Today the indoor air quality is considered one of the main concerns of many international institutions related to environmental and health issues and polluted air is considered dangerous for human health. WHO (World Health Organization) has estimated that approximately 3.8 million people die every year prematurely from illness attributable to household air pollution [1]. Science and technology are combined together to create innovative smoking techniques in order to reduce the harm of smoking. As a result, Heat Not Burn revolutionary technology is introduced. This review study is focused on evaluating the smoking effects on indoor air quality comparing traditional smoking with new technologies and smoking techniques. Actually, the use of new techniques such as THS (Tobacco Heating System) or electronic device IQOS (I Quit Ordinary Smoking) has lower pollution effects compared to the traditional type of smoking. The use of new techniques results in the lowest concentrations of formaldehyde, benzene, toluene, PM2.5, among the majority researched pollution sources. So, this paper is based on a literature review approach analyzing the newest debates on the topic with the aim to give conclusion and recommendations on the long-term period on the use of new smoking technologies and future expectations.
Today more and more people are being
sensitive to health problems in general and they
caused by smoking. Many efforts are made to
reduce the harm of smoking. Heat Not Burn
technology is one of the results of these efforts
and researches. People in developed and
developing countries spent the majority of their
living time indoors. [
Under this optic, it is important to understand which are the tobacco types that have negative effects in indoor areas. This paper is based on a literature review approach.
According to WHO 2000 [
This paper was focused on reviewing
several scientific articles and conference papers
on the main effects in indoor air quality
smoking and to direct future research in this
field. This review permitted to make a
comparative analysis on different scientists’
opinions and research on indoor smoking
effects. So, the analysis was focused on a
systematic review of published papers on
indoor smoking. “A systematic review attempts
to collate all empirical evidence that fits the
pre-specified eligibility criteria in order to
answer a specific research question. It uses
explicit, systematic methods that are selected
with a view to minimizing bias, thus providing
more reliable findings from which conclusions
can be drawn and decisions made”[
The first step of the analysis was the paper’s
identification [
As well it was eliminated duplicate titles, and titles which were clearly not related to our scope. The selected papers were 19 out of 57 relevant studies, which were considered the most appropriated corresponding to the goal of the paper.
The tobacco industry’s most recent response to the documented harms of cigarette smoking was to launch new heat-not-burn (HNB) tobacco cigarettes [9]. Heat Not Burn technology is the answer of many researches and efforts to reduce the harm of smoking. One of the electronic devices that use heat not burn revolutionary technology is IQOS (I Quit Ordinary Smoking). The Heat Stick that contains the tobacco, a holder and a charger are parts of the IQOS. Tobacco Heating System IQOS heats tobacco and not burn it compared to traditional cigarettes.
For many years indoor smoking cigarettes was not considered a major problem and only after 2007 EU adopted a Recommendation on Smoke-free Environments "provide effective protection from exposure to tobacco smoke in indoor workplaces, indoor public places, public transport and, as appropriate, other public places”[10].
A major source of indoor air pollution is considered second-hand smoke [11]. Normally, the smoking of tobacco products (especially second-hand tobacco) leads to a massive increase of particular matter (PM) in enclosed spaces [12]. Studies has demonstrated that long-term exposure to PM correlates with cardio-vascular and respiratory diseases, lung cancer, and cardiopulmonary mortality [13]
But, it is observed that environmental tobacco smoke (ETS) is one of the many sources of airborne PM in the indoor environment [14]. On the other hand, ETS is a combination of exhaled mainstream smoke (MS) and side stream smoke (SS) released from the smoldering tobacco product, and a complex mixture of chemical constituents that remains in surfaces fixed in building materials, carpets, upholstery, and furniture (third-hand smoke). [11],[15].
Indoor pollutants mainly contain organic or
inorganic chemicals, biological aerosols
(bioaerosols), and particles but the list is a wide
range [
On the other hand, we have to analyze smoking indoor effects of the new smoking technologies such as the Tobacco Heating System (THS).
Use of THS was reported not to increase indoor concentrations of carbon monoxide and nitrogen oxides [17], which are listed as WHO priority pollutants. Generally, the usage of THS has been associated with lower or comparable indoor air pollutant concentrations compared against other conventional indoor sources or environments, in most cases distinguishable above background, thus potentially being associated with health effects at prolonged exposure as any other artificial air pollution source [16].
On the other hand [18] found that IQOS have an impact on airways function, exhaled CO, and SaO2% of both smokers and nonsmokers immediately after use, but at the same time they admit their effects on pulmonary function, short- and long-term, have not been adequately studied yet.
[19] studied that the levels of pollutants
emitted by e-cigarettes and HNBT are
substantially lower compared to those from
TCs, the new smoking devices are still a source
of indoor air pollutants. As well the nicotine
yield is comparable to typical combustible
cigarettes and observe substantially reduced
levels of aldehydes (approximately 80–95%)
and VOCs (approximately 97–99%) [
On the other hand, according to [20] iQOS emissions seem to be fairly clean in terms of metal emissions compared to both Conventional Cigarettes and Electronic Cigarettes. So, the concentration levels of hazardous compounds in the mainstream smoke of iQOS are much lower than those in conventional combustion cigarettes [21].
Recent studies are confirming that iQOS have a significantly lower burden of emissions for all classes of PM, including total PM emissions (all p < 0.05) [22], or at least modified risk in indoor smoking [23].
Results for tar and nicotine yield released from THS 2.2 has shown similar results with Conventional Cigarette, but there is found more water in THS 2.2. There are some reasons for presence of higher water in THS 2.2 compared to Conventional Cigarettes, and one of the is linked with due to the additional of glycerol and propylene glycol in the THS 2.2 heating sticks. Although most mainstream constituents of THS 2.2 are reduced compared to Conventional Cigarettes standards or 3R4F. Regulators have to pay more attention of smoking topography as a smoking machine according to the HCI-toISO ratio [24].
It is very important to continuously monitor indoor air quality as the negative effects of smoking using Heat Not Burn technology and the impact on indoor environments have not yet been studied at an adequate level. Real-time monitoring of indoor air quality can reveal harmful health situations that can be resolved with human intervention. Many studies, have been conceived or designed sensor-based networks to monitor indoor air quality in real time [25, 26, 27, 28, 29]. Advances in networking, sensors, and embedded devices have made monitoring and supply of assistance possible to people in their homes [27], but not only. Based on the systematic review for indoor air quality monitoring systems based on internet of things [30] the general architecture of IoT based monitoring system presented in figure 1 provide real time monitoring of indoor air quality.
Further studies will be needed to find the best solution in terms of cost and real time monitoring of indoor air quality when people smoke with devices that use Heat Not Burn technology.
Tobacco smoke and THS are considered as artificial air pollution source in indoor areas. Several studies admit that the use of THS produce insignificant emissions of hazardous compound in indoor smoking. THS technology has contributed to reduce the level of the indoor smoking pollutants.
Long term health effects by THS indoor smoking have not been studied properly. On the other hand, the negative effects of THS and the impact on indoor smoking is not studied yet in an adequate level.
The toxic compounds (nicotine tar and tobacco specific nitrosamines) are not completely removed from the mainstream smoke of iQOS, making it necessary to consider the health effects and regulation of second-hand smoke widely recognized as a common issue by WHO [31].
On the other hand, scientists are suggesting that it is better to enable a smoke free environment to avoid the differences between main and passive smokers and as well to protect human health even the negative effects of heatnot-burn tobacco are not yet verified [32].
[10] [11] [12] [13] [14] [15] [18] [19] [20] [21] [22]
Bekki K., Inaba Y., Uchiyama Sh. Kunugita N., Comparison of Chemicals in Mainstream Smoke in Heat-not-burn Tobacco and Combustion Cigarettes. J UOEH 39 (3): 201-207 (2017)
M. AL-Harbi. Impact of tobacco smoke on the elemental composition of indoor different particles sizes. International Journal of Environmental Science and Technology (2018) https://doi.org/10.1007/s13762-0181973-7