Acrylamide levels in smoke from conventional cigarettes and heated tobacco products and exposure assessment in habitual smokers

Acrylamide (AA) is a neurotoxic, genotoxic, and carcinogenic compound developed during heating at high temperatures. Foods such as potatoes, biscuits, bread and coffee are the main foodstuffs containing AA. Cigarette smoke may be a significant additional source of exposure. However, AA content may vary among different types of cigarettes. The study aimed to evaluate the AA content in conventional cigarettes (CC) and heated tobacco products (HTP) and its resulting exposure through their use. AA levels from the two types of cigarettes were determined by GC-MS and the daily exposure to AA was also ascertained. The margin of exposure (MOE) was calculated for neurotoxic and carcinogenic risk based on benchmark dose lower confidence limit for a 10% response (BMDL10) of 0.43 and 0.17, 0.30, and 1.13 mg/kgbw/day. AA level in CC ranged from 235 to 897 ng/cigarette, whereas HTP reported AA levels in the range of 99–187 ng/cigarette. The data showed a low neurotoxic risk for either CC or HTP, whereas a carcinogenic risk emerged through the smoking of CC based on different Benchmark doses. The carcinogenic risk for CC based on the highest Benchmark dose that was considered showed unsafe levels, as little as 10 CC cigarettes/day, whereas it was almost always of low concern for HTP. Another approach based upon the incremental lifetime cancer risk (ILCR) analysis led to similar results, exceeding, in some cases, the safety value of 10−4, as far as CC are concerned. Overall, the results confirmed that CC are a significant source of AA, and its levels were five times higher than in HTP.