J UOEH 42（ 4 ）: 335−338（2020）

335［Short Report］

Secondhand Smoke from a Veranda Spreading to Neighboring Households
Hiroshi Yamato1*, Takaaki Kato2, Ying Jiang1, Daichi Shimizu2, Ryo Tomonaga1, Toshiki Fujimoto1 andNozomi Yamamoto1
1

Department of Health Development, Institute of Industrial Ecological Sciences, University of Occupational andEnvironmental Health, Japan. Yahatanishi-ku, Kitakyushu 807-8555, Japan2
Department of Life and Environmental Engineering, The University of Kitakyushu. Wakamatsu-ku, Kitakyushu
808-0135, Japan

Abstract : Secondhand smoke (SHS) caused by smoking on apartment verandas is a severe social problem in Japan.
If someone smokes on a veranda, SHS drifts into other residentsʼ rooms through their windows. Most non-smoking
residents are annoyed by this, but they do not confront the person responsible. To study this situation, we burned
cigarettes and measured the spread of SHS in terms of fine particle (PM2.5) concentrations. Cigarette smoke generated on a lower veranda spread to upper and horizontal neighboring verandas and into rooms through windows,
reaching a maximum concentration of 139 μg/m3. The Health Promotion Act that was revised in 2018 and enacted in
2019–2020 requires all smokers to avoid producing SHS, even outdoors and at home. It is expected that combining
the measurement of SHS from verandas to other verandas and rooms with the revised Health Promotion Act could
create a national consensus on “no smoking on apartment verandas.”
Keywords : secondhand smoke, PM2.5, Health Promotion Act, apartment house.
（Received August 4, 2020, accepted September 11, 2020）

Introduction
Tobacco control in Japan is still behind the world
standard in almost all respects, particularly in terms
of protecting non-smokers from secondhand smoke(SHS). The Japanese government revised the Health
Promotion Act in 2018, aiming to eliminate “unwanted” SHS [1]. This Act was enacted in three stages.
First, starting in January 2019, smokers had to beaware of their surroundings when smoking outdoors
and at home. Secondly, starting in July 2019, schools,universities, and government and municipal offices
had to implement a total ban on smoking on the premises (designated outdoor smoking areas/rooms are al-lowed). Thirdly, as of April 2020, smoking became
prohibited inside private businesses, including restaurants and bars (designated smoking rooms are allowed). The countermeasures against SHS in public
places have been gradually improving in Japan.
On the other hand, SHS in private situations is another problem, especially smoking on apartment verandas. Non-smokers who live in apartment houses
complain about the smell of tobacco smoke, but it isdifficult to confront the person responsible becauseof the risk of trouble starting. This problem attractedsocial attention in 2020 because of remote work andthe governmentʼs request that people stay home due toCOVID-19. Smokers started spending longer hours at*Corresponding Author: Hiroshi Yamato, Department of Health Development, Institute of Industrial Ecological Sciences, University of Occupationaland Environmental Health, Japan. Yahatanishi-ku, Kitakyushu 807-8555, Japan, Tel: +81-93-691-7473, Fax: +81-93-602-6395, E-mail: yamato@
med.uoeh-u.ac.jp

H Yamato et al336

home and the consumption of cigarettes on verandas
increased.
We measured the concentration of tobacco smokethat spread from a lower veranda to upper and horizontal neighboring verandas, and to the inside of rooms.
Our purpose was to obtain objective data on SHS
spreading from verandas to other households and explore the likelihood of public opinion shifting to support “no smoking on apartment verandas.”Materials and Methods
Experimental measurement was done using the second and the third floors of a typical 3-floor apartment
house (Figure 1) in October 2015. We used five digital
dust monitors (TSI, Sidepak, AM510). Figure 2 shows
the situation of the measurement in a typical apartment
house in Japan. Five dust monitors were set up, as

②③④⑤

①

Figure 1. External appearance of the apartment and thefive measurement points of fine particulate matter (PM2.5).
Gap↓④⑤④Figure 2. Measurement of PM2.5 on the neighboringveranda and inside the room on the same floor.

follows:① : Veranda where cigarettes were burned② : Veranda of the upper floor③ : Inside of the upper room
④ : Neighboring veranda on the same floor⑤ : Inside of the neighboring room on the same floor
The weather was clear and a weak breeze blew toward the apartment. A total of 5 cigarettes were continuously lit one by one and a side-stream of smoke
was generated by a researcher wearing personal protective equipment. The concentration of fine particulate matter (PM2.5) was simultaneously measured at thefive points.

Results
Before the experiment, the ambient PM2.5 concentration was 7 to 12 μg/m3, which is categorized as “good”
according to the Air Quality Index by the U.S. Environmental Protection Agency [2]. Then, 5 cigarettes
were continuously lit one by one from 9: 55 to 10: 23.
Figure 3A shows the PM2.5 concentrations on the veranda where the cigarettes were burned (dust monitor ①), the veranda on the upper floor (dust monitor②), and inside an upper room (dust monitor ③) with
open windows. PM2.5 spread to the upper veranda,
then inside the room. The peak of PM2.5 was 89 μg/
m3 at 10: 13 on the upper veranda. Every time the authors sensed the smell of cigarette, the concentration of
PM2.5 had increased.
Figure 3B shows the spread of cigarette smoke fromthe veranda where the cigarettes were burned (dustmonitor ①) to the neighboring veranda on the samefloor (dust monitor ④) and inside the room (dust monitor ⑤) with open windows. It was also confirmedthat cigarette smoke spread horizontally with a peakPM2.5 of 139 μg/m3 at 9: 58.

Discussion
The problem of SHS in apartments has been argued
about for decades, especially in developed countries,
prompting some cities to implement smoke-free policies for apartments [2–4]. The same social trend also
appeared in Japan. The health risks of SHS became
common knowledge in the late 1990s. As the HealthSecondhand Smoke Spreading to Neighboring Householdsspreads horizontally to the same floor (Figure 3B).
Verandas of apartments are evacuation passages. The
separation between verandas consists of an easily-broken board so that there is a gap around the board, as
shown in Figure 2. In this study, we considered thatthe cigarette smoke congested in the space of the veranda spread to the neighboring verandas through thegap around the evacuation-board when the weak windblew toward the apartment. The reason for the higher
concentrations inside the room than on the veranda(Figure 3B) could be explained as the smoke spreading through the gap and moving along the wall theninto the room on the weak wind that was blown toward
the apartment.
Recently, some apartment houses have prohibitedsmoking on verandas, but this is rare and most nonsmokers living in apartments still suffer from SHS.
Since January 2019, the revised Health PromotionA

BeforeBurnCigs.

B

Peak: 139μg/m3

Concentration of PM2.5 (μg/m3)

Concentration of PM2.5 (μg/m3)

Promotion Act (2003) required the managers of all
facilities to take effective countermeasures against
SHS, indoor smoking became prohibited in most public places and private offices, except in designatedsmoking rooms. This trend also spread to private
homes. Smokers (mostly husbands) became forced tosmoke outside in order to protect their family members. Many smokers started to smoke on apartment
verandas, and they are sometimes called hotaru-zoku(firefly persons). In this way, veranda smokers cause
trouble for neighboring residents, a problem often appears in the news media. In 2012, the district court ofNagoya made an order of compensation of 50,000 yen(approximately US$ 500) for damages caused by SHS
from the lower floor to upper neighboring residents.
It is easy to understand that cigarette smoke spreads
from the lower veranda to the upper veranda, as shownin Figure 3A, but, importantly, cigarette smoke also

337

BeforeBurnCigs.

Figure 3. A: Spread of cigarette smoke from the veranda where cigarettes were burned to upper veranda and inside theroom. B: Neighbor veranda and inside the room on the same floor. Cigs: cigarettes

H Yamato et al338

Act has required all smokers to reduce SHS, evenoutdoors. Basically, the veranda of an apartment is acommon space for all of the residents of the building,and it is prohibited to do anything that bothers otherresidents. A combination of the revised Health Promotion Act and the objective data in this study may beable to create a national consensus on “no smoking onapartment verandas.”Finally, it is expected that attempts to quit smoking could increase because smokers will not be able tosmoke in public or private places.

Conclusions

this experiment.
The authors deeply appreciate Dr. R. Michishita andstudents of UOEH (Mr. K. Hashimoto, Ms. R. Kakinoki,Ms. N. Oohama, Ms. A. Yamamoto) for their assistancein measuring PM2.5.

References
1 . Ministry of Health, Labour and Welfare (2018): Revised Health Promotion Act https://www.mhlw.go.jp/
english/policy/health-medical/health/dl/201904kenko.
pdf [accessed August 1, 2020]
2 . U.S. Environmental Protection Agency (2012): Revised air quality standards for particle pollution and up-

We measured the spread of SHS in terms of the concentration of PM2.5. Cigarette smoke generated on averanda spread to horizontal and upper neighboringverandas and then to rooms through windows. Apartment verandas are a common space for all of the residents. We should create a national consensus on “nosmoking on apartment verandas.”

Conflicts of Interest

dates to the Air Quality Index (AQI) https://www.epa.
gov/sites/production/files/2016-04/documents/2012_
aqi_factsheet.pdf [accessed August 1, 2020]
3 . Russo ET, Hulse TE, Adamkiewicz G et al (2015): Comparison of indoor air quality in smoke-permitted andsmoke-free multiunit housing: findings from Boston
Housing Authority. Nicotine Tob Res 17(3): 316-322
4 . Anastasiou E, Feinberg A, Tovar A et al (2020): Secondhand smoke exposure in public and private highrise multiunit housing serving low-income residents inThe authors declare no conflicts of interest.

Acknowledgements

New York City prior to federal smoking ban in public
housing, 2018. Sci Total Environ 704: 135322
5 . Levy DE, Rigotti NA, Winickoff JP (2013): Tobaccosmoke exposure in a sample of Boston public housing

This work was supported by MHLW Program Grant
Number 19FA1006. The University of Kitakyushu
granted the authors the use of the apartment rooms forresidents. Am J Prev Med 44(1): 63-66

J UOEH42（4）：335 − 338（2020）