Many people understand chemicals as entities that do not occur naturally, and which are also invariably toxic. Tobacco control messages liberally use the term ‘chemicals’ to evoke these meanings and create concern among smokers. This may reinforce misunderstandings, potentially leading to smokers making harmful choices. To investigate smokers’ understandings of chemicals, we conducted qualitative research using 18 individual interviews and three focus groups with Australian smokers and recently quit smokers. The research was guided by the ‘mental models’ framework and the recently developed Context, Executive, and Operational Systems theory. We discerned two clusters of mental models: the first cluster focused on combustion as the overarching cause of harm (and were largely consistent with the science) and the second cluster focused on additives as causes of harm. We found most participants displayed limited knowledge of the causes of harm from smoking and some held mutually incompatible beliefs. Most participants believed that cigarettes differ significantly in harmfulness according to whether or not they were believed to contain additives. Only a minority understood that the bulk of the toxicants to which smokers are exposed are combustion products. These findings are directly relevant to tobacco control but also have broader relevance to risk communications about toxic exposures.

许多人将化学物质理解为非自然存在的实体，而且总是有毒的。烟草控制信息大量使用“化学品”一词来唤起这些含义并引起吸烟者的关注。这可能会加剧误解，可能导致吸烟者做出有害的选择。为了调查吸烟者对化学品的理解，我们对 18 名个人访谈和三个针对澳大利亚吸烟者和最近戒烟者的焦点小组进行了定性研究。该研究以“心智模型”框架和最近发展的情境、执行和操作系统理论为指导。我们发现了两组心理模型：第一组关注燃烧作为造成伤害的首要原因（并且在很大程度上与科学一致），第二组关注添加剂作为伤害原因。我们发现大多数参与者对吸烟危害的原因了解有限，有些人持有相互矛盾的信念。大多数参与者认为，根据是否含有添加剂，香烟的危害性存在显着差异。只有少数人知道吸烟者接触到的大部分有毒物质都是燃烧产物。这些发现与烟草控制直接相关，但也与有毒物质暴露的风险沟通具有更广泛的相关性。