Table 3

Comparison of air nicotine and particulate matter monitoring

 Airborne nicotine (passive or active sampling) Particulate matter (PM) (direct reading or active filter sampling) Timescale Duration of sampling depends on the amount of nicotine in the air and sampling method (active vs passive). Active sampling generally requires several hours where as passive sampling may need 1–2 days to 1–2 weeks. For instance in a bar or nightclub where smoking is allowed 1 day of sampling is generally sufficient to provide a precise quantification of nicotine in that environment. For any location, a week of sampling has the advantage to provide a good estimate of time-weighted average concentrations. Measurements are taken continuously and stored in memory as often as once per second for 6–14 h depending on batteries used. Longer sampling would require plugging in and securing the device. Allows for the examination of changes in secondhand smoke exposure (SHSe) over time. Allows for the measurement of peak concentrations that are not seen with integrated methods. Active filter sampling provides the total mass and can be used to identify specific chemical constituents measured over the sample duration. Sensitivity A sufficient amount of nicotine must be collected on the filter in order to perform quantification in the laboratory. Current laboratory methods are very sensitive allowing for the quantification of ≥0.0026 μg/ml of nicotine. For instance, 1 h of sampling is sufficient to detect an average concentration of 0.22 μg/m3 in an environment where this concentration is constant during the hour of sampling. Nicotine is highly sorbing relative to other SHS compounds. Highly sensitive to tobacco smoke; the machine detects levels as low as 1 μg/m3 of PM while cigarettes emit large quantities of PM, about 14 000 μg per cigarette Specificity Highly specific to tobacco smoke. Tobacco is generally the only source of nicotine. PM is not specific to tobacco smoke and there are many other sources of PM present at all times. Especially at low concentrations it may be difficult to distinguish tobacco smoke PM from other sources. Aerosol-specific calibration required. Correlation between markers Both are correlated with other SHS constituents. Especially in places where there is consistent smoking there is a good correlation between nicotine and PM2.5 with an increase of about 10 μg of PM2.5 for each 1 μg of nicotine. Communication Because there is no safe level of SHSe the concentration of nicotine in the environment should be zero (ie, undetectable). Any level of exposure increases health risk, although the risk is substantially higher with increasing concentrations. Nicotine itself can be of health interest as it may have some cardiovascular effects. Comparisons of air nicotine concentrations in different locations, including smoke-free environments are powerful tools in support of smoke-free initiatives. Difficult to predict health risk associated with levels of nicotine concentrations in the environment. PM2.5 has known direct health effects in terms of morbidity and mortality. There are existing health standards for PM2.5 in outdoor air (USEPA and WHO) that can be used to communicate the relative harm of PM2.5 levels in places with smoking. The continuous nature of sampling allows for the creation of real-time plots showing levels minute-by-minute, which can be powerful communication tools. Cost No expensive equipment to buy up front and minimal operating cost. Per sample laboratory costs including the filter badge are approximately US$40–$100. High initial investment (approximately US\$3000) but minimal operating cost. No per sample costs, that is no laboratory costs or consumables. Potential costs in labour for data reduction and analysis
• Modified from Avila-Tang, 2010.100

• PM, particulate matter; USEPA, United States Environmental Protection Agency.