Potential impact of partial and total filter ventilation blocking on cigarette mainstream emissions during smoking
Cigarette mainstream smoke yields are broadly proportional to the quantity of tobacco burned during puffs. A mathematical model was developed to calculate this quantity during smoking, taking into account the tobacco burning rates during and between puffs, the burning rates between and on LIP bands, the puffing conditions (puff and inter-puff interval durations, puff volume), filter and paper ventilations, LIP band positions and the probability of extinguishment on each band.
The model was used to assess the impact of partial and total filter ventilation blocking on the exposure of a virtual population of cigarette consumers. A range of smoking conditions were considered with puff durations ranging from 1 to 3 seconds, puff interval from 30 to 90 seconds and puff volume from 20 to 70 millilitres.
For a given product design, calculations show a wide range of estimates for tobacco actively burnt resulting from the different puffing behaviours within a population of smokers. When the extent of blocked filter ventilation increases, the distribution of tobacco actively smoked moves to upper levels assuming the range of smoking behaviour is unchanged. This means that regular smokers of ventilated products could potentially be exposed to higher mainstream smoke yields if 100% of the ventilation holes were blocked.
These findings suggest that a filter ventilation ban should not be considered without a careful evaluation of the potential unintended consequences. In particular studies designed to understand the impact for regular consumers of filter ventilated product switching to non-ventilated products would be required.