Research progress on puffing behaviors of e-cigarette users

Published research methods, results, and potential influence factors of puffing parameters of e-cigarette users were reviewed. At present, the reported literature showed that the puffing parameters of e-cigarette users correlated to a variety of factors, including puffing experience, product types, nicotine concentrations in e-liquids, usage environment, atomizer power, flavor types of e-liquids, solvent or aerosol agents, etc. However, the number of existing studies was limited, and there were great differences among the results of the different studies. Considering the need for suitable regulation of e-cigarettes and the risk assessment of potential harmful component exposure of their users and bystanders in the future, the research on puffing behaviors with a large-scale, better controlled volunteers under natural puffing environment and other defined factors, especially product design variables (including battery capacity, ventilation setting, liquid composition, etc.), influencing puffing parameters, still need to be further studied.