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The presence of BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) compounds in beauty salons has raised concerns about potential health risks. This study aimed to measure the levels of BTEX compounds in the air of beauty salons in Lahijan, Iran and assess the associated health risks. Air samples were collected from 15 beauty salons, and the concentrations of BTEX compounds were measured according to 1501 NIOSH standard method. The results showed that the mean concentrations of benzene (20.62 µg/m 3 ), toluene (18.3 µg/m 3 ), ethylbenzene (38.36 µg/m 3 ), and O and P-xylene (27.35, 23.6 µg/m 3 ) were above the recommended levels. The indoor to outdoor ratios for benzene, toluene, ethylbenzene, O and P-xylene were 3.04, 2.36, 3.75, 4.89, and 6.54, respectively. Also, the toluene/benzene (T/B) ratio in indoor and outdoor was 20.9 and 2.68 respectively. Almost half of the technicians (49.12%) reported adverse health effects, including joint pain, itchy eyes and nose, and respiratory allergies. The IARC guideline suggests that there is a potential risk of cancer development for individuals in all salons with LCR values exceeding 10 -6 , but the HQ index values indicate no non-carcinogenic risk. The findings suggest that beauty salon workers and customers are at risk of developing health problems from exposure to BTEX compounds. Effective risk management strategies, such as proper ventilation, use of personal protective equipment, and substitution of harmful chemicals with safer alternatives, to minimize exposure and protect the health of salon workers and customers recommended., (© 2024. The Author(s).)

In the indoor environment of dental clinics, dental personnel and patients are exposed to a risk of infection because of the transmission of SARS-CoV-2 via particles or droplets. This study investigated the presence of SARS-CoV-2 RNA in indoor air of dental clinics in Tehran, Iran. Air sampling was done (n = 36) collecting particulate samples on PTFE filters at flow rates of 30 to 58 L/min. The samples were analyzed with novel coronavirus nucleic acid diagnostic real-time PCR kits. Only 13 out of 36 samples were positive for SARS-CoV-2 RNA. Logistic regression showed that sampling site's volume, PM 2.5 concentration, number of people, and number of active patient treatment units were significantly positively related with the presence of SARS-CoV-2 RNA. Thus, strategies to control the spread of COVID-19 should include reducing the number of infected people in dental clinics, adding filtration systems, and/or improving ventilation conditions., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The present study evaluated the concentrations, spatial distribution, seasonal variations, potential sources, and risk assessment of organic/inorganic pollutants in ambient air of Tehran city. Totally, 180 air samples were taken from 9 sampling stations from March 2018 to March 2019 and were analyzed to determine the concentrations of organic pollutants (BTEX compounds and PM 2.5 -bound PAHs) plus inorganic pollutants (PM 2.5 -bound metals and asbestos fibers). The results revealed that the mean concentrations of ∑ PAHs, BTEX, ∑ heavy metals, and asbestos fibers were 5.34 ng/m 3 , 60.55 µg/m 3 , 8585.12 ng/m 3 , and 4.13 fiber/ml in the cold season, respectively, and 3.88 ng/m 3 , 33.86 µg/m 3 , 5682.61 ng/m 3 , and 3.21 fiber/ml in the warm season, respectively. Source apportionment of emission of the air pollutants showed that PAHs are emitted from diesel vehicles and industrial activities. BTEX and asbestos are also released mainly by vehicles. The results of the inhalation-based risk assessment indicated that the carcinogenic risk of PAHs, BTEX, and asbestos exceeded the recommended limit by The US environmental protection agency (US EPA) and WHO (1 × 10 -4 ). The risk of carcinogenesis of heavy metal of lead and chromium also exceeded the recommended limit. Thus, proper management strategies are required to control the concentration of these pollutants in Tehran's ambient air in order to maintain the health of Tehran's citizens.

The main aims of the present research were (1) investigation of the temporal trends of atmospheric benzene concentrations in Tehran city during the period 2010 to 2013 and (2) assessment of carcinogenic and non-carcinogenic health risks of inhalation exposure to benzene. For the first objective, the data of ambient air benzene concentrations were derived from 15 air quality monitoring stations (AQMSs) in Tehran during the years 2010 to 2013 and they were temporally investigated after data cleaning and missing data imputation. The excess lifetime cancer risk (ELCR) and hazard quotient (HQ) were estimated to reveal the carcinogenic and non-carcinogenic health effects of exposure to ambient benzene. Our findings indicated that over 2010-2013, annual mean concentrations of benzene were in the range of 1.84 to 2.57 μg m -3 , and the highest annual mean concentration was observed in 2011 with a mean of 2.57 μg m -3 . The four-year average concentration of benzene during the period from 2010 to 2013 was 2.14 μg m -3 . Furthermore, the HQ for inhalation exposure to ambient benzene was lower than the acceptable risk level (HQ < 1) over the study time period which indicated that the non-carcinogenic effects are very unlikely to happen. In addition, health risk assessment for ELCR showed that the potential cancer risk for inhalation exposure to benzene was 1.67 × 10 -5 over the study period, which is significantly higher than the limits recommended by the U.S. EPA (1 × 10 -6 ). Our study clearly proves that the ambient benzene concentration in Tehran has substantially higher carcinogenic effects on the population. Appropriate sustainable control measures should be taken to reduce air benzene concentration and protect public health.

This study characterized spatio-temporal variations in the concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds in the vicinity of gas and compressed natural gas (CNG) stations in Tehran, Iran. Health risk assessment (HRA) was computed using Monte Carlo simulations (MCS) for evaluating inhalation lifetime cancer risk (LTCR), the hazard quotient (HQ), and sensitivity analysis (SA) for BTEX exposure in different age groups (birth to <81) and as a function of distance (0-250 m) from the center of the stations. For all monitoring stations, the average values of benzene, toluene, ethylbenzene, and xylene in winter were 466.09 ± 132.25, 873.13 ± 233.51, 493.05 ± 141.22, and 910.57 ± 145.40 μg m -3 , respectively. The mean wintertime ratios of T/B for the 12 stations ranged from 1.69 to 2.04. Furthermore, there was no significant relationship between the concentration of BTEX with either the specific month or distance from the center of stations (p > 0.05). Factors promoting BTEX formation in the study region were fuel evaporation and gas/CNG station emissions. The LTCRs for the target compounds in the winter for different age groups and distances from the center of stations was limited to 2.11 × 10 -4 to 1.82 × 10 -3 and 2.30 × 10 -4 to 2.01 × 10 -3 , respectively, which exceeded proposed values by U.S. EPA. Moreover, the HQs for BTEX for three age groups and distances were limited to between 2.89 × 10 -5 and 9.33 × 10 -2 , which were lower than the acceptable limit (HQs < 1). The results of this work are applicable to similar areas that are heavily populated with vehicular traffic. This study motivates a closer look at mitigation strategies to limit the health effects of carcinogenic emissions such as benzene and ethylbenzene from gas/CNG stations., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

To determine the concentration of particulate matters (PM 2.5 and PM 10 ), 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 PM 10 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/m 3 , while for PM 2.5 , the values have been 271.92, 111.80, 619.10, and 22.25 μg/m 3 , 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 PM 2.5 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 PM 10 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.

Asbestos, as with other pollutants in the air, has adverse effects on the health of human beings and animals. Today, the relationship between presence of asbestos fibers in the air breathed by humans and developing serious diseases such as lung cancer (asbestosis) and mesothelioma has been proven. This study was designed and conducted within the time period of August 2017 and June 2018 to determine the concentration of asbestos fiber in the ambient air of Shahryar City and to evaluate their health effects for the general population of the city. For this purpose, samples were taken from four points, and overall 32 air samples were taken along the year. The samples were then analyzed by the phase contrast microscopy (PCM) method. Also, to investigate the type of asbestos and for more accurate counting of fibers, SEM analysis was utilized. Finally, based on the EPA IRIS method, the health effects resulting from asbestos risks were also evaluated. The results of this study indicated that the mean annual concentration of asbestos fiber in the ambient air of Shahryar City was obtained as 0.0019 f/ml PCM and 0.0072 f/ml SEM. Furthermore, the most polluted point was S1 point (0.0119 -0.0026 f/ml, PCM), while the lowest concentration was related to S4 point (0.001 f/ml PCM-0.0021 f/ml SEM). The mean annual risk resulting from airborne asbestos fiber in the ambient air of Shahryar City for all samples was obtained as 1.72 × 10 -6 to 2.2 × 10 -4 , which was higher than the recommended risk range in some points.

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 possible relationship between diet-related inflammation and the risk of prediabetes requires further investigation, especially in non-Western populations. We examined the ability of the dietary inflammatory index (DII) to predict the risk of prediabetes in a case-control study conducted at specialized centers in Esfahan, Iran. A total of 214 incident cases of prediabetes were selected with the nonrandom sampling procedure, and the 200 controls randomly selected from the same clinics were frequency-matched on age (±5 years) and sex. DII scores were computed based on dietary intake assessed using a validated and reproducible 168-item food-frequency questionnaire. Linear and logistic regression models were used to estimate multivariable beta estimates and odds ratios (ORs). Subjects in tertile 3 versus tertile 1 (T3VS1) of DII had significantly higher fasting plasma glucose (DII T3VS1 : b = 4.49; 95% CI 1.89, 7.09), oral glucose tolerance (DII T3VS1 : b = 8.76; 95% CI 1.78, 15.73), HbA1c (DII T3VS1 : b = 0.30; 95% CI 0.17, 0.42), low-density lipoprotein (DII T3VS1 : b = 16.37; 95% CI 11.04, 21.69), triglyceride (DII T3VS1 : b = 21.01; 95% CI 8.61, 33.42) and body fat (DII T3VS1 : b = 2.41; 95% CI 0.56, 4.26) and lower high-density lipoprotein (DII T3VS1 : b = -3.39; 95% CI -5.94, -0.84) and lean body mass (DII T3VS1 : b = -3.11; 95% CI -4.83, -1.39). After multivariate adjustment, subjects in the most pro-inflammatory DII group had 19 times higher odds of developing prediabetes compared with subjects in tertile 1 (DII T3VS1 : OR = 18.88; 95% CI 7.02, 50.82). Similar results were observed when DII was used as a continuous variable, (DII continuous : OR = 3.62; 95% CI 2.50, 5.22). Subjects who consumed a more pro-inflammatory diet were at increased risk of prediabetes compared with those who consumed a more anti-inflammatory diet.

The objective of this study was to identify the components, composition and production rate of dental solid waste and associated management practices in dental offices in Hamadan. A total of 28 offices, including ten general dentist offices, eight specialist dentist offices, five practical dentist offices and five denture maker offices were selected in a random way. Three samples from each selected type were taken and the waste was manually separated into 74 sub-fractions and each sub-fraction was weighed. The results showed that the total annual dental waste production in dental offices was 41947.43 kg. Domestic type, potentially infectious, chemical and pharmaceutical and toxic waste constituted 71.15, 21.40, 7.26 and 0.18%, respectively of this amount. Only seven fractions including gypsum, latex gloves, nylon, dental impression material, used medicine ampoules, saliva-contaminated paper towels and saliva ejectors constituted about 80% of the waste. It was also indicated that there were no effective activity for waste minimization, separation, reuse and recycling in dental offices and the management of sharps, potentially infectious waste and other hazardous waste was poor.

We determined the prevalence and risk factors for 3,4-methylenedioxy-methamphetamine (MDMA, "ecstasy") use among college students in Astara, a northern border city of Iran. In a cross-sectional questionnaire survey of 1226 students, the lifetime prevalence of ecstasy use was 5.6%. The lifetime prevalence of use of other drugs, mostly cannabis and opium, was 4.6%. A fifth of students (21.8%) were current cigarette smokers and 24.8% had ever used alcohol. After logistic regression, the factors influencing ever use of ecstasy were ever use of other drugs, ever use of alcohol, current cigarette smoking and living alone or with friends. Targeted prevention programmes should be conducted in all colleges.

Parasites are important enteric pathogens among patients with human immunodeficiency virus (HIV) infection. There have been very few reports on the prevalence of intestinal parasites among such patients in Iran. To determine the prevalence of intestinal parasites among HIV-positive individuals, we collected single stool samples and analyzed them for detection of various intestinal parasites from 206 HIV-positive individuals with different immune status visited in different medical centers in Iran. The data were tested for statistical significance with chi(2) and Mann-Whitney U tests. The overall prevalence of intestinal parasites was 18.4% (95%CI: 13.7, 24.3). More specifically, the following parasites were identified: Giardia lamblia (7.3%), Blastocystis hominis (4.4%), Entamoeba coli (3.9%), and Cryptosporidium parvum (1.5%). Other parasites observed included Strongyloides stercoralis and Hymenolepis nana in two cases and Dicrocoelium dendriticum in one. Of the 38 patients who tested positive for intestinal parasites, 15 (39.2%) had diarrhea. Intestinal parasites were significantly more common among patients with diarrhea than those without (P < 0.001). Further, CD4 counts were significantly lower among individuals with diarrhea than those without (P < 0.001). This study highlights the importance of testing for intestinal parasites among Iranian HIV-positive patients, especially those with low immunity presenting with diarrhea.

Introduction: The specificity of relationship of endoscopic evidence of nodular gastritis with Helicobacter pylori infection is unclear., Aim: To assess the relationship of endoscopic nodular gastritis and H. pylori infection among children., Methods: 124 children (median age 8.2 years, range 1-15) undergoing upper GI endoscopy for abdominal pain underwent urease test and histological examination of gastric mucosa to determine the presence and density of H. pylori infection, and presence and severity of gastritis., Results: H. pylori infection was detected in 57 (46%) children. Endoscopic nodular gastritis was present in 46 of these 57 patients (81%) and in 24 of 67 (36%) H. pylori-negative patients (36%). The frequency of endoscopic nodular gastritis was related to increasing age (p< 0.0001), presence of H. pylori, grade of histologic gastritis, and H. pylori density (p< 0.0001)., Conclusion: Endoscopic finding of nodular gastritis is associated with presence of H. pylori infection and active chronic gastritis in children.

The authors studied respiratory symptoms and lung function among welders at welding workshops, and among nonwelders, in Hamadan, Iran. They used a questionnaire to record demographic data, smoking habits, and respiratory symptoms. The authors measured pulmonary functions with subjects standing upright. They collected metal fume samples from the respiratory zone of workers and analyzed the samples by atomic absorption spectroscopy. The concentrations of iron and manganese were higher than threshold limit values. The prevalence of asthma and clinical symptoms was higher in welders than nonwelders. Also, bronchitis was more common among welders (17.45%) than among nonwelders (2.56%). The average respiratory function values of welders were lower than those of nonwelders, with a significant difference between the means (p < 0.001 for all terms). The results of this study also strongly suggest a synergistic relationship between the effects of smoking and welding exposure.

Background: Hepatitis A is an enterically transmitted disease that still remains endemic in many developing countries. In some countries improvements in living conditions have recently led to changing in epidemiology of hepatitis A virus (HAV) infection. In our country there are very few reports on prevalence of HAV infection., Objective: To determine the seroprevalence of anti-HAV IgG among children visited in pediatric hospitals of Tehran, Iran., Methods: The study group included 1018 children who were 6 months-14.9 years of age. These children were visited in four major pediatric hospitals of Tehran. The children were separated to three age groups: Group 1 (6 months-4.9 years; n = 469), Group 2 (5.0-9.9 years; n = 290), and Group 3 (10.0-14.9 years; n = 259). Serum anti-HAV IgG was tested with commercial ELISA kits. The data were tested for statistical significance with chi2 test., Results: In all subjects, seroprevalence of hepatitis A was 22.3% (95% CI: 19.7, 24.9). There was no significant difference between genders (22.2% vs. 22.5% in males and females, respectively) and among age groups (Group I was 22.1% and Group 3 was 25.9; p > 0.05)., Conclusions: In summary, it seems that HAV infection is not highly endemic at least in some urban areas of Iran. On the basis of this epidemiologic data, post exposure prophylaxis would be necessary for children and young adults, and hepatitis A vaccination strategy should be revised.