Japan's Ministry of Health, Labour and Welfare announced Thursday that no strong association has been found between second-hand smoke from heated tobacco products and health risks [1].
This finding is significant as it addresses the safety of heated tobacco products, which have seen widespread adoption as alternatives to traditional cigarettes. The assessment influences public health guidelines and potential regulations regarding indoor smoking in Japan.
The ministry said that at this time, the relationship between second-hand smoke and health effects is not recognized as being strong [2]. However, the report noted that some carcinogens are detected in the side-stream smoke, and harmful chemical substances spread through the air when these products are used indoors [3].
Officials said the lack of a definitive causal link is due to a shortage of available research. Because heated tobacco products have not been on the market long enough to provide extensive long-term data, experts emphasized the need for continued study [4].
"Heated tobacco products have not been in widespread use for a sufficient number of years, and it is necessary to continue research on their effects on health," a ministry committee expert said [4].
The ministry's evaluation suggests that while the emission of harmful substances may be lower than that of traditional combustible cigarettes, the current evidence base is too thin to rule out risks or confirm safety [2], [3].
“"At this time, the relationship between second-hand smoke and health effects is not recognized as being strong."”
This assessment highlights a critical gap in longitudinal public health data for newer tobacco technologies. By acknowledging that carcinogens are present but causal links are unproven, the Japanese government maintains a cautious middle ground—avoiding a definitive 'safe' label while lacking the evidence required to implement stricter bans specifically targeting heated tobacco second-hand smoke.
