Using MTurk convenience samples can yield generalizable findings for experiments and observational studies. Prevalence estimates from MTurk convenience samples are likely to be over- or underestimates.

Introduction The Tobacco Control Act requires public disclosure of information about toxic constituents in cigarette smoke. To inform these efforts, we studied public understanding of cigarette smoke constituents. Methods We conducted phone surveys with national probability samples of adolescents (n=1125) and adults (n=5014) and an internet survey with a convenience sample of adults (n=4137), all in the USA. We assessed understanding of cigarette smoke constituents in general and of 24 specific constituents. Results Respondents commonly and incorrectly believed that harmful chemicals in cigarette smoke mostly originate in additives introduced by cigarette manufacturers (43–72%). Almost all participants had heard that nicotine is in cigarette smoke, and many had also heard about carbon monoxide, ammonia, arsenic and formaldehyde. Less than one-quarter had heard of most other listed constituents being in cigarette smoke. Constituents most likely to discourage respondents from wanting to smoke were ammonia, arsenic, formaldehyde, hydrogen cyanide, lead and uranium. Respondents more often reported being discouraged by constituents that they had heard are in cigarette smoke (all p<0.05). Constituents with names that started with a number or ended in ‘ene’ or ‘ine’ were less likely to discourage people from wanting to smoke (all p<0.05). Discussion Many people were unaware that burning the cigarette is the primary source of toxic constituents in cigarette smoke. Constituents that may most discourage cigarette smoking have familiar names, like arsenic and formaldehyde and do not start with a number or end in ene/ine. Our findings may help campaign designers develop constituent messages that discourage smoking.

Introduction: Understanding what people think about harmful and potentially harmful constituents in cigarettes and cigarette smoke has new urgency given legislation requiring US Food and Drug Administration (FDA) to disclose constituent information. Our study sought to obtain qualitative information on what people think about these constituents and the language they use to talk about them. Methods: We conducted six focus groups in 2014 with 40 adults in North Carolina. Open-ended questions focused on cigarette and cigarette smoke constituents in general and on the 18 constituents on the FDA's abbreviated list. We coded the transcripts for emergent themes, and all four coders discussed themes until we reached consensus. Results: Participants knew that cigarette smoke contains chemicals but did not know how many chemicals nor what those chemicals are, beyond tar and nicotine. Dangers of constituents mentioned included "chemicals, " physical disease, and addiction. Participants incorrectly believed harmful constituents came primarily from tobacco companies' additives. For unfamiliar constituents, people tried to make associations based on similar-sounding words. Recognizable constituents that participants associated with health harms most discouraged them from wanting to smoke. Most participants wanted to know health harms associated with constituents and what else the chemicals were in. Conclusions: Participants showed enthusiasm for learning more information about constituents, and also showed substantial misunderstandings about the source of harmful constituents. Our findings contribute to the limited body of research on adults' knowledge and perceptions of cigarette smoke constituents and can aid the FDA as it plans to disclose constituent information to the public. Implications: Our study provides information about adults' understanding of cigarette smoke constituents and what adults would like to know about these constituents. This information can help communication campaigns describe cigarette smoke constituents in a way that discourages people from wanting to smoke.

Laws and treaties compel countries to inform the public about harmful chemicals (constituents) in cigarette smoke. To encourage relevant research by behavioral scientists, we provide a primer on cigarette smoke toxicology and summarize research on how the public thinks about cigarette smoke chemicals. We systematically searched PubMed in July 2016 and reviewed citations from included articles. Four central findings emerged across 46 articles that met inclusion criteria. First, people were familiar with very few chemicals in cigarette smoke. Second, people knew little about cigarette additives, assumed harmful chemicals are added during manufacturing, and perceived cigarettes without additives to be less harmful. Third, people wanted more information about constituents. Finally, well-presented chemical information increased knowledge and awareness and may change behavior. This research area is in urgent need of behavioral science. Future research should investigate whether educating the public about these chemicals increases risk perceptions and quitting.

NCT02785484.