Which smoking-related biomarker remains elevated for weeks after smoking but does not indicate low-level smoking accurately?

Thiocyanate is a smoking-related biomarker that remains elevated for an extended period after smoking has ceased. Unlike other biomarkers, thiocyanate is not a direct product of nicotine metabolism but is derived from the interaction of cyanide, which is found in tobacco smoke, with other substances in the body. This characteristic allows thiocyanate levels to linger in the bloodstream, often for weeks following smoking cessation.

While it is detectable for a prolonged period, thiocyanate is not very effective at differentiating between low-level smoking and non-smoking status. Hence, it lacks sensitivity as an indicator in cases of intermittent or light smoking. In contrast, biomarkers like cotinine, which is a metabolite of nicotine, can provide more immediate insight into recent smoking behavior but may not have the same prolonged persistency in the absence of further nicotine exposure.

Carboxyhemoglobin, a form of hemoglobin bound to carbon monoxide, is another useful biomarker but tends to decrease relatively quickly after the cessation of smoking. Anabasine, a tobacco alkaloid, does not hold the same significance as thiocyanate when considering its persistence and utility in determining low-level smoking status. This specific profile of thiocyanate makes it unique