Impact of Japan’s indoor smoke-free laws on the prevalence of smoke-free establishments

A multi-institutional research team in Japan evaluated the impact of the Revised Health Promotion Law and related local ordinances on indoor smoking policies in restaurants and bars. Their analysis identified a modest but significant increase in the proportion of smoke-free establishments following the full enforcement of the national indoor smoking ban in April 2020. Additional increases were observed in jurisdictions covered by stronger passive smoking prevention ordinances implemented by the Tokyo Metropolitan Government and Chiba City. The research is published in the journal Public Health.

To reduce the adverse health effects associated with exposure to secondhand smoke, Japan fully enforced the Revised Health Promotion Law in April 2020, introducing a nationwide indoor smoking ban in restaurants and similar hospitality establishments. However, the law includes temporary exemptions that permit preexisting small-scale restaurants and bars to allow indoor smoking, provided that individuals under the age of 20 are not exposed.

To mitigate the potential public health impact of these exemptions, the Tokyo Metropolitan Government and Chiba City simultaneously implemented stricter passive smoking prevention ordinances designed to further promote smoke-free environments. Therefore, the research team assessed the effects of both the national legislation and local ordinances using data obtained from a major online restaurant review platform covering the period 2016–2022.

The researchers estimated that the proportion of smoke-free establishments nationwide increased by 5.7% points immediately after the enforcement of the Revised Health Promotion Law, compared with the period immediately preceding its implementation. In areas governed by the Tokyo Metropolitan Government and Chiba City, where additional passive smoking prevention ordinances were concurrently enforced, the proportion of smoke-free establishments was estimated to have increased by 13.5% points. Of this increase, 7.8% points were specifically attributable to the local ordinances. As of December 2022, the estimated proportions of smoke-free establishments were 68.3% for restaurants, 70.2% for cafés, 32.8% for izakaya (Japanese-style pubs), and 25.0% for bars.

This study demonstrates that the implementation of the national law and complementary local ordinances was associated with a modest increase in the proportion of smoke-free establishments. However, the findings also indicate that a substantial number of establishments continue to permit indoor smoking, largely because of the exemptions allowed under the current legislation. To further reduce opportunities for exposure to secondhand smoke, the researchers emphasize the importance of eliminating existing exemptions and strengthening the enforcement of current smoke-free regulations.