Table 1.
Articles obtained from the literature search
| Lead author | Year | Country | Type and number of subjects (or target places) | Study design | Outcomes measured | Summary | Main findings | Exclusion of other sources of second-hand smoke |
|---|---|---|---|---|---|---|---|---|
| Cobb et al15 | 2013 | USA | 28 venues in Virginia (17 waterpipe cafes, 5 restaurants permitting cigarette smoking and 6 smoke-free restaurants (5 with valid data)) | Observational | PM with a 2.5 μm aerodynamic diameter or smaller (PM2.5) | Waterpipe café smoking rooms have a hazardous level of PM2.5 that could be potentially harmful to customers and workers | PM2.5 was greater in waterpipe café smoking rooms (374 μg/m3, n=17) compared with waterpipe café non-smoking rooms, cigarette smoking-permitted restaurant smoking rooms, cigarette smoking-permitted restaurant non-smoking rooms, and smoke-free restaurants | Measurements began 5 min prior to entering the venue and ended 5 min after exiting each venue to compare outdoor ambient air to the air inside the venue |
| Daher et al7 | 2010 | Lebanon | 4 repeated waterpipe-smoking sessions and 4 repeated cigarette trials | Observational | Sidestream smoke from waterpipes or cigarettes for ultrafine particles, carcinogenic polyaromatic hydrocarbons, volatile aldehydes, and CO | Second-hand waterpipe smoke emits significant harmful substances | Sidestream waterpipe smoke had nearly 4 times the carcinogenic PAH, 4 times the volatile aldehydes and 30 times the CO of 1 cigarette | Smoking-machine and environmental chamber approach allowed for repeated measurements under controlled conditions and few confounding variables |
| Fiala et al14 | 2012 | USA | 10 indoor hookah lounges in Oregon | Observational | PM smaller than 2.5 μm in diameter | Air quality in hookah lounges in Oregon ranges from unhealthy to hazardous | 2 hookah lounges had peak PM2.5 measurements in the hazardous EPI air quality category, 4 were very unhealthy, and 4 were unhealthy. None had good air quality | Measurements began prior to entering the venues and ended after exiting the venues to compare the outdoor ambient air to the air in the hookah lounges |
| Fini et al12 | 2013 | Iran | 387 total persons (172 male and 215 female) | Observational | Demographic characteristics and questions related to environmental tobacco smoke exposure | A large proportion of citizens of Bandar Abbas city are exposed to environmental tobacco smoke | The most common places that people were exposed to hookah smoke were in the home (93.4%), coffee shops (17.1%) and restaurants (11.5%). People were exposed to environmental cigarette smoke in public vehicles (52.2%) and the home (31.3%) | NA |
| Hammal et al19 | 2013 | Canada | 3 replicates of each of the 3 brands were analysed. 6 randomly selected waterpipe cafes were visited | Observational | Chemical constituents of tobacco-free products used in waterpipes, waterpipe emission under controlled conditions, and air quality markers in waterpipe cafes | Second-hand smoke from herbal shisha contains carcinogens equal to or greater than that found in cigarettes and may be hazardous | Second-hand waterpipe smoke had significant levels of aromatic hydrocarbons, CO, PM2.5 and trace metals | Measurements taken outdoors before and after the visit for comparison |
| Kassem et al21 | 2014 | USA | 24 homes were visited 3 times during a 7-day period | Observational | Levels of indoor air and surface nicotine, child uptake of nicotine, the carcinogen NNK, and the toxicant acrolein by measuring corresponding metabolites cotinine, NNAL and NNAL-glucuronides and 3-HPMA | Children living in homes of hookah smokers are exposed to nicotine, the carcinogen NNK and the toxicant acrolein, which pose a threat to long-term health | Compared with homes of non-smokers, children living in homes of daily or weekly/monthly hookah smokers had significantly elevated levels of cotinine and NNAL, with children of daily smokers also having significantly elevated 3-HPMA | 2 air samples were collected with passive diffusion monitor badges in the living room and child's bedroom. A blank non-analysed badge was placed in a third room |
| Markowicz et al18 | 2014 | Sweden | Filters from 10 replicate sessions of waterpipe smoking | Observational | Microbial compounds in waterpipe smoke | Waterpipe smoke creates a bioaerosol similarly to cigarette smoke | In a 1–2 h session, second-hand smoke from waterpipes produced a concentration of 2.8 pmol/m3 of LPS. Ergosterol was not detected. This is comparable to 22.2 pmol/m3 of LPS and 87.5 ng/m3 of ergosterol from smoking 5 cigarettes | NA |
| Tamim et al22 | 2003 | Lebanon | 625 students from 5 different private schools | Observational | Information on demographic, in-home smoking, and students’ respiratory tract illnesses (cough, wheezing, runny nose, or nasal congestion) | Children exposed to second-hand waterpipe smoke may develop respiratory problems | 22.6% (12/53) had wheezing or nasal congestion, 11.3% (6/53) had just wheezing, and 15.1% (8/53) had just nasal congestion | NA |
| Zaidi et al17 | 2011 | Pakistan | 39 indoor venues (13 shisha smoking, 13 cigarette smoking, and 13 non-smoking) | Observational | Mean concentration of PM2.5 | Air quality at shisha smoking venues had hazardous air quality | Shisha smoking venues had an average PM2.5 of 1745 μg/m3 | Venues with other sources of indoor air pollution and non-air-conditioned venues exposed to outdoor pollution were excluded. Samples were obtained before entering the venues to calibrate the device |
| Zeidan et al23 | 2014 | Lebanon | 147 people surveyed | Observational | Questionnaires on sociodemographic characteristics, respiratory symptoms and exposure to second-hand smoke. Exhaled CO levels | Second-hand waterpipe smoke may cause respiratory symptoms in non-smokers | Of the 147 surveyed, 48 were exposed only to second-hand waterpipe smoke. 58% reported a chronic cough | Measurements of expired-air CO were calibrated with local environmental CO concentration |
| Zhang et al16 | 2013 | Canada | Indoor (n=12) and outdoor (n=5) air quality was assessed in Toronto, Canada waterpipe cafes | Observational | Air nicotine, fine PM less than 2.5 μm in diameter, and ambient CO | Air quality of waterpipe cafés is a health hazard. Waterpipe smoking should be eliminated from indoor and outdoor hospitality venues | Indoor values were 1419 µg/m3 for PM2.5, 17.7 ppm for ambient CO, and 3.3 µg/m3 for air nicotine. Outdoor values were 80.5 µg/m3 for PM2.5, 0.5 ppm for ambient CO, and 0.6 µg/m3 for air nicotine | Measurements taken as far as possible from kitchen areas and open windows to reduce contamination. Background readings obtained outdoors in areas without nearby smokers |
3-HPMA, 3-hydroxypropylmercapturic acid; CO, carbon monoxide; EPI, Environmental Performance Index; LPS, lipopolysaccharides; NA, not applicable; NNAL, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; NNK, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone; PAH, polycyclic aromatic hydrocarbon; PM, particulate matter.