Nonsmokers’ Bodies Held to Retain Toxins Twice as Long as Smokers’

People sitting in a room filled with cigarette smoke retain the dangerous chemicals they inhale more than twice as long as people doing the smoking, researchers said Thursday.

The finding could mean that nonsmokers are at greater risk from ambient smoke than previously thought, but “we really have to take a closer look before we can say that,” said Daniel Sepkovic, a clinical biochemist with the Naylor Institute of Disease Prevention in Valhalla, N.Y.

But nonsmokers still are in far less danger than the smokers themselves, Sepkovic said.

Dilution Factor Cited

“Even though there is an increased (toxin) retention time in the nonsmoker, you have to take into account the tremendous dilution factor,” he said. “It’s on the order of 10 to 100 times smaller than for smokers.”

Sepkovic and his colleagues, in a letter to the Journal of the American Medical Assn., said they recruited 10 smokers and four nonsmokers to find how long their bodies retain cotinine, an end product in the metabolism of nicotine.

Cotinine levels were measured over a four-day period for smokers and for nonsmokers exposed to a smoky environment for 160 minutes every day. At the end of the period, the smokers quit smoking.

Eliminating Cotinine

Although the initial cotinine levels were more than 100 times greater for the smokers than for the “passive smokers,” it took the passive smokers more than twice as long to eliminate the cotinine from their blood as smokers--49.7 hours for the passive smokers compared to 18.5 hours for the smokers.

Sepkovic said he has “a couple of speculative kind of hypotheses” as to why this phenomenon occurs, most of them based on the presumption that the bodies of smokers are more conditioned to eliminate cigarette toxins.