Dr N J Masters and Catherine Tutt
The smoking load calculator has used readily derived conversion figures which have been taught at the National Respiratory Training Centre at Warwick, England over the last seventeen years. This is not an exact science and approximations have been made, for example a cigarillo is 2 cigarettes and a cigar is 4 cigarettes. Loose tobacco estimates that 25 grams (1 oz) has been approximated to be the equivalent of 50 cigarettes. One pipe is equivalent to 2½ cigarettes. The original work from which these figures were obtained could not be found by the present authors. Nevertheless as large numbers of practice nurses had been trained using these apparently unreferenced figures, it was decided by the authors to continue to use this data in the world’s first pack year calculator.
Other references that have been used are listed below:
References 3 and 4 were used to check that our approximated unreferenced figures were close to others working in this area.