The May 3, 2011 edition of Chemistry World carried an interesting article by James Urqhart — Titanate cigarette filter — regarding several Chinese researchers who have developed a cigarette filter which employs nanoscale TiO2 which supposedly filters out harmful tobacco smoke constituents.  One of the researchers claims that "[a] great range of harmful compounds including tar, nicotine, ammonia, hydrogen cyanide, selected carbonyls and phenolic compounds can be reduced efficiently." 

The article also maintains that the researchers are "confident that titanate nanomaterials used in filters do not pose a health risk to smokers by inhalation" because "TiO2 is already widely used in consumer products including sunscreens, cosmetics and food."  Readers can judge the strength or weakness of this logic for themselves.

The article draws to mind Kent cigarettes with Micronite filters which were manufactured in the early to mid 1950s.  Believe it or not, these particular Kent cigarettes utilized crocidolite asbestos in their filters because of its unique filtering properties.  Readers can imagine the health-related lawsuits and judgments that followed.

Despite their unique filtering properties, mixing tobacco and engineered nanoscale materials in cigarette in this litigation environment is probably a bad idea.