Heated tobacco products: Potentials of harm reduction, improvement of indoor air quality and the need for further studies

Air pollution is a major concern in the Philippines, with indoor and outdoor air pollution among the highest causes of mortality in the country. However, the latest regulations deal only with ambient outdoor air pollution. Indoor air pollution is seldom monitored or studied. Most of the official government monitoring data also deal with outdoor air pollution even if Filipinos spend more than 80% of their time indoors. Smoking indoors can be a cause of excess air pollutants in the indoor setting. Heated Tobacco products, newly introduced in the country, have been reported to reduce the harm of exposure to users to air pollutants. We investigated this through the review of 282 studies, research papers, books, and narratives about HTP use and their effects. These studies show reduced release of harmful and potentially harmful compounds (HPHC) in the aerosol and lower concentrations of HPHCs in the indoor environment when using HTPs as compared to tobacco smoke. Short term pre-clinical studies also show a reduction in the biomarkers for potential exposure to these HPHCs and risk calculations have shown a reduction in cancer potencies across populations. While long-term epidemiological studies are still required to determine with finality the risks that HTP use may have, there is already wide agreement in the initial results that the complete switch to HTP use from cigarette smoking presents less risks of harm. The review, however, shows that much has to be studied about the manner by which HTPs can affect indoor air quality in tropical countries such as the Philippines.