The lead levels in mainstream smoke generated under ISO and HCI machine-smoking regimes are consistent with results obtained from smaller datasets [30], [46], [48], [61], [62], [64] and [66] and GSI-IX narrower than the range of historical results provided in an early review [65]. If adjusted for nicotine yields, the range and median values for lead yields are very similar

under both regimes, suggesting that, in contrast to cadmium yields, lead yields behave in the same way as nicotine when machine-smoking conditions are changed. The arsenic levels in mainstream smoke (for the samples above LOQ) are slightly higher than previously reported for UK brands [62], or international brands from Philip Morris [61], while their distribution is clearly narrower than the span of historical data gathered in an earlier review in which levels up to 1400 ng/cigarette had been reported [65]. Even after nicotine normalization, the range of elements yields was wide, which was a consequence of the spread

of the elements levels in tobacco. Of particular interest in the market surveys data is the fact that, at equal nicotine transfer, the cadmium transfer in a sample containing activated carbon in the this website filter is much smaller than that of a sample without carbon in the filter. No such trend could be observed in the data regarding either lead or arsenic. This is readily apparent by visually comparing

SDHB Fig. 1 and Fig. 4 – showing cadmium transfer against nicotine transfer, to the similar plots obtained for lead and arsenic, or by directly comparing cadmium and lead transfers among all samples in Fig. 7 and Fig. 8. This effect can be quantified using the slopes of the regression lines reported in Table 6. Considering the ratio of slopes as the ratio of averaged yields of samples with equal nicotine transfer, the results correspond to cadmium yields reductions in the presence of activated carbon amounting to 57% in smoke generated under the ISO machine-smoking regime and 34% under the HCI machine-smoking regime. Direct comparison of cadmium and lead transfers (Table 7) shows that for smoke generated under the ISO regime cadmium transfer is about 22% lower than that of lead. It is 15% lower under the HCI regime; the more intense puffing and the suppression of the filter ventilation weaken the efficiency of cadmium filtration. As expected, in the presence of activated carbon this difference is substantially increased. The present results are in agreement with those reported in the survey of the Japanese market [63]. The mainstream smoke yields of cadmium, lead and arsenic from cigarettes with a very high load of activated carbon (80 mg) in the filter were compared to those of the matched control.