Air pollutants associated with smoking in indoor/outdoor of waterpipe cafés in Tehran, Iran: Concentrations, affecting factors and health risk assessment.

Despite increasingly growth in waterpipe smoking in Tehran, so far no study has been conducted on the air quality of the waterpipe and cigarette cafés. Thirty-six cafés were selected and the concentration of three pollutants including formaldehyde, carbon monoxide and nicotine were measured in both indoor and outdoor air of cafés two times (week-day and weekend's session). Air sampling was performed for 180 min for each pollutant. It was observed that the concentration of pollutants inside the cafés was higher during weekend session (with a higher number of "active waterpipe heads") compared with findings during the week-day sessions. Furthermore, the concentration of pollutants in the indoor air of the cafés was significantly higher than that of the outdoors (p < 0.05). According to path analysis, the number of "active waterpipe heads" had the maximum impact on generation of pollutants inside the cafés, followed by the type of tobacco as the second influential factor. The average of lifetime cancer risk (LTCR) resulted by formaldehyde exposure through inhalation in waterpipe (WS), cigarette (CS), waterpipe and cigarette (WCS) and none-smoking (NS) cafés in week-day and weekend sessions were estimated to be 111 × 10-5 and 61.2 × 10-5, 33.7 × 10-5 and 39.4 × 10-5, 271 × 10-5 and 322 × 10-5, and 4.80 × 10-5 and 5.90 × 10-5, respectively, which exceed the limit value by the U.S.EPA and WHO. The concentration of pollutants in the indoor air of smoking cafés in Tehran is significantly high, such that it can pose serious risks for the health of both personnel and customers. Therefore, decision makers are expected to enact applicable and strict policies so as to abate this public health risk.

The effect of land use configurations on concentration, spatial distribution, and ecological risk of heavy metals in coastal sediments of northern part along the Persian Gulf.

In the present study, a total of 41 sediment samples were collected from the areas with different land uses: industrial (IS), urban (US), agricultural (AGS), and natural field (NS) in the northern coasts along the Persian Gulf from November 2016 to January 2017. Samples were analyzed to determine the concentration of heavy metals (Zn, Cu, Pb, Cd, Cr, and Ni). The mean concentration of Ʃ6 heavy metals in the samples taken from IS, US, AGS, NS were 2300.24, 251.02, 553.21, and 40.93 mg/kg, respectively. The predominant metals were Zn, Cu, and Pb and the mean concentrations of Ʃ3 metals (Zn, Cu, and Pb) in IS, US, AGS, NS areas were 2245.6, 241.44, 529.61, and 36.98 mg/kg, respectively. The results indicated that the mean concentrations of Ʃ6Metals/Ʃ3 metals in the IS and AGS samples were significantly higher than US and NS samples (p < 0.05). Heavy metal levels (mg/kg. dry weight) in all four land uses were as follows: industrial region: Pb (1347.44) > Cu (465.00) > Zn (427.16) > Cr (34.20) > Cd (19.45) > Ni (7.09); urban region: Zn (97.45) > Cu (79.90) > Pb (64.09) > Cr (5.30) > Ni (2.55) > Cd (1.73); agricultural region: Zn (247.88) > Pb (164.89) > Cu (116.84) > Cr (11.09) > Ni (7.45) > Cd (5.06); and natural fields: Zn (27.43) > Cu (6.34) > Pb (3.18) > Cr (1.94) > Ni (1.18) > Cd (0.83). According to geo-accumulation index (I-geo), the IS, US, and AGS were classified into "highly-extremely polluted", "unpolluted-moderately polluted" and "highly polluted", respectively. Similarly, in accordance with the ecological risk index (ERI), the IS and AGS fell into the very high and considerable categories, respectively, while US land uses area was categorized as low risk. Based on the results obtained from the present study, it can be concluded that the sediments of Asalouyeh coasts in the northern part of the Persian Gulf are heavily contaminated with heavy metals, causing serious negative effects on both the human being and environment.

Levels and health risk assessments of particulate matters (PM2.5 and PM10) in indoor/outdoor air of waterpipe cafés in Tehran, Iran.

To determine the concentration of particulate matters (PM2.5 and PM10), 36 samples were collected from indoor/outdoor air of hookah cafés (HS), cigarette cafés (CS), both hookah and cigarette (HCS), and no-smoking building (NS) in Tehran City from December 2017 to March 2018. The mean ± SD of PM10 concentration in the indoor air of the cafés in terms of HS, CS, HCS, and NS sites has been 702.35, 220.20, 1156.60, and 60.12 µg/m3, while for PM2.5, the values have been 271.92, 111.80, 619.10, and 22.25 µg/m3, respectively. It was also found that the PM concentration inside the cafés was higher during weekend session (with a higher number of active smokers), than during the weekday sessions. Moreover, the PM levels in the indoor air of the cafés were considerably higher than those of the outdoors (p < 0.05). Based on path analysis, the number of "active smokers" had the highest influence on production of PM inside the cafés, followed by the tobacco type. Finally, the mean excess lifetime cancer risk (ELCR) for PM2.5 in the indoor air of cafés was observed in the range of 0.64 × 10-5-14.98 × 10-5. Also, the mean of hazard quotient (HQ) for PM2.5 and PM10 was calculated in range of 0.82-18.4 and 0.16-3.28, respectively, which corresponds to an unacceptably high risk for human health. The PM levels in the indoor air of smoking cafés in Tehran are significantly high, such that it can cause serious risks for the health of both the customers and personnel. Thus, it is necessary that suitable controlling strategies be adopted for this public health threat.