. The researchers analysed the gases and particulate matter –tar– from ten commercial brands of blond tobacco cigarettes:seven American or British brands (Marlboro, Winston, Chesterfield, Camel, L&M, Lucky Strike and John Player) and three Spanish brands (Fortuna, Ducados and Nobel).

"Although the products generated appear similar, the relative performance (mg/cigarette) of certain highly toxic and carcinogenic compounds varies considerably from one brand to another", highlights to SINC María Isabel Beltrán, one of the authors.

According to the study, the proportion of compounds detected in the gases is maintained in each packet type, but there are some that do not follow this tendency, such as isoprene, chrotonaldehyde and toluene, which are among the most carcinogenic and harmful ones.

The situation is similar in the case of particulate matter. The individual performance of these compounds is correlated with the global performance for each brand, but certain harmful substances, such as hydroquinone and cotinine do not adjust to this pattern and appear more in some brands than in others.

The results also reveal that the brands with the lowest production of gaseous compounds are not those with the lowest tar levels, and that the brand that generates the most isoprene, toluene and chrotonaldehyde produces a lower quantity of tar than the average. "We should not therefore assume that a cigarette which generates more tars is going to be more toxic than another that produces fewer", notes Beltrán.

The researchers, who claim in the article not to have any conflict of interests, have preferred not to reveal the figures for each brand and have identified these with the letters A to J. To perform the analysis the cigarettes were inhaled in a 'smoking machine' and the smoke composition was measured in three fractions: one gaseous, in which 35 compounds were identified, and two of particulate matter, with 85 compounds, which were trapped respectively in the filter and in the smoke traps used to measure "what a person smokes".