2023 CiteScore: 1.9
eISSN: 2476-3071
Editor-in-Chief:
Ramin Nabizadeh Nodehi, Ph.D.
Vol 6 No 1 (2021): Winter 2021
Original Research
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Introduction: Air pollution is one of the main causes for the significant increase of respiratory infections in Tehran. In the present study, we investigated the associations between short-term exposure to ambient air pollutants with the hospital admissions and deaths.
Materials and methods: Health data from 39915 hospital admissions and 2459 registered deaths associated with these hospital admissions for respiratory infections were obtained from the Ministry of Health and Medical Education during 2014-2017. We used the distributed lag non-linear model (DLNM) for the analyses.
Results: There was a statistically positive association between PM2.5 and AURI in the age group of 16 years and younger at lags 6 (RR 1.31; 1.05-1.64) and 7 (RR 1.50; 1.09-2.06). AURI admissions was associated with O3 in the age group of 16 and 65 years at lag 7 with RR 1.13 (1.00-1.27). ALRI admissions was associated with CO in the age group of 65 years and older at lag 0 with RR 1.12 (1.02-1.23). PM10 was associated with ALRI daily hospital admissions at lag 0 for males. ALRI admissions were associated with NO2 for females at lag 0. There was a positive association between ALRI deaths and SO2 in the age group of 65 years and older at lags 4 and 5 with RR 1.04 (1.00-1.09) and 1.03 (1.00-1.07), respectively.
Conclusion: Exposure to outdoor air pollutiants including PM10, PM2.5, SO2, NO2, O3, and CO was associated with hospital admissions for AURI and ALRI at different lags. Moreover, exposure to SO2 was associated with deaths for ALRI.
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Introduction: Hospitals are sensitive places owing to the contagious nature of diseases transferred by patients to others such as health care workers and staff.
Materials and methods: The aim of the present work is to evaluate the type and concentration of bacterial and fungal bio-aerosols in the indoor air of four operating rooms (ORs) and four wards in Khalkhal, Iran during 2019. A total of 192 bacterial and fungal samples were collected.
Results: Mean total concentrations of airborne bacteria for ORs and wards were between 11±1.2 to 48±3.1 CFU/m3, respectively, while for airborne fungi values ranged from 95±5.6 to 51±1.2 CFU/m3, respectively. The predominant genera of airborne bacterial isolated (ORs vs. wards) were Staphylococcus epidermidis (72% vs. 58%), Group D Streptococcus (4% vs. 17%), Group A Streptococcus (13% vs. 3%), and Staphylococcus saprophyticus (6% vs. 4%). In addition, the main fungal species identified (ORs vs. wards) were Cladosporium sp. (37% vs. 38%), Penicillium sp. (28% vs. 22%), and Aspergillus Niger (21% vs. 12%). A statistically significant correlation was observed between the mean concentration of bio-aerosols and population density (p<0.05).
Conclusion: Furthermore, a statistically significant difference was observed between the mean concentrations of bio-aerosols and the values recommended by WHO (p<0.05), linked presumably to inadequate disinfection, improper design and operation of standard central ventilation (SCV), and the high density of visitors and patients. Addressing such issues can help reduce airborne fungi and bacteria in hospital.
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Introduction: Thyroid cancer is the most common endocrine malignant that is three times more prevalent in women than men. Fine particulate matter (PM2.5( has been indicated to affect Thyroid Hormone (TH) homeostasis. We sought to estimate the association between long-term exposure to ambient air pollution and the incidence of thyroid cancer in the Iranian female population.
Materials and methods: We extracted thyroid cancer incidence and ambient air pollution data from Iran from 2000 to 2019 for males and females for all age groups from the Global Burden of Disease (GBD) dataset. We entered the data into Joinpoint to present Annual Percent Change (APC) and Average Annual Percent Change (AAPC) and its confidence intervals. We entered the information into R3.5.0.
Results: Thyroid cancer in females had an upward trend [AAPC=4.9% (4.2-5.6)]. There was a correlation between ambient PM pollution (p≤0.001, r=0.84) and ambient ozone pollution (p≤0.001, r=0.94), and the incidence of thyroid cancer in females. The results of the analysis also showed a significant relationship between thyroid cancer incidence in females and secondhand smoke (p≤0.001, r=0.74).
Conclusion: This study indicated increasing trends in thyroid cancer incidence with exposure to ambient air pollution. Our novel findings provide additional insight into the potential associations between risk factors and thyroid cancer and warrant further investigation, specifically in areas with high levels of air pollution both nationally and internationally. However, causal relationships cannot be fully supported via ecological studies, and this article only focuses on Iran.
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Introduction: By crossing the borders of cities and countries, air pollution is now a global problem so that it can be claimed that there is no sound and clean air. This study aimed to investigate the effect of meteorological parameters on the concentration of particulate matter (PM2.5 and PM10) in the air of Arak city.
Materials and methods: In this study, Arak city was divided into three regions using geographic information system (GIS). Based on air pollution monitoring stations in Arak city, it was tried to select one station from each region for analysis. Meteorological parameters including temperature (°C), relative humidity (٪), precipitation (mm), and wind speed (m/s), were obtained from Arak Meteorological Organization. Finally, the association between the concentration of PM (PM2.5 and PM10) and meteorological parameters were evaluated by SPSS.
Results: Annual changes in PM (PM2.5 and PM10) showed that the average particle concentrations were 25.34 and 46.81 µg/m3 in the two study periods, respectively. It was also found that the citizens of Arak were 2.5 times more exposed to PM (PM2.5 and PM10) pollutants than the standard recommended by the World Health Organization. Our findings also showed strong positive linear correlations of wind velocity and temperature with PM2.5 and PM10, as well as relative humidity with PM10, and negative correlations of precipitation with PM2.5 and PM10, as well as relative humidity with PM2.5.
Conclusion: The distribution map of Arak city indicated that the citizens of Shariati station and the governorate office were facing high concentrations of pollutants, posing them to a serious threat. Moreover, more pollution was recorded toward the north and northwest of the city. To protect the health of citizens in Arak, therefore, it is necessary to adopt appropriate policies and rules to reduce the concentrations of PM and other pollutants in the air of this city.
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Introduction: Air pollution is one of the main problems of industrial and large cities like Tehran, due to its harmful effects, especially on human health.
Materials and methods: Based on the intensity and continuity of the standard air pollution index during 2004-2020 for 112 cases in Tehran, the principal component analysis method was applied in T-mode and clustering of days for similar 500hPa geopotential height changes were provided. The synoptic patterns leading to these different pollution cases were obtained.
Results: The study of the mentioned days shows the activity of five atmospheric patterns with the frequency of 47, 28, 12, 13, and 4%, respectively.
Conclusion: The first pattern happens during the cold season, associated with the simultaneous placement of the atmospheric ridge along with Siberian high-pressure system. The second group, which occurs mostly in summer and during late spring, is controlled with the predominant ozone pollutant. The main activity of the third pattern occurrences in summer and late spring, which is associated with the presence of monsoon Indian low-pressure on the southeastern regions in Iran. The fourth pattern, which occurs mostly in spring and autumn, associates with the establishment of dynamic low pressure in the western regions of Iran and Iraq, as well as the establishment of the thermal low-pressure system in the central part of the country. The last group is a local pattern that occurs due to the passage of the gust front and the shear of the wind field dust rise in the Tehran.
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Introduction: The adverse health effects of air pollution have been observed in many epidemiological studies. The aim of this research was to study the effects of air pollution on pulmonary functions in schoolchildren in Tehran city.
Materials and methods: Total number of 167 schoolchildren were selected to participate in this study. Data were analyzed using analysis of variance (ANOVA) and generalized estimating equation (GEE) to determine the relationship of air pollution and lung function tests.
Results: The result of this study showed that there are statistically significant differences in value of air pollution between areas. The results present that concentration of O3, PM10, NO2 has a negative association with lung function tests but concentration of CO, PM2.5, and SO2 had no association with decreased lung function tests. Time variable of air pollution was not statistically significant effect on lung function test.
Conclusion: In this study, we conclude that air pollution in Tehran city can be decreased lung function test indexes that may be affected by short-time exposure to air pollutant.
