A portable device to measure puffing behaviour and tobacco smoke exposure

Abstract

Standardised machine methods to measure cigarettes have been developed to routinely measure cigarette smoke yields (ISO 3308:2000). While this methodology allows products to be compared it is not indicative of how smokers use a product. Therefore, to provide more accurate measurements of the levels of smoke to which smokers are exposed, it is necessary to measure their puffing behaviour (topography). Since 2002, British American Tobacco (BAT) has used the Smoking Analyser 7 (SA7, BAT/C-Matic Systems) to measure a smoker’s puffing topography and optical tar in real time. Optical tar is an estimate of Nicotine Free Dry Particulate Matter (NFDPM) or tar, based on light obscuration from the smoke aerosol. The SA7 can only be used in a central location, due to its need for a trained operator. Under these conditions smokers’ behaviour may be altered. We have therefore developed a portable, handheld version named the Portable Smoking Analyser (PSA). This records puffing behaviour (flow, volume, duration and interval), by measuring the pressure drop across the device, and optical tar per puff, again by light obscuration, against a gravimetric calibration. The PSA was tested using a two stage approach; the first stage evaluated the accuracy and precision of the PSA in recording machine-generated flow rates and volumes, while the second stage used pre-recorded human puffing profiles. During stage one, a series of flow rates were drawn through the PSA using a Smoking Cycle Simulator (Cambustion, Cambridge UK) with a mass flow meter (TSI, High Wycombe UK) in-line to record the flow rate generated. Figure 1 shows a comparison of the flow rates recorded by the PSA compared to the mass flow meter.