Data sources Medline, Embase, PsycINFO, ProQuest, Scopus and Web of Science databases were searched up to 6 November 2017 for studies on HnB
published after December 2009; reference lists were screened and other
researchers contacted, yielding 637 records.
Study selection Thirty-one publications on HnB secondhand emissions (n=16) or use by humans (n=15) were selected by two reviewers with
excellent agreement (k=0.75).
Data extraction Data on authors’ affiliations, HnB products, secondhand emissions and human exposure were extracted by one reviewer.
Two reviewers assessed the quality of experimental HnB studies using the
Effective Public Health Practice Project tool.
Data synthesis Twenty out of 31 studies were affiliated with tobacco industry. Studies on secondhand emissions varied by methodology,
products and comparators. Compared with cigarettes, HnB delivered up to
83% of nicotine and reduced levels of harmful and potentially harmful
toxicants by at least 62% and particulate matter by at least 75%.
Experimental HnB use studies were limited to one product, reductions of
human exposure to toxicants varied between 42% and 96%. HnB use
suppressed urges to smoke, but participants rated HnB less satisfying
than cigarettes. While limited by methodological heterogeneity, findings
were largely similar for independent and industry-funded studies.
Conclusions Studies on HnB secondhand emissions and human use were heterogeneous and largely affiliated with the manufacturers. HnB exposed
users and bystanders to toxicants, although at substantially lower
levels than cigarettes.
This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which
permits others to copy, redistribute, remix, transform and build upon
this work for any purpose, provided the original work is properly cited,
a link to the licence is given, and indication of whether changes were
made. See:
