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Satisfying indoor air quality in public environments has become essential in cities. In the present study, indoor PM2.5, CO2, NO2, SO2, nicotine, and BTEX have been assessed in 12 categories of public places. The highest average concentrations of PM2.5, NO2, and SO2 were observed in waterpipe cafés (233, 29.6, and 5.1 µg/m3), whereas the lowest concentrations were found in health clubs and hospitals, respectively. Moreover, indoor BTEX concentration varied from 69.5 µg/m3 (passenger terminals) to 1739.2 µg/m3 (elderly care centers). Given nicotine, the highest concentrations were found in waterpipe cafés, ranging from approximately 11.0 to 50 µg/m3. The mean hazard quotient (HQ) and Hazard Index (HI) for benzene, toluene, ethylbenzene, and xylene were calculated in all types of public environments, and results showed that the amount of HQ and HI in none of the places was more than 1. Furthermore, the lifetime cancer risk (LTCR) exceeded the guideline threshold in hospitals, restaurants, elderly care centers, passenger terminals, movie theaters, and beauty salons. The findings of our study indicate that the indoor air quality in most public settings within Tehran city is not acceptable and necessitates appropriate management. These findings underscore the importance of monitoring indoor air quality and implementing effective strategies to mitigate exposure to air pollutants. [ABSTRACT FROM AUTHOR]

This study aimed to assess hydrogen sulfide (H2S) concentrations in the pool indoor air of hot springs and its link to some physicochemical properties of the springs in Ardabil province. Twenty-two hot springs from different regions were selected and monitored for H2S concentrations using a portable gas meter. Respective mean concentrations of H2S in hot springs indoor air were 9.11 § 11. Ghotour Souei hot springs had the highest concentration of H2S with a mean concentration of 29.4 § 7.7 and 25.2 § 8.16 ppm at the source and general pool areas, respectively. Oxidation-reduction potential and pH of the water were the most important factor influencing H2S concentrations in the hot springs. H2S concentrations in indoor air of Ardabil hot springs were noticeably higher than OEL-TWA and OELSTEL, and therefore may pose important risks for human health on both short-and long-term exposures. [ABSTRACT FROM AUTHOR]

Nitrate has been identified as a major pollutant in water resources. In this study, two new adsorbents, namely, red local montmorillonite (RLM) and green local montmorillonite (GLM)were used as adsorbents, and their characteristics and performance in nitrate adsorption has been investigated. The most important factors in the adsorption process such as initial pH, adsorbent dosage, contact time and initial concentration of nitrate were investigated. Also, EDAX, BET, SEM and FTIR techniques were used to determine adsorbent characteristics. The results showed that the highest nitrate adsorption for both adsorbents obtained at low pH values,and removal efficiency increased by increasing the dosage and contact time and decreased by increasing the initial concentration of nitrate. EDAX technique showed that the amount of MgO in GLM and RLM were 2.6% and 1.4% respectively, indicating a double amount of MgO in GLM structure. MgO can have a very important role in nitrate adsorption but BET technique showed that the specific surface area of RLM is more than GLM. Overall results showed that the adsorption capacities of GLM and RLM were relatively high and the values were 89.2 and 87.7 mg/g, respectively. High adsorption capacity can nominate two new adsorbents for nitrate adsorption. Adsorption process followed the Langmuir isotherm and the experimental data followed the pseudo second-order kinetic. Also, the results of thermodynamic experiments showed that the adsorbing reaction for both adsorbents was exothermic and they occurred spontaneously. [ABSTRACT FROM AUTHOR]

Background: Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDFs) are highly toxic persistent organic pollutants (POPs), which can cause various health outcomes, such as cancer. As a part of the National and Sub-national Burden of Disease Study (NASBOD), we aimed to estimate dioxins and furans national emissions, identify their main sources, estimate daily intake doses, and assess their trend from 1990-2010 in Iran. Methods: The Toolkit for Identification and Quantification of Releases of Dioxins, Furans and Other Unintentional POPs, which is developed by the United Nations Environment Programme (UNEP 2013), was used to estimate the emissions of PCDD/PCDFs from several sources into the air, water, land, residue, and other products. The daily intake doses were estimated using a linear regression of estimated emissions by UNEP Toolkit and average intake doses in other countries. Finally, the trend of PCDD/PCDFs emissions and daily intake doses were explored from 1990-2010. Results: The total emissions were estimated as 960 g Toxic Equivalents (g TEQ) for 1990 and 1957 g TEQ for 2010 (18.2 and 26.8 g TEQ per million capita, respectively). The estimations suggest that albeit contribution of open burning to PCDD/PCDFs emissions has been declining from 1990 to 2010, it remained the major source of emissions in Iran contributing to about 45.8% out of total emissions in 1990 to 35.7% in 2010. We further found that PCDD/PCDFs are mostly emitted into the ambient air, followed by residue, land, products, and water. The daily intake doses were estimated to be 3.1 and 5.4 pg TEQ/kg bw/day for 1990 and 2010, respectively. We estimated an increasing trend for PCDD/PCDFs emissions and intake doses in Iran from 1990-2010. Conclusions: The high levels of emissions, intake doses, and their increasing trend in Iran may pose a substantial health risk to the Iranian population. Further studies with more rigorous methods are recommended but this should not circumvent taking appropriate policy actions against these pollutants. Currently, Iran has no standard for dioxins and furans. Adaptation of the World Health Organization recommended guidelines might be an appropriate starting point to control dioxins and furans emissions. [ABSTRACT FROM AUTHOR]

Objectives: National ambient air quality standards (NAAQS) are critical tools for controlling air pollution and protecting public health. We designed this study to 1) gather the NAAQS for six classical air pollutants: PM 2.5 , PM 10 , O 3 , NO 2 , SO 2 , and CO in the Eastern Mediterranean Region (EMR) countries, 2) compare those with the updated World Health Organizations Air Quality Guidelines (WHO AQGs 2021), 3) estimate the potential health benefits of achieving annual PM 2.5 NAAQS and WHO AQGs per country, and 4) gather the information on air quality policies and action plans in the EMR countries. Methods: To gather information on the NAAQS, we searched several bibliographic databases, hand-searched the relevant papers and reports, and analysed unpublished data on NAAQS in the EMR countries reported from these countries to the WHO/Regional office of the Eastern Mediterranean/Climate Change, Health and Environment Unit (WHO/EMR/CHE). To estimate the potential health benefits of reaching the NAAQS and AQG levels for PM 2.5 , we used the average of ambient PM 2.5 exposures in the 22 EMR countries in 2019 from the Global Burden of Disease (GBD) dataset and AirQ+ software. Results: Almost all of the EMR countries have national ambient air quality standards for the critical air pollutants except Djibouti, Somalia, and Yemen. However, the current standards for PM 2.5 are up to 10 times higher than the current health-based WHO AQGs. The standards for other considered pollutants exceed AQGs as well. We estimated that the reduction of annual mean PM 2.5 exposure level to the AQG level (5 μg m -3 ) would be associated with a decrease of all natural-cause mortality in adults (age 30+) by 16.9%-42.1% in various EMR countries. All countries would even benefit from the achievement of the Interim Target-2 (25 μg m -3 ) for annual mean PM 2.5 : it would reduce all-cause mortality by 3%-37.5%. Less than half of the countries in the Region reported having policies relevant to air quality management, in particular addressing pollution related to sand and desert storms (SDS) such as enhancing the implementation of sustainable land management practices, taking measures to prevent and control the main factors of SDS, and developing early warning systems as tools to combat SDS. Few countries conduct studies on the health effects of air pollution or on a contribution of SDS to pollution levels. Information from air quality monitoring is available for 13 out of the 22 EMR countries. Conclusion: Improvement of air quality management, including international collaboration and prioritization of SDS, supported by an update (or establishment) of NAAQSs and enhanced air quality monitoring are essential elements for reduction of air pollution and its health effects in the EMR., Competing Interests: The authors declare that they do not have any conflicts of interest., (Copyright © 2023 Faridi, Krzyzanowski, Cohen, Malkawi, Moh’d Safi, Yousefian, Azimi, Naddafi, Momeniha, Niazi, Amini, Künzli, Shamsipour, Mokammel, Roostaei and Hassanvand.)