Methodology
To identify optimum scientific criteria for additive testing, the investigators compared conventional toxicological and regulatory approaches to epidemiological studies. LSRO could not find toxicological tests that predicted the full range of adverse human health effects. Of particular concern was the difficulty in determining "safe" levels of additives in the context of the obviously unsafe act of smoking. To overcome these problems, LSRO adopted a relative risk approach. Investigators could compare cigarettes containing an ingredient to otherwise identical cigarettes lacking the same ingredient. This approach allows researchers to factor out the adverse health effects, revealing the effects of the additive, if any. This approach focuses on inhalation testing within a smoke matrix, instead of ingestion testing of purified additives.
Findings
The researchers concluded that this approach could establish whether:
(1) the additive, or a pyrolysis product of the additive, did not detectably transfer into cigarette smoke in such a way that smokers might be subject to a change in risk;
(2) the additive did not significantly change the chemistry, physics or biological properties of smoke; and
(3) the additive did not change exposure to cigarette smoke through altered smoking behavior.
If the additive met these three criteria, the expert panel concluded that they would not anticipate that use of the ingredient would increase adverse human health effects. If the additive did not meet one of the criteria, the panel recommended further testing. This could include reducing the amount of ingredient added and retesting or obtaining additional data demonstrating no change in the relative risk of adverse human health effects. The report gives examples.
Conclusions
The purpose of the report was not to c
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27-Dec-2004