Publications by authors named "Mohammad Sadegh Hassanvand"

67 Publications

Prevalence and Predictors of Pre-Existing Hypertension among Prenatal Women: A Cross-Sectional Study in Ghana.

Iran J Public Health 2021 Jun;50(6):1266-1274

Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Background: We aimed to assess prevalence and predictors of pre-existing hypertension in pregnant women in three districts of Northern region, Ghana.

Methods: This cross-sectional study was conducted among 1626 women in the third trimester of pregnancy across four antenatal centers in 2018. A questionnaire was used to collect medical information including weight and height. We used descriptive statistics to characterize all qualitative variables and performed logistic regression analyses to estimate association of hypertension and other risk factors.

Results: We included 1626 women; mean age standard deviation (SD) of pregnant women was 27.4 (5.1) years. About 4.5% (95% confidence interval [CI]: 3.6-5.7) of pregnant women reported they had earlier been diagnosed of having hypertension by a doctor or midwife, before pregnancy. Obese pregnant women had 2.9 times increased adjusted odds of having hypertension relative to non-obese pregnant women (Odds Ratio (OR))=2.9, 95% [CI]: 1.39-5.85, =0.004). Further, gestational diabetes was a predictor of pre-existing hypertension at an increased odds of 4.9 times relative to those without gestational diabetes (OR= 4.9, CI: 0.92-26.75, =0.061). Women with two or more children had 3.2 times the adjusted odds of having hypertension (OR=3.2 CI: 1.59-6.69, =0.001).

Conclusion: Although the prevalence pre-existing hypertension was not too high, obesity, gestational diabetes and number of children were independent predictors of pre-existing hypertension in pregnant women.
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http://dx.doi.org/10.18502/ijph.v50i6.6428DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8410977PMC
June 2021

Assessment of burden of disease induced by exposure to heavy metals through drinking water at national and subnational levels in Iran, 2019.

Environ Res 2021 Sep 14;204(Pt B):112057. Epub 2021 Sep 14.

Workplace Health Promotion Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Health and Safety, and Environment (HSE), School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address:

The burden of disease attributable to exposure to heavy metals via drinking water in Iran (2019) was assessed at the national and regional levels. The non-carcinogenic risk, carcinogenic risk, and attributable burden of disease of heavy metals in drinking water were estimated in terms of hazard quotient (HQ), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY), respectively. The average drinking water concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and nickel (Ni) in Iran were determined to be 2.3, 0.4, 12.1, 2.5, 0.7, and 19.7 μg/L, respectively, which were much lower than the standard values. The total average HQs of heavy metals in drinking water in the entire country, rural, and urban communities were 0.48, 0.65 and 0.45, respectively. At the national level, the average ILCRs of heavy metal in the entire country were in the following order: 1.06 × 10 for As, 5.89 × 10 for Cd, 2.05 × 10 for Cr, and 3.76 × 10 for Pb. The cancer cases, deaths, death rate (per 100,000 people), DALYs, and DALY rate (per 100,000 people) attributed to exposure to heavy metals in drinking water at the national level were estimated to be 213 (95% uncertainty interval: 180 to 254), 87 (73-104), 0.11 (0.09-0.13), 4642 (3793-5489), and 5.81 (4.75-6.87), respectively. The contributions of exposure to As, Cd, Cr, and Pb in the attributable burden of disease were 14.7%, 65.7%, 19.3%, and 0.2%, respectively. The regional distribution of the total attributable DALY rate for all heavy metals was as follows: Region 5> Region 4> Region 1> Region 3> Region 2. The investigation and improvement of relatively high exceedance of As levels in drinking water from the standard value, especially in Regions 5 and 3 as well as biomonitoring of heavy metals throughout the country were recommended.
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http://dx.doi.org/10.1016/j.envres.2021.112057DOI Listing
September 2021

Effect of ambient air PM-bound heavy metals on blood metal(loid)s and children's asthma and allergy pro-inflammatory (IgE, IL-4 and IL-13) biomarkers.

J Trace Elem Med Biol 2021 Dec 28;68:126826. Epub 2021 Jul 28.

Department of Immunology, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Background: We investigated the concentrations of metals in fine particulate matter PM in the outdoor air around the home sites of 123 male children from Ahvaz, average age 7.56, along with their blood samples to measure pro-inflammatory responses (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13).

Methods: We measured 6 metals (As, Cd, Cr, Hg, Ni and Pb) in three Ahvaz's regions including industrial (Padad), vehicle traffic (Golestan) and control (Kianpars).

Results: The higher concentrations of metals in the Padad as the industrial ambient air i.e., arsenic, cadmium, chromium, mercury and nickel coincided with the higher concentrations of those metals in exposed children (P < 0.05) versus the controls. Children in Golestan, the high traffic air pollution area had the highest lead concentrations (p < 0.05). Also a significant association was shown in Padad between blood arsenic and IgE (β = 26.59, P < 0.001), IL-4 (β = 172.1, P < 0.001) and IL-13 (β = 14.84, P < 0.001), blood chromium and IgE (β = 10.38, P < 0.001), IL-4 (β = 75.27, P < 0.001) and IL-13 (β = 5.27, P < 0.001) and blood mercury and IgE (β = 13.11, P < 0.001), IL-4 (β = 108.09, P < 0.001) and IL-13 (β = 7.96, P < 0.001) and blood lead and IgE(β = 0.92, P = 0.025), IL-4(β = 7.16, P < 0.001) and IL-13(β = 0.58, P = 0.003). However, no significant relation was found for Cadmium, Nickel in blood with IgE, IL-4 and IL-13 levels. Moreover, children from industrial areas showed significantly higher concentrations of IgE (mean = 146.44 pg/200landa, P < 0.001), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 52.93 pg/200landa, P < 0.001) versus Golestan and Kianpars.

Conclusion: Children residing in an industrial area with high concentrations of metals in PM had high metals in blood and high production of IgE, IL-4 and IL-13, reflecting an immune dysregulation and brisk inflammatory responses.
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http://dx.doi.org/10.1016/j.jtemb.2021.126826DOI Listing
December 2021

Level of air BTEX in urban, rural and industrial regions of Bandar Abbas, Iran; indoor-outdoor relationships and probabilistic health risk assessment.

Environ Res 2021 09 22;200:111745. Epub 2021 Jul 22.

Department of Environmental Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. Electronic address:

This study focused on the measurement of BTEX (benzene, toluene, ethylbenzene and xylene) concentrations in the air of various regions and indoor-outdoor environments in Bandar Abbas, Iran. Air samples were taken actively and analyzed by gas chromatography-mass spectrometry (GC-MS) during two one-month periods i.e., Feb 2020 (period I) and Sep/Oct 2020 (period II). The mean air temperature and the levels of all BTEX compounds were higher in period II. The highest total BTEX (t-BTEX) levels (median [min-max]) were found in the urban region (18.00 [5.21-67.24] μg m), followed by industrial region (7.00 [2.05-14.76] μg m) and rural region (2.81 [ND-7.38] μg m). The significant positive correlations between all BTEX compounds and T/B ratio >1 indicated the vehicular traffic as the main source of emission. At 95th percentile probability, the non-cancer risk of t-BTEX in urban region was only less than one order of magnitude below the threshold level of unity (1.91E-01) and the cancer risk of benzene exceeded the recommended level of 1.0E-06 by U.S. EPA in urban (7.69E-06) and industrial (2.97E-06) regions. It was found that the indoor/outdoor ratio of BTEX concentration in beauty salon and hospital was greater than 1. Overall, the current levels of BTEX in the ambient air of study area, especially near urban roadside and in some indoor environments, should not be overlooked and appropriate mitigation actions should be undertaken.
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http://dx.doi.org/10.1016/j.envres.2021.111745DOI Listing
September 2021

Investigating the relationship between particulate matter and inflammatory biomarkers of exhaled breath condensate and blood in healthy young adults.

Sci Rep 2021 06 21;11(1):12922. Epub 2021 Jun 21.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Inflammatory biomarkers in exhaled breath condensate (EBC) are measured to estimate the effects of air pollution on humans. The present study was conducted to investigate the relationship between particulate matter and inflammatory biomarkers in blood plasma and exhaled air in young adults. The obtained results were compared in two periods; i.e., winter and summer. GRIMM Dust Monitors were used to measure PM, PM, and PM in indoor and outdoor air. A total of 40 healthy young adults exhaling air condensate were collected. Then, biomarkers of interleukin-6 (IL-6), Nitrosothiols (RS-NOs), and Tumor necrosis factor-soluble receptor-II (sTNFRII) were measured by 96 wells method ELISA and commercial kits (HS600B R&D Kit and ALX-850-037-KI01) in EBC while interleukin-6 (IL-6), sTNFRII and White Blood Cell (WBC) were measured in blood plasma in two periods of February 2013 (winter) and May 2013 (summer). Significant association was found between particulate matter and the white blood cell count (p < 0.001), as well as plasma sTNFRII levels (p-value = 0.001). No significant relationship was found between particulate matter with RS-NOs (p = 0.128), EBC RSNOs (p-value = 0.128), and plasma IL-6 (p-value = 0.167). In addition, there was no significant relationship between interleukin-6 of exhaled air with interleukin-6 of plasma (p-value < 0.792 in the first period and < 0.890 in the second period). sTNFRII was not detected in EBC. Considering the direct effect between increasing some biomarkers in blood and EBC and particulate matter, it is concluded that air pollution causes this increasing.
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http://dx.doi.org/10.1038/s41598-021-92333-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8217428PMC
June 2021

Prenatal blood levels of some toxic metals and the risk of spontaneous abortion.

J Environ Health Sci Eng 2021 Jun 26;19(1):357-363. Epub 2021 Feb 26.

Department of Epidemiology and Environmental Health, Juntendo University Faculty of Medicine, Tokyo, Japan.

High-level toxic metal exposure has become rare in the recent years. Although, it has not known whether relatively lower exposure may adversely affect human reproductive system. Spontaneous abortion (SA) is a serious reproductive problem, which, in many cases, the cause(s) is not clearly understood. To assess the relationship between prenatal blood level of metals and SA risk, we compared blood concentration of some heavy metals in samples taken from mothers recruited in Tehran Environment and Neurodevelopmental Defects (TEND) study conducted on apparently healthy pregnant women in Tehran, Iran who subsequently experienced spontaneous abortion with mothers who their pregnancy ended to live births. During early gestation, 206 women were enrolled to the survey and followed up till fetal abortion or baby deliveries occur. Blood metal concentrations were measured using an inductively coupled plasma mass spectrometer. The mean blood levels of lead, antimony, and nickel were higher in SA than ongoing pregnancy; however, this difference was not statistically significant. When adjusted for covariates, the logistic regression analysis showed significant association between maternal age and the risk of SA in all models. Among toxic metals only antimony had a noticeable positive relation with the risk of SA (OR: 1.65, 95% CI:1.08-2.52, value: 0.02). Pearson's correlation coefficient showed significant ( < 0.05) positive correlations among prenatal blood metals levels, except for nickel. Although the present study failed to provide strong evidence for the effects of toxic metals on the occurrence of SA at the relatively low-levels, these metals should be avoided in women who plan pregnancy and/or during the early stages of gestation to prevent the chance of adverse effects.
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http://dx.doi.org/10.1007/s40201-020-00608-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8172701PMC
June 2021

Cardiovascular health effects of wearing a particulate-filtering respirator to reduce particulate matter exposure: a randomized crossover trial.

J Hum Hypertens 2021 May 24. Epub 2021 May 24.

Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.

This randomized crossover trial sought to determine whether wearing a high-efficiency particulate-filtering respirator (PFR) improves cardiovascular function over 48 h among healthy college students in Tehran. This trial was conducted from February 14th to 23rd, 2019 and twenty-six participants completed two 48-h intervention periods. Brachial blood pressure (BP) measured by 24-h ambulatory monitoring was the primary health outcome. Secondary outcomes included 48-h heart rate variability (HRV) indices, high-sensitive cardiac troponin (hs-TnT) and other biomarkers. The participants wore the PFR between 10.2 and 11.1 h while awake during the interventions. More than 80% of participants reported increased respiratory resistance while wearing the PFR due to a lack of an exhalation valve. There were no significant differences in brachial BP levels between subjects who wore PFR respirator and those did not. Except for high frequency (HF) power and heart rate (HR), no significant differences between interventions were observed for other HRV metrics. Wearing the PFR led to an increase of 66.0 ms (95% confidence interval [CI], 9.6-110.5) and 79.6 ms (95% CI, 19.0-140.1) in HF power during the first day when the two groups of participants wore the PFR. Night-time HR was significantly increased during the PFR intervention period. Other secondary outcomes were not significantly different between interventions. It is plausible that incomplete exposure reduction due to wearing the PFR less than half of the time or increased respiratory resistance mitigated potential health benefits. Additional trials are warranted to validate the CV protection of wearing PFRs in heavily-polluted cities.
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http://dx.doi.org/10.1038/s41371-021-00552-1DOI Listing
May 2021

Blood lead level monitoring related to environmental exposure in the general Iranian population: a systematic review and meta-analysis.

Environ Sci Pollut Res Int 2021 May 4. Epub 2021 May 4.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Exposure to lead can cause adverse health problems incorporating hypophosphatemia, heart and liver disease, cancers, neurological and cardiovascular diseases, central nervous disorders, and sensory disorders. This study investigated the blood lead level in the general Iranian population with environmental exposure to lead. In the presented systematic review and meta-analysis, the authors searched Iranian dataset, including Magiran, SID, Iranmedex, and Nopa, and the main dataset, comprising PubMed, Scopus, Embase, and Web of Science, all available articles until 12 January 2019, and extracting 55 studies (with 63 data for analysis) to a meta-analysis. A comprehensive meta-analysis software, pooled standard deviation, mean, sample size, and the utterly random effects model was analyzed in this study. The results showed that the overall mean BLL (95% CI) in total inquiries was 6.41 μg/dL (5.96 to 6.87). Besides, the results for gender and age subgroups were as follows: mean BLL, 6.47 μg/dL, 95% CI, 5.79, to 7.15, mean BLL, 6.44 μg/dL, 95% CI, 5.96, to 6.91, respectively. Conclusively the mean BLL in the Iranian population was higher than the recommended level by the US Centers for Disease Control and Prevention (CDC). Results indicated that the mean BLL in men and adults was more elevated than in women and children, respectively. Therefore, BLL monitoring and screening of the general Iranian population are is necessary to determine a reference value.
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http://dx.doi.org/10.1007/s11356-021-14148-2DOI Listing
May 2021

Source apportionment and deposition of dustfall-bound trace elements around Tabriz, Iran.

Environ Sci Pollut Res Int 2021 Nov 6;28(42):59403-59415. Epub 2021 Jan 6.

Health and Environment Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.

The monthly and spatial variations of atmospheric dustfall (DF) and their elemental components were determined. The DF sampling was performed using the ASTM method D-1739 from April 2017 to March 2018 in four urban and suburb sampling sites around Tabriz, Iran. The ICP-OES was utilized for the determination of the elemental components of DF.The results showed that the level of DF varied from 1.3 to 27.6 (8.0 ± 3.4) g/m.month during the sampling period, and the level of DF was higher in warm seasons than cold seasons. Also, it was revealed that the mean DF has a direct and significant relationship with temperature, wind speed, and relative humidity.The elements of Fe (11,997-17,093 mg/Kg and 71-81%) and Al (2903-6852 mg/Kg and 14-25%), which are the main elements of the Earth crust, were the dominant metals of DF among the analyzed elements. The lowest average value of the enrichment factor (EF) was for Al and was < 1, while the highest EF belonged to Hg, Pb, Cu, Sr, Mn, Co, Ni, and Cr, which were > 10 in all the sites, indicating that anthropogenic emission sources spread a considerable amount of trace elements in DF compared to the Lake Urmia bed or soil. The EF values for various elements (except than Cu and Hg) in cold seasons considerably increased compared to warm seasons.In all the study sites, Fe (540-1307 mg/m.yr) had the highest deposition rates among the metals. This study revealed that the Earth crust is the main source of DF in the region.
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http://dx.doi.org/10.1007/s11356-020-12173-1DOI Listing
November 2021

Associations between short term exposure to ambient particulate matter from dust storm and anthropogenic sources and inflammatory biomarkers in healthy young adults.

Sci Total Environ 2021 Mar 14;761:144503. Epub 2020 Dec 14.

Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Electronic address:

This study examined the association between particulate matter from anthropogenic and natural sources and inflammatory biomarkers, including hs-CRP, IL-6, sTNF-RII, and WBCs, in two groups of healthy young subjects. We followed up subjects of two panels (16 to 22 years old), including 22 subjects selected from the urban area (Tehran city) with high-level pollution background and 22 subjects selected from the rural area (Ahmadabad) with low-level pollution background. In each group, we collected 4 times blood samples in various air pollution conditions, In the subjects of the urban group, there was a substantial difference (p < 0.05) between inversion days and cold season control days, and between dust storm days and warm season control days for concentrations of hs-CRP, IL-6, and WBCs biomarkers. In the subjects of the rural group, a significant difference could be detected in the concentration of hs-CRP, IL-6, and WBCs biomarkers (p < 0.05) between inversion days and cold season control days, and between dust storm and warm control days. We found that the difference in concentrations of hs-CRP, IL-6, and WBCs biomarkers between dust storm days and warm control conditions in the rural group were higher than the difference in inversion and cold control conditions, which can be attributed to low background air pollution in the rural area. In the urban area, the health effect of anthropogenic sources of PM is higher than the dust storm condition, which can be attributed to the stronger effect of anthropogenic pollution effect.
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http://dx.doi.org/10.1016/j.scitotenv.2020.144503DOI Listing
March 2021

Ambient air particulate matter (PM) satellite monitoring and respiratory health effects assessment.

J Environ Health Sci Eng 2020 Dec 3;18(2):1247-1258. Epub 2020 Oct 3.

Department of pulmonary, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran.

Purpose: Air particulate matter with an aerodynamic diameter of 10 µm or less (PM) is one of the main causes of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study explored the relationship between PM by remote sensing and AECOPD in Chaharmahal-o-Bakhtiari province from 2014 to2018.

Method: PM concentrations were predicted and validated based on aerosol optical depth (AOD) from 161 images processed by MODIS sensor and ground air quality monitoring station data. Demographic information and spirometric indices of 2038 patients with AECOPD were collected and analyzed from the hospital during the studied periods. SPSS software was used to analyze the relationships between these two categories of information.

Results: There was a significant negative relationship between PM10 and FVC, FVC%, FEV1, FEV1%, FEF25-75, FEV1/FVC, PEF, and FEF25FVC indices (p < 0.05). The results showed that over 2014-2018, the annual mean of PM10 concentrations varied from 35 to 52 µg/m3. The result of the regression model showed that the patient's age, body mass index (BMI), and PM concentrations were the most affecting variables on the two important spirometric indices i.e., FVC% and FEV%. The PM concentrations and number of AECOPD patients had a similar pattern during the studied period. The women group, age group above 74 years, normal BMI, and non-smoking patients showed the most sensitivity to the PM concentrations.

Conclusions: Our findings provide supplementary scientific information on PM concentration related to the incidence of AECOPD and as a variable affecting the most important spirometry indicators by providing local decision-makers information needed to set a priority of air pollution control measures as well as health services.
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http://dx.doi.org/10.1007/s40201-020-00542-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7721783PMC
December 2020

Tehran environmental and neurodevelopmental disorders (TEND) cohort study: Phase I, feasibility assessment.

J Environ Health Sci Eng 2020 Dec 9;18(2):733-742. Epub 2020 Sep 9.

Department of Research Methodology and Data Analysis, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran.

Purpose: To advance knowledge about childhood neurodevelopmental disorders and study their environmental determinants, we conducted a study in Tehran, Iran to assess the feasibility of prospective birth cohort study.

Methods: We evaluated participation of pregnant women, feasibility of sampling biological material, and health care services availability in Tehran in four steps: (1) first trimester of pregnancy; (2) third trimester of pregnancy; (3) at delivery; and (4) two to three months after delivery. We collected related data through questionnaires, also various biological samples were obtained from mothers (blood, urine, milk and nails-hands and feet) and newborns (umbilical cord blood, meconium, and urine samples) from February 2016 to October 2017.

Results: overall 838 eligible pregnant women were approached. The participation rate was 206(25%) in our study and about 185(90%) of subjects were recruited in hospitals. Out of 206 participants in the first trimester, blood, urine, hand nail, and foot nail samples were collected from 206(100%),193(93%), 205(99%), and 205(99%), respectively. These values dropped to 65(54%), 83(69%), 84(70%), and 84(70%) for the remaining participants 120(58%) in the third trimester, respectively. Also, we gathered milk samples from 125(60%) of mothers at two to three months after delivery.

Conclusion: Our findings suggest that hospitals were better places for recruitment of subjects in a birth cohort in Tehran. We further concluded that birth cohort study recruitment can be improved by choosing appropriate gestational ages. Obtaining the newborn's urine, meconium, and umbilical cord blood were challenging procedures and require good collaboration between hospital staff and researchers.
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http://dx.doi.org/10.1007/s40201-020-00499-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7721759PMC
December 2020

Spatio-temporal variations of airborne bacteria from the municipal wastewater treatment plant: a case study in Ahvaz, Iran.

J Environ Health Sci Eng 2020 Dec 28;18(2):423-432. Epub 2020 Jul 28.

Diabetes Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

The study of bioaerosol dispersion in wastewater treatment plants (WWTPs) has received considerable attention. This study aimed to investigate the seasonal changes and spatial distributions of airborne bacteria around different parts of Ahvaz WWTP, the capital city of Khuzestan Province, Iran, over 4 months in the cold and warm seasons. Samples were collected from 2 and 10-m intervals of grit chamber (GCh), primary sludge dewatering basin (PSDB), aeration tank (AT), as well as 60m upstream (US) and downstream (DS) of the WWTP. Further, bacteria in the indoor air of administrative building (AB) of WWTP were investigated. Bioaerosols were collected by passive sampling method. The total bacteria count was 105.3 ± 98.5 CFU/plate/h. The dominant bacteria stood 2 m away from the AT with an average 244.2 ± 73.1 CFU/plate/h in the warm season while they were the lowest with an average 43 ± 11.4 CFU/plate/h in the 10-m distance of the GCh in the cold season. According to the sequencing results, the dominant bacterial species included (26.7%), (23.2%), (13.6%) and s (9.2%), respectively. There was a positive relationship between the release of bacteria, temperature and wind speed. However, there was a significant negative correlation between total bacteria concentration and humidity. There are accumulative perils to WWTP workers and neighbors exposed by persistent exposure to airborne bacteria. Therefore, AT should be paid more attention as a dominant source of airborne bacteria emissions, especially in the warm season.
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http://dx.doi.org/10.1007/s40201-020-00470-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7721828PMC
December 2020

Short-term effects of exposure to air pollution on biophysical parameters of skin in a panel of healthy adults.

Dermatol Ther 2020 11 23;33(6):e14536. Epub 2020 Nov 23.

Center for Research & Training in Skin Diseases & Leprosy, Tehran University of Medical Sciences, Tehran, Iran.

Little research on impact of air pollution on human skin is available. We aimed to clarify the association between acute exposure to criteria air pollutant with biophysical characteristics of the skin. We followed a panel of 20 volunteers free of any skin diseases in skin evaluation study in Tehran, Iran from April 2017 to April 2018. Two distinct body parts including middle forehead and inside the right upper arm were evaluated at six time periods. The associations of the weighted averages of personal exposure to air pollutants at 24 hours up to 6 days, and multiday average before the skin assessment with biophysical characteristics of normal skin including sebum content, hydration, transepidermal water loss (TEWL), erythema index, melanin index, pH, temperature, friction, and elasticity were assessed in a random intercept linear mixed effects modeling approach. We observed significant positive association for the arm sebum content with exposure to PM , and SO ; the arm and forehead TEWL with NO , the arm and forehead friction with O , and forehead hydration with PM and PM in early lags. We found significant negative association for the arm melanin index, elasticity, and erythema index with exposure to O ; and forehead elasticity with PM and PM . Our results provided some evidence that short-term exposure to particulate and gaseous air pollutants have detrimental effects on biophysical and biomechanical properties of skin. The association varied across body area and depended on pollutant type.
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http://dx.doi.org/10.1111/dth.14536DOI Listing
November 2020

Subnational exposure to secondhand smoke in Iran from 1990 to 2013: a systematic review.

Environ Sci Pollut Res Int 2021 Jan 2;28(3):2608-2625. Epub 2020 Nov 2.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Every year, almost eight million people die from tobacco-related diseases, among which around 1.2 million die from secondhand smoke (SHS) exposure. Generally, it is estimated that SHS constituents generated in the interval between puffs are approximately 3 times more toxic than those produced at the moment of puffing. There is no risk-free level of SHS exposure, and even brief exposure can be harmful to health. The aim of this study was to assess SHS exposure and its trend in the different provinces of Iran from 1990 to 2013. To collect available data on SHS exposure, a systematic review was performed. We searched international and national databases using a combination of Medical Subject Headings (MeSH) and relevant text words in the titles, abstracts, and/or keywords. Also, the data in national surveys were gathered. The frequency of exposure in different provinces as well as age, sex, and rural/urban areas were extracted. Afterwards, modeling was done to estimate SHS exposure from the smoking data. According to our findings, SHS exposure was more prevalent among young people. Moreover, this exposure was greater in rural areas as compared to urban areas. A national study on 13-15-year-old individuals showed the highest exposure occurred outdoors. In addition, a declining trend was observed on SHS exposure over time. It seems that attention to the importance of SHS exposure in researches in Iran dates back to 2001, and gradually, especially in recent years, further studies have been conducted on SHS exposure.
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http://dx.doi.org/10.1007/s11356-020-11199-9DOI Listing
January 2021

The concentration of BTEX compounds and health risk assessment in municipal solid waste facilities and urban areas.

Environ Res 2020 12 23;191:110068. Epub 2020 Aug 23.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Center for Solid Waste Management (CSWM), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran. Electronic address:

In this study, human exposure to benzene, toluene, ethylbenzene, xylenes (BTEX), along with their respective risk assessment is studied in four major units (n = 14-point sources) of the largest municipal solid waste management facilities (MSWF) in Iran. The results were compared with four urban sites in Tehran, capital of Iran. Workers at the pre-processing unit are exposed to the highest total BTEX (151 μg m). In specific, they were exposed to benzene concentrations of 11 μg m. Moreover, the total BTEX (t-BTEX) concentrations measured over the conveyor belt was 198 μg m at most, followed by trommel (104), and active landfills (43). The mean concentration of ambient t-BTEX in Tehran is 100 μg m. On average, xylenes and toluene have the highest concentrations in both on-site and urban environments, with mean values of 24 and 21, and 41 and 37 μg m, respectively. Even though the non-carcinogenic risk of occupational exposure is negligible, BTEX is likely to increase the chance of carcinogenic risks (1.7E-05) for workers at the pre-processing unit. A definite carcinogenic risk of 1.3E-04, and non-carcinogenic effect, of HI = 1.6 were observed in one urban site. With the exception of the pre-processing unit, the citizens of Tehran had higher exposure to BTEX. Overall, BTEX concentrations in the largest MSWF of Iran remains an issue of public health concern.
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http://dx.doi.org/10.1016/j.envres.2020.110068DOI Listing
December 2020

Exposure to endotoxins and respiratory health in composting facilities.

Ecotoxicol Environ Saf 2020 Oct 2;202:110907. Epub 2020 Jul 2.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Department of Research Methodology and Data Analysis, Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran. Electronic address: http://yunesian.tums.ac.ir.

The impact of bioaerosols in municipal solid waste management is nowadays identified as a growing health concern worldwide. In this study, exposure to endotoxin in composting facilities and its association with lung function and clinical symptoms was investigated in Tehran municipal solid waste management complex (Aradkooh) as one of the largest solid waste management facilities in the Middle East. Airborne endotoxins were collected between June and July 2019 and the concentrations were determined by Limulus Amebocyte Lysate (LAL) method. Healthy workers with no history of respiratory disease were recruited and data on clinical symptoms (cough, phlegm, wheezing, dyspnea, fatigue, headache, eye irritation, runny nose, runny eyes, and sore throat) was obtained by the modified American Thoracic Society questionnaire, and spirometric measurement was performed by an expert. The binary logistic regression test was used and adjusted for confounding variables. The results didn't show any difference in lung function parameters (FEV, FVC, FEV/FVC, PEF, FEF), and most of the respiratory symptoms despite a relatively high difference in the concentration of endotoxin observed in air samples of different locations. Only the increased risk of cough (OR 10.5, 95% CI: 2.4 to 44.8 in the moderately exposed group and 7.8, 95% CI: 1.6 to 39.1 in highly exposed ones), fatigue (OR 3.7, 95% CI: 1.2 to 11.7), and headache (OR 6.02, 95% CI: 1.4 to 24.5) were found in the exposed groups compared to controls after adjusting for age, active and passive smoking. However, findings of the study might be underestimated due to some issues including healthy worker effect, intra and intersubject variability, and self-reporting bias, thereby the results should be interpreted with caution. Although we did not find any relationship, due to the high concentrations of endotoxins observed in some sites, it is recommended to consider some possible prevention measures such as using personal protective equipment to reduce the exposure of workers at an acceptable level.
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http://dx.doi.org/10.1016/j.ecoenv.2020.110907DOI Listing
October 2020

Assessing BTEX exposure among workers of the second largest natural gas reserve in the world: a biomonitoring approach.

Environ Sci Pollut Res Int 2020 Dec 8;27(35):44519-44527. Epub 2020 Aug 8.

Department of Environmental Health, Research Center for Health Sciences, Institute of Health, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.

Urinary benzene, toluene, ethylbenzene, and xylenes (BTEX) can be used as a reliable biomarker of exposure to these pollutants. This cross-sectional study aimed to employ biomonitoring to assess BTEX exposure among South Pars Gas Field (SPGF) workers in Assaluyeh, Iran. Forty employees who were working on the site were recruited as the case group. Besides, 31 administrative employees were recruited as the control group. Pre-shift and post-shift spot urine samples were collected from the subjects in the case group, while the subjects in the control group provided mid-morning urine samples. Overall, 111 urine samples, including 80 samples from the case group and 31 samples from the controls, were collected. Gas chromatography-mass spectrometry (GC/MS) was used to determine the urinary levels of BTEX compounds. The median urinary levels of benzene, toluene, ethylbenzene, m,p-xylene, and o-xylene in the post-shift samples of the exposed group were 1.24, 2.28, 0.5, 1.32, and 1.5 μg/l, respectively. Significant differences were observed in urinary BTEX levels among smokers and non-smokers in both studied groups (p < 0.05). Accordingly, the median urinary BTEX concentrations in smokers were 2 to 6.5 times higher than the corresponding values in non-smoker subjects. Smoking status was the only predictor of the urinary BTEX concentration. Our findings revealed that refinery workers are exposed to significant levels of BTEX compounds. Considering the health risks associated with BTEX exposure for refinery workers, implementation of suitable control strategies, such as using appropriate personal protective equipment and improving on-site ventilation systems, are recommended reducing their exposure to BTEX via the inhalation.
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http://dx.doi.org/10.1007/s11356-020-10379-xDOI Listing
December 2020

Association of systemic inflammation and coagulation biomarkers with source-specific PM mass concentrations among young and elderly subjects in central Tehran.

J Air Waste Manag Assoc 2021 02 11;71(2):191-208. Epub 2020 Dec 11.

Department of Civil and Environmental Engineering, University of Southern California , Los Angeles, CA, USA.

In this study, we investigated the association between short-term exposure to different sources of fine particulate matter (PM) and biomarkers of coagulation and inflammation in two different panels of elderly and healthy young individuals in central Tehran. Five biomarkers, including white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF) were analyzed in the blood samples drawn every 8 weeks from the subjects between May 2012 and May 2013. The studied populations consisted of 44 elderly individuals at a retirement home as well as 40 young adults residing at a school dormitory. Positive Matrix Factorization (PMF)-resolved source-specific PM mass concentrations and biomarker levels were used as the input to the linear mixed-effects regression model to evaluate the impact of exposure to previously identified PM sources at retirement home and school dormitory in two time lag configurations: lag 1-3 (1-3 days before the blood sampling), and lag 4-6 (4-6 days before the blood sampling). Our analysis of the elderly revealed positive associations of all biomarkers (except hsCRP) with particles of secondary origin in both time lags, further corroborating the toxicity of secondary aerosols formed by photochemical processing in central Tehran. Moreover, industrial emissions, and road dust particles were positively associated with WBC, sTNF-RII, and IL-6 among seniors, while vehicular emissions exhibited positive associations with all biomarkers in either first- or second-time lag. In contrast, most of the PM sources showed insignificant associations with biomarkers of inflammation in the panel of healthy young subjects. Therefore, findings from this study indicated that various PM sources increase the levels of inflammation and coagulation biomarkers, although the strength and significance of these associations vary depending on the type of PM sources, demographic characteristics, and differ across the different time lags. : Tehran, the capital of Iran with a population of more than 9 million people, has been facing serious air pollution challenges as a result of extensive vehicular, and industrial activities in the previous years. Among various air pollutants in Tehran, fine particulate matters (PM, particles with aerodynamic diameters < 2.5 µm) are known as one of the most important critical pollutants, causing several adverse health impacts including lung cancer, respiratory, cardiovascular, and cardiopulmonary diseases. Therefore, a number of studies in the area have tried to investigate the adverse health impacts of exposure to PM. However, no studies have ever been conducted in Tehran to examine the association between specific PM sources and biomarkers of coagulation and systemic inflammation as indicators of cardiovascular disorders. Indeed, this is the first study in the area investigating the association of source-specific PM with biomarkers of inflammation including white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF). Our results have important implications for policy makers in identifying the most toxic sources of PM, and in turn designing schemes for mitigating adverse health impacts of air pollution in Tehran.
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http://dx.doi.org/10.1080/10962247.2020.1806140DOI Listing
February 2021

The acute effects of short term exposure to particulate matter from natural and anthropogenic sources on inflammation and coagulation markers in healthy young adults.

Sci Total Environ 2020 Sep 15;735:139417. Epub 2020 May 15.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran. Electronic address:

Airborne particulate matter is associated with increasing the risk of cardiovascular diseases. The purpose of this study was to investigate the association between air pollution conditions and MDA, vWF, and fibrinogen markers in the blood of two panels of healthy young individuals in an urban area in Tehran city with a high air pollution background and another group was living in a rural area (Ahmad Abad Mostofi), with a low air pollution background. In each group, 4 blood samples were taken as follows: one in inversion days, the second in winter, but during the existence of normal condition in terms of air pollution, the third sample in the spring during the normal condition in terms of air pollution and the fourth sample during the dust storm conditions. In the urban and rural groups, there was a significant difference between the concentration of MDA, vWF, fibrinogen between inversion and cold season control conditions, and between dust storm conditions and warm season control conditions (p < 0.05). The results showed that the association of dust storm condition on the measured biomarkers was stronger than the inversion condition, which health consideration in the dust conditions be taken into account similar to the inversion conditions.
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http://dx.doi.org/10.1016/j.scitotenv.2020.139417DOI Listing
September 2020

The burden of cardiovascular and respiratory diseases attributed to ambient sulfur dioxide over 26 years.

J Environ Health Sci Eng 2020 Jun 21;18(1):267-278. Epub 2020 Apr 21.

2Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.

Introduction: Developing countries, particularly those with a rapid development, are experiencing increasing pollution by sulfur dioxide (SO). Despite the considerable SO exposure effect on health, there is little evidence regarding this fact in Iran, as one of the largest oil and gas producing countries in the world. The present study, therefore, was designed to investigate the burden of cardiovascular and respiratory diseases attributed to the SO exposure in Iran, over a 26-year period.

Materials And Methods: All measured SO levels were collected from 92 air quality monitoring stations (AQMSs) in 29 cities, during 1996-2013. Since the study years were from 1990 to 2015, and also due to missing data at existing stations, the spatiotemporal model was used to estimate the exposure to this gas during this period. To calculate the burden of cardiovascular and respiratory diseases, the population attributable fraction (PAF) value was calculated, and the SO-attributed mortality and years of life lost (YLL) were determined per province, and in the whole country.

Results: The results of this study showed that the SO concentration was increased from 22.00 ppb (7.69-67.28) in 1990 to 27.81 ppb (9.88-82.27), in 2015. The lowest annual value of 11.53 ppb (4.68-32.06) and the highest value of 45.11 ppb (16.58-1226) were estimated at 2004 and 1997, respectively. There was a sinusoidal trend in the gas concentration changes. The highest occurrence of SO-attributed deaths due to cardiovascular and respiratory diseases were 0.080 (0.024-0.168) and 0.076 (0.026-0.165), and the lowest levels were 0.017 (0.004-0.044) and 0.047 (0.017-0.124), respectively.

Conclusions: According to the results in our country, the SO trend was sinusoidal during 26 years, with a recurrent rise occurring after each declining period. It is recommended to design the sustainable national method policies and programs with the continuous evaluation and modification for the reduction of fossil fuel consumption and further implementation in the use of clean energy.
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http://dx.doi.org/10.1007/s40201-020-00464-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7203314PMC
June 2020

Can respirator face masks in a developing country reduce exposure to ambient particulate matter?

J Expo Sci Environ Epidemiol 2020 07 21;30(4):606-617. Epub 2020 Apr 21.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Respirator face masks (RFMs) as a personal-level intervention is increasingly being utilized to reduce ambient particulate matter (PM) exposure, globally. We tested the effectiveness of 50 commercially available ones in reducing the exposure of ambient particle number concentrations (PNC), PM, PM, and PM (PM ≤ 10, 2.5, and 1 μm in diameter, respectively) in a traffic-affected urban site in Tehran. To examine the efficiency of RFMs, we applied a specific experimental setup including vacuum pumps, dummy heads, connecting tubes, glass chambers, and GRIMM Aerosol Spectrometer to measure all metrics after dummy heads. The average effectiveness of RFMs was in the range of 0.7-83.5%, 3.5-68.1%, 0.8-46.1%, and 0.4-32.2% in reducing ambient PNC, PM, PM, and PM, respectively. Considering all metrics, the highest effectiveness was observed always for Biomask, followed by 3 M 9332, due to their well-designed physical characteristics (e.g., adjustable nose clip for any face/nose shape, and size, soft inner material in the nose panel to provide a secure seal against leakage, adjustable or elasticated straps/ear loops to better adjust on any face). Biomask reduced ambient PM with a mean value of 94.6 μg m (minimum-maximum: 51.7-100.3 μg m), whereas it filtered on average just 29.0 μg m (25.7-43.5 μg m) of ambient PM and 18.2 μg m (14.7-21.8 μg m) of PM. A fuzzy analytical hierarchy process to find the most important design-related factors of RFMs affecting their effectiveness, which showed the exhalation valve and its diaphragm (20.4%), nose clip (19.7%), and cheek flaps (18.6%) are ranked as the main design-related variables. The fuzzy technique for order preference by similarity to ideal solution indicated that Biomask and 3M 9332 had scores of 1 and 0.97, the highest scores compared with other RFMs. This study provides crucial evidence-based results to elucidate the effectiveness and design-related factors of RFMs in real-environmental circumstances.
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http://dx.doi.org/10.1038/s41370-020-0222-6DOI Listing
July 2020

A field indoor air measurement of SARS-CoV-2 in the patient rooms of the largest hospital in Iran.

Sci Total Environ 2020 Jul 6;725:138401. Epub 2020 Apr 6.

Department of Virology, School of Public Health, Tehran University of Medical Sciences. Electronic address:

The coronavirus disease 2019 (COVID-19) emerged in Wuhan city, China, in late 2019 and has rapidly spread throughout the world. The major route of transmission of SARS-CoV-2 is in contention, with the airborne route a likely transmission pathway for carrying the virus within indoor environments. Until now, there has been no evidence for detection of airborne severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and this may have implication for the potential spread of the COVID-19. We investigated the air of patient rooms with confirmed COVID-19 in the largest hospital in Iran, on March 17, 2020. To collect the SARS-CoV-2 particles, ten air samples were collected into the sterile standard midget impingers containing 20 mL DMEM with 100 μg/mL streptomycin, 100 U/mL penicillin and 1% antifoam reagent for 1 h. Besides, indoor particle number concentrations, CO, relative humidity and temperature were recorded throughout the sampling duration. Viral RNA was extracted from samples taken from the impingers and Reverse-Transcription PCR (RT-PCR) was applied to confirm the positivity of collected samples based on the virus genome sequence. Fortunately, in this study all air samples which were collected 2 to 5 m from the patients' beds with confirmed COVID-19 were negative. Despite we indicated that all air samples were negative, however, we suggest further in vivo experiments should be conducted using actual patient cough, sneeze and breath aerosols in order to show the possibility of generation of the airborne size carrier aerosols and the viability fraction of the embedded virus in those carrier aerosols.
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http://dx.doi.org/10.1016/j.scitotenv.2020.138401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7194859PMC
July 2020

Investigation of aerosols pollution across the eastern basin of Urmia lake using satellite remote sensing data and HYSPLIT model.

J Environ Health Sci Eng 2019 Dec 10;17(2):1107-1120. Epub 2019 Dec 10.

5Medical Geography, Ministry of Health and Medical Education, Tehran, Iran.

Background: Desiccation of the world's second hypersaline lake, Lake Urmia, has drawn attention toward the feasibility of particle emissions from the lakebed to downwind regions. Therefore, this research was conducted to study spatiotemporal variations of aerosols across the eastern basin of the lake during 2001 to 2016.

Methods: The Aerosol Optical Depth (AOD) products of Moderate-resolution Imaging Spectroradiometer (MODIS), extracted from Terra platform for 999 rural and urban areas and compared over adjacent (Shabestar, Osku, Azarshahr, Ajabshir, Bonab, Malekan), middle (Tabriz and Maragheh) and far (Bostanabad, Heris, and Sarab) counties. Number of dusty days and direction of high wind speeds (≥ 11 m/s) were acquired from the East Azerbaijan Meteorological Organization and analyzed. Moreover, performing the backward trajectory model, the origin and distribution of aerosols were determined at altitudes of 500, 1000 and 2000 m.

Results: The spatiotemporal variations of AOD provided statistically significant correlations (R ≥ 0.5 and  < 0.05) against the number of dusty days. AOD value was higher between 2009 and 2016 and estimated to be 0.36, 0.33 and 0.31 over adjacent, middle and far areas, respectively. Analysis of wind direction and trajectory plots implied that the particulate matter (PM) of study area was mainly transported from Iraq and Syria, especially in April, May and June months.

Conclusions: PM has followed an increasing trend, while the adjacent areas have experienced higher pollution compared to far counties. The southwestern winds can play an important role in transportation of aerosols from either lakebed or western countries to the study area.
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http://dx.doi.org/10.1007/s40201-019-00425-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985422PMC
December 2019

Endotoxin and Der p1 allergen levels in indoor air and settled dust in day-care centers in Tehran, Iran.

J Environ Health Sci Eng 2019 Dec 11;17(2):789-795. Epub 2019 Aug 11.

1Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Background: Allergens like endotoxin and mite allergen Der p 1 are associated with early wheezing and asthma morbidity. Day-care centers can be an important source of exposure to allergens. The aim of this study was to evaluate children's exposure to endotoxin and mite allergen (Der p 1) associated with total suspended particulate matter (TSP) and settled dust in day-care centers in two phases in years of 2015 and 2016 in Tehran city, Iran.

Methods: Endotoxin and mite allergen Der p 1 in TSP and settled dust were measured in 23 day-care centers in Tehran. After collecting dust samples and weighting them, and then their extraction, Endotoxin and Der p 1 allergen were determined using QCL-1000 Endpoint chromogenic LAL Assay and ELISA, respectively.

Results: The mean concentrations of endotoxin and mite allergen Der p 1 in settled dust were 0.3 EU/mg and 0.2 ng/mg, respectively. The mean concentration of endotoxin and mite allergen Der p 1 in indoor air TSP were 0.8 EU/m and 0.4 ng/m, respectively. A significant negative correlation was found between endotoxin both in settled dust and in TSP with measured relative humidity in winter. Also, moderate correlation was observed between Der p 1 in settled dust and relative humidity in winter; however, the correlation between allergen in TSP and relative humidity was not significant.

Conclusion: Day-care centers can be an important source of endotoxin and Der p 1 allergen, so, implementation of proper interventions in these places can reduce exposure to them.
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http://dx.doi.org/10.1007/s40201-019-00395-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985405PMC
December 2019

Photochemical degradation of toluene in gas-phase under UV/visible light graphene oxide-TiO nanocomposite: influential operating factors, optimization, and modeling.

J Environ Health Sci Eng 2019 Dec 23;17(2):671-683. Epub 2019 Jul 23.

1Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

The current study aimed to investigate the removal efficiency of toluene using synthesized titanium dioxide-graphene oxide composites under visible light and UV irradiation. The characterization of synthesized composites was examined by field emission scanning electron microscope equipped with energy dispersive, X-ray diffraction and fourier transforms infrared. In order to find the optimum of the main experimental parameters affecting the removal efficiency of toluene including the length of the reactor, initial concentration, and flow rates, central composite design together with response surface methodology with R software was used. The initial concentration of toluene in the inlet of the reactor as well as its concentration in the outlet was measured using gas chromatography with the flame ionization detector. Analysis of variance results for the quadratic model showed that the highly significant and simple linear regression was established as a predicting model. Multiple and adjusted R were 0.965 and 0.974 for UV irradiation GO-TiO model and 0.951 and 0.959 for visible light GO-TiO model, respectively. As such, the differences less than 0.2 between multiple and adjusted R in two models indicate that two examined models were fitted well. The highest removal efficiency of toluene using UV irradiation GO-TiO and visible light GO-TiO was obtained at optimum condition; length of reactor 40 cm, initial concentration of 0.1 ppm, and flow rate equal to 1 l min, with 97.7 and 77.2%, respectively. The results indicated that the removal efficiency of toluene increased considerably with rising the length of the reactor, decreasing flow rates, and initial concentration.
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http://dx.doi.org/10.1007/s40201-019-00382-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985382PMC
December 2019

Temporal variations of ambient air pollutants and meteorological influences on their concentrations in Tehran during 2012-2017.

Sci Rep 2020 01 15;10(1):292. Epub 2020 Jan 15.

Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.

We investigated temporal variations of ambient air pollutants and the influences of meteorological parameters on their concentrations using a robust method; convergent cross mapping; in Tehran (2012-2017). Tehran citizens were consistently exposed to annual PM, PM and NO approximately 3.0-4.5, 3.5-4.5 and 1.5-2.5 times higher than the World Health Organization air quality guideline levels during the period. Except for O, all air pollutants demonstrated the lowest and highest concentrations in summertime and wintertime, respectively. The highest O concentrations were found on weekend (weekend effect), whereas other ambient air pollutants had statistically significant (P < 0.05) daily variations in which higher concentrations were observed on weekdays compared to weekend (holiday effect). Hourly O concentration reached its peak at 3.00 p.m., though other air pollutants displayed two peaks; morning and late night. Approximately 45% to 65% of AQI values were in the subcategory of unhealthy for sensitive groups and PM was the responsible air pollutant in Tehran. Amongst meteorological factors, temperature was the key influencing factor for PM and PM concentrations, while nebulosity and solar radiation exerted major influences on ambient SO and O concentrations. Additionally, there is a moderate coupling between wind speed and NO and CO concentrations.
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http://dx.doi.org/10.1038/s41598-019-56578-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6962207PMC
January 2020

National and sub-national exposure to ambient fine particulate matter (PM) and its attributable burden of disease in Iran from 1990 to 2016.

Environ Pollut 2019 Dec 4;255(Pt 1):113173. Epub 2019 Sep 4.

Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran; Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. Electronic address:

Ambient particulate matter is a public health concern. We aimed (1) to estimate national and provincial long-term exposure of Iranians to ambient particulate matter (PM) < 2.5 μm (PM) from 1990 to 2016, and (2) to estimate the national and provincial burden of disease attributable to PM in Iran. We used all available ground measurements of PM < 10 μm (PM) (used to estimate PM) from 91 monitoring stations. We estimated the annual mean exposure to PM for all Iranian population from 1990 to 2016 through a multi-stage modeling process. By applying comparative risk assessment methodology and using life table for years of life lost (YLL), we estimated the mortality and YLL attributable to PM for five outcomes. The predicted provincial annual mean PM concentrations range was between 21.7 μg/m (UI: 19.03-24.9) and 35.4 μg/m (UI: 31.4-39.4) from 1990 to 2016. We estimated in 2016, about 41,000 deaths (95% uncertainty interval [UI] 35634, 47014) and about 3,000,000 YLL (95% UI: 2632101, 3389342) attributable to the long-term exposure to PM in Iran. Ischemic heart disease was the leading cause of mortality by 31,363 deaths (95% UI: 27520, 35258), followed by stroke (7012 (5999, 8062) deaths), lower respiratory infection (1210 (912, 1519) deaths), chronic obstructive pulmonary disease (1019 (715, 1328) deaths), and lung cancer (668 (489, 848) deaths). In 2016, about 43% of all PM related mortality in Iran was, respectively, in the following provinces: Tehran (12.6%), Isfahan (9.3%), Khorasan Razavi (8.0%), Fars (6.5%), and Khozestan (6.4%). In summary, we found that the majority of Iranians were exposed to the levels of ambient particulate matter exceeding the WHO guidelines from 1990 to 2016. Further, we found that there was an increasing trend of total mortality attributed to PM in Iran from 1990 to 2016 where the slope was higher in western provinces.
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http://dx.doi.org/10.1016/j.envpol.2019.113173DOI Listing
December 2019

Short-term associations between daily mortality and ambient particulate matter, nitrogen dioxide, and the air quality index in a Middle Eastern megacity.

Environ Pollut 2019 Nov 28;254(Pt B):113121. Epub 2019 Aug 28.

Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.

There is limited evidence for short-term association between mortality and ambient air pollution in the Middle East and no study has evaluated exposure windows of about a month prior to death. We investigated all-cause non-accidental daily mortality and its association with fine particulate matter (PM), nitrogen dioxide (NO), and the Air Quality Index (AQI) from March 2011 through March 2014 in the megacity of Tehran, Iran. Generalized additive quasi-Poisson models were used within a distributed lag linear modeling framework to estimate the cumulative effects of PM, NO, and the AQI up to a lag of 45 days. We further conducted multi-pollutant models and also stratified the analyses by sex, age group, and season. The relative risk (95% confidence interval (CI)) for all seasons, both sexes and all ages at lag 0 for PM, NO, and AQI were 1.004 (1.001, 1.007), 1.003 (0.999, 1.007), and 1.004 (1.001, 1.007), respectively, per inter-quartile range (IQR) increment (18.8 μg/m for PM, 12.6 ppb for NO, and 31.5 for AQI). In multi-pollutant models, the PM associations were almost independent from NO. However, the RRs for NO were slightly attenuated after adjustment for PM but they were still largely independent from PM. The cumulative relative risks (95% CI) per IQR increment reached maximum during the cooler months, including: 1.13 (1.06, 1.20) for PM at lag 0-31 (for females, all ages); 1.17 (1.10, 1.25) for NO at lag 0-45 (for males, all ages); and 1.13 (1.07, 1.20) for the AQI at lag 0-30 (for females, all ages). Generally, the RRs were slightly larger for NO than PM and AQI. We found somewhat larger RRs in females, age group >65 years of age, and in cooler months. In summary, positive associations were found in most models. This is the first study to report short-term associations between all-cause non-accidental mortality and ambient PM and NO in Iran.
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http://dx.doi.org/10.1016/j.envpol.2019.113121DOI Listing
November 2019

Spatial homogeneity and heterogeneity of ambient air pollutants in Tehran.

Sci Total Environ 2019 Dec 26;697:134123. Epub 2019 Aug 26.

Centre for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Electronic address:

To investigate spatial inequality of ambient air pollutants and comparison of their heterogeneity and homogeneity across Tehran, the following quantitative indicators were utilized: coefficient of divergence (COD), the 90 percentile of the absolute differences between ambient air pollutant concentrations and coefficient of variation (CV). Real-time hourly concentrations of particulate matter (PM) and gaseous air pollutants (GAPs) of twenty-two air quality monitoring stations (AQMSs) were obtained from Tehran Air Quality Control Company (TAQCC) in 2017. Annual mean concentrations of PM, PM, and PM (PM) ranged from 21.7 to 40.5, 37.3 to 75.0 and 58.0 to 110.4 μg m, respectively. Annual mean PM and PM concentrations were higher than the World Health Organization air quality guideline (WHO AQG) and national standard levels. NO, O, SO and CO annual mean concentrations ranged from 27.0 to 76.8, 15.5 to 25.1, 4.6 to 12.2 ppb, and 1.9 to 3.8 ppm over AQMSs, respectively. Our generated spatial maps exhibited that ambient PM concentrations increased from the north into south and south-western areas as the hotspots of ambient PM in Tehran. O hotspots were observed in the north and south-west, while NO hotspots were in the west and south. COD values of PM demonstrated more results lower than the 0.2 cut off compared to GAPs; indicating high to moderate spatial homogeneity for PM and moderate to high spatial heterogeneity for GAPs. Regarding CV approach, the spatial variabilities of air pollutants followed in the order of O (87.3%) > SO (65.2%) > CO (61.8%) > PM (52.5%) > PM (48.9%) > NO (48.1%) > PM (42.9%), which were mainly in agreement with COD results, except for NO. COD values observed a statistically (P < 0.05) positive correlation with the values of the 90 percentile across AQMSs. Our study, for the first time, highlights spatial inequality of ambient PM and GAPs in Tehran in detail to better facilitate establishing new intra-urban control policies.
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http://dx.doi.org/10.1016/j.scitotenv.2019.134123DOI Listing
December 2019
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