Exposure to ambient gaseous air pollutants and adult lung function: a systematic review.

Exposure to hazardous air pollutants is identified as most obvious premature mortality factors in the world. Numerous epidemiological studies have estimated exposure to air pollutants may cause pulmonary toxicity and the incidence of respiratory diseases including chronic obstructive pulmonary disease (COPD), chronic bronchitis and asthma. The currently research was performed to evaluation the association between gaseous pollutants and lung function in healthy adults. Articles related to this study were selected from researches of Scopus, PubMed, and Web of Science databases. A total of 2,644 articles were retrieved and 39 records were reviewed after removing duplicates and excluding irrelevant studies. The result of this systematic review indicated that there is some evidence on decreasing lung function with exposure to gaseous air pollutants (NO2, SO2, and O3) which can have negative effects on human health. Although according to the evidence changes in lung function are mostly linked to the exposure to environmental pollutants including CO, O3, NO2 and SO2, the results should be interpreted with caution considering some following issues discussed in this review. Therefore, further studies are required considering well-designed studies in large scales to strengthen the evidence.

Extraction and determination of organic/inorganic pollutants in the ambient air of two cities located in metropolis of Tehran.

In the present study, PM2.5, volatile organic compounds (VOC), heavy metals, and polycyclic aromatic hydrocarbons (PAHs)-bonded PM2.5 as well as asbestos fibers were investigated in two cities in the east of Tehran, Iran. To this end, 72 samples were collected from six stations located in the cities of Varamin and Pakdasht from March 2018 to March 2019. The concentration of BTEX compounds, PAHs, and heavy metals were measured using gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-Mas), and inductively coupled plasma atomic emission spectroscopy (ICP-OES), respectively. In addition, phase contrast microscopy (PCM) method was used to identify the properties of asbestos fibers. The results obtained from the present showed that the mean concentrations of PM2.5, heavy metals, PAHs, BTEX, and asbestos fibers were 52.05 µg/m3, 319.08 ng/m3, 3.97 ng/m3, 40.58 µg/m3, and 2.84 f/L, respectively. In addition, the results obtained from PCA and heavy metals sources showed that transport fleets were the natural source of most of these pollutants. In case of PAH sources, transport and incineration of coal had the highest contribution in the emission. Furthermore, the risk assessment showed that most of the compounds have a higher risk value than the guideline value spatial distribution and also showed that stations close to airports, city terminals, and highways were more polluted than other parts of the city. Therefore, in order to have healthy air and with the least pollution, it seems necessary to formulate the necessary strategies in the cities of Varamin and Pakdasht.

The effect of PM2.5-related hazards on biomarkers of bronchial epithelial cells (A549) inflammation in Karaj and Fardis cities.

Fine particles (especially PM2.5 particles) in ambient air can cause irreversible effects on human health. In the present study, seasonal variations in toxicity PM2.5 (cell viability and release of pro-inflammatory cytokines) were exposed human lung cells (A549) to concentrations of PM2.5 samples in summer (sPM2.5) and winter (wPM2.5) seasons. Cells were separately exposed to three concentrations of PM2.5 (25, 50, and 100 µg/mL) and three times (12 h, 1 and 2 days). We evaluated cell viability by MTT assay [3- (4, 5-dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide] and liberation of pro-inflammatory cytokines (interleukin-6 and interleukin-8) by the ELISA method. The toxicological results of this study showed that increasing the concentration of PM2.5 particulates and contact time with it reduces cell viability and increases inflammatory responses. Seasonal cytotoxicity of PM2.5 particles in high-traffic areas at summer season compared to winter season was lower. The lowest percent of viability at 2 days of exposure and 100 µg/mL exposure in the winter sample was observed. Also, PM2.5 particles were influential in the amount of interleukins 8 and 6. The average release level of IL-6 and IL-8 in the cold season (winter) and the enormous exposure time and concentrations (2 days-100 µg/mL) was much higher than in the hot season (summer). These values were twice as high for winter PM2.5 samples as for summer samples. The compounds in PM2.5 at different seasons can cause some biological effects. The samples' chemical characteristics in two seasons displayed that the PMs were diverse in chemical properties. In general, heavy metals and polycyclic aromatic hydrocarbons were more in the winter samples. However, the samples of wPM2.5 had a lower mass quota of metals such as aluminum, iron, copper, zinc, and magnesium. Concentrations of chromium, cadmium, arsenic, mercury, nickel, and lead were more significant in the sample of wPM2.5.

Potential cytotoxicity of PM2.5-bound PAHs and toxic metals collected from areas with different traffic densities on human lung epithelial cells (A549).

Laboratory and epidemiological researches have indicated that ambient air particulate matter have a plays critical role in causing diseases. The current research evaluated the chemical attributes of PM2.5 in the ambient air of the cities of Karaj and Fardis and determined its toxicological effects on human lung epithelial cells (A549). In the study city, 16 points were selected from the two high-traffic and low-traffic points for sampling. A sampling of ambient air was carried out in spring, summer, autumn, and winter 2018-19. Air sampling was performed for 24 h according to the EPA-TO/13A guidelines. To analyze of toxic metals and polycyclic aromatic hydrocarbons (PAHs), ICP-OES and GC-MS were used, respectively, and for cell toxicity analysis, an ELISA reader was used. Then from SPSS, Excel and R software were used for statistical analysis. The results of the current study indicated that the concentration of PAHs carcinogenic in the autumn season in high-traffic stations was the highest and equal to 9.3 ng/m3, and in the spring season in the low-traffic stations, it was the lowest and equal to 5.82 ng/m3. In general, during the period of study, Heavy metals including Zn, Fe, Pb, Cu, and Al had the highest concentration compared to other metals. However, Hg, Cr, As, Pb, Cu, Cd, and Zn were higher concentration in the winter and autumn seasons than in the spring and summer seasons. Cell viability measurements by using MTT showed that low-traffic and high-traffic stations had the highest toxicity in autumn season compared to other seasons. (p < 0.05). In general, high-traffic stations had the highest toxicity than low-traffic stations. The general conclusion of the present study was that PM2.5-bound PAHs and toxic metals, due to their high concentration, were toxic pollutants in air for residents of Karaj and Fardis. Also, the high concentration of PM2.5 caused the mitochondrial activity of A549 cells to stop and this stop was more significant in cold seasons and high-traffic areas.

Characterization, possible sources and health risk assessment of PM2.5-bound Heavy Metals in the most industrial city of Iran.

Air pollution associated with particulate matters results in different types of disease including allergy, lung destruction, heart failure, and related problems. This study has been designed and performed to examine the concentration of PM2.5-bound heavy metals, risk assessment, possible sources and effect of meteorological parameters on 17 sites of the air of the most industrial city of Iran (Karaj) in 2018-19. For this purpose, four samples were taken from every point of Karaj air over one year using a pump (Leland Legacy (SKC)) with flow rate of 3 L/min on PTFE filter for 24 h. Overall, 68 samples of PM2.5-bound heavy metals were collected. Note that during the sampling, atmospheric parameters including temperature, pressure, humidity, and wind speed were regularly recorded using PHB318 portable device. In examining the chemical composition of these particles, the concentration of metals (Al-Zn- Ar-Cd-Cr-Cu-Fe-Hg-Mn-Ni-Pb) was determined after digestion of the collected samples and through injection into ICP-OEC device. The results indicated that the mean annual concentration of PM2.5 particles range from 21.84 to 72.75 µg/m3. The mean concentration of heavy metals lied within the range of 25.63 to 336.27 ng/m3. Among heavy metals, the maximum concentration belonged to aluminum (277.95 ng/m3) and iron (336.27 ng/m3), which are known as elements with a ground source (sources such as car fuels, exhaust gases, decorative materials, batteries, indoor smoking, the paint used for painting walls, erosion and corrosion of rubber of cars). Meanwhile, there was a positive relationship between heavy metals and temperature(r: 0.418, p < 0.019), pressure (r: 0.184, p < 0.0.402), as well as wind speed (r: 0.38, p < 0.017), while an inverse relationship was observed with relative humidity (r: -0.219, p < 0.018). The ecological risk of the metals calculated was very notable, with the maximum environmental risk being related to cadmium in children (6.61) and manganese in adults (0.82). The largest HQ in children and adults was associated with Cr. Finally, ILCR values for cadmium in both children (1.19 E-04) and adult (4.81 E-04) groups indicated high risk of developing cancer in humans.

Spatial patterns and temporal variations of traffic-related air pollutants and estimating its health effects in Isfahan city, Iran.

Isfahan as an important industrial city has faced with air pollution recently. Thus, we assessed the spatial and temporal trends of ambient PM2.5, CO, SO2, and O3 and for estimating their health effect on Isfahan citizens between March 2018 and March 2019 through the AirQ+ software. Our results showed that citizens of Isfahan in almost 240, 167, and 134 of the days in the year has exposure to PM2.5, SO2, and O3 higher than the WHO daily guideline, respectively. Daily variations of PM2.5, CO, and SO2 concentration showed the increasing trend of pollutants in the morning to evening. The maximum concentrations of O3 were observed in the noonday. Also, the concentrations of these pollutants on Friday due to the holiday effect were higher than the weekdays. Except for O3, the PM2.5, CO, and SO2 concentrations in the cold months and cold seasons was higher compared with the hot months and hot seasons. The total number of deaths because of lung cancer, natural mortality, ischemic heart disease, chronic obstructive pulmonary disease,, stroke associated with ambient PM2.5 with the attributable proportion (AP) 11.43%, 11.63%, 15.96%, 15.15%, and 13.1% (95% CI) were 683, 19, 2, 202, and 55 cases, respectively. Therefore, the present study provides additional data for the provincial managers and politicians useful in planning proper strategies of air pollution control to decrease exposure and attributable mortalities.

Spatio-seasonal variation, distribution, levels, and risk assessment of airborne asbestos concentration in the most industrial city of Iran: effect of meteorological factors.

Like other dangerous pollutants in the air, asbestos has negative and adverse effects on human and animal health. The present study is designed to determine the concentration of asbestos in the air of the most industrial city of Iran (Karaj) in 2018-2019. For this purpose, 4 samples were taken from different areas of the air of Karaj during a year with an SKC pump and flow of 6 L/min for 8 h and in 45 days, and a total of 68 samples of asbestos fibers were collected. Then, the samples were analyzed by phase-contrast microscope (PCM) and scanning electron microscopy (SEM). Eventually, the health effects of asbestos fibers were evaluated by the IRIS EPA method. The average concentration of asbestos fibers was 1.84 f/L PCM and 18.16 f/L SEM. Also, the results of statistical correlation analysis indicated that asbestos fibers are positively correlated with wind speed but negatively correlated with the other three parameters (temperature, relative humidity, and pressure). On the other hand, the average annual risk of asbestos fiber in the ambient air of Karaj for all samples was in the range of 4.32 × 10-6 to 1.81 × 10-4 which in some places had more danger than the recommended risk range. According to the EPA guidelines, carcinogenicity acceptable levels are in the range of 10-4 and 10-6. Values higher than 10-4 have more carcinogenic risk and values lower than 10-6 have a lower carcinogenic risk.

Use of toenail-bounded heavy metals to characterize occupational exposure and oxidative stress in workers of waterpipe/cigarette cafés.

Tobacco smoke is known for releasing metals in indoor air of waterpipe/cigarette cafés. However, the worker exposure to metals, and its association with oxidative stress in these cafés are still unclear. To this end, 54 workers and 38 customers from waterpipe/cigarette cafés (the exposed group), 30 workers from non-smoking cafés (the control group 1 (CG_1)) and 32 individuals from the general population (the control group 2 (CG_2)) were selected and toenails samples were then taken from them. Our findings revealed a significant difference in terms of toenail-bounded metal levels between the exposure and control groups (CG_1 and CG_2) (Mann-Whitney U test, Pvalue < 0.05). This study has also indicated that "type of tobacco" could be considered as a predictor for toenail-bounded heavy metals. Furthermore, our research's results suggest that toenail-bounded heavy metals are positively and significantly correlated with urinary levels of 8- hydroxy-2'-deoxyguanosine (8-OHdG, as a biomarker for the degradation of deoxyribonucleic acid (DNA) oxidative stress). Therefore, it can be concluded that workers of waterpipe/cigarette cafés are at high risks of adverse health of DNA oxidative degradation.

Development and implementation of water safety plans for groundwater resources in the southernmost city of West Azerbaijan Province, Iran.

The transfer of water from the source to the consumption point is always associated with the possibility of contamination in any of its various components. To resolve this problem, the World Health Organization has considered a water safety plan. The purpose of this study is to implement water safety plan in the water supply system of Bukan city. This study was performed on Bukan's water supply system in 2019-20 using a software to guarantee the quality of the water safety plan and the WHO and IWA guidelines. The software checklists were prepared and after confirming the validity of the translation and its facial and content validity, it was completed based on the records of the Water and Sewerage Company and interviews with experts. Out of a total of 440 points of full-application of the program and 392 points for the reviewed phases, 183.6 points were acquired and 43.7% of WSP-coordinated implementation was observed. The highest percentage of WSP-coordinated implementation (75.2%) was assigned to the validation stage with the highest point, and the support program stage had the lowest percentage of performance (1.1%). Among the major components of the water supply system, the final consumption point received the most attention from the system. Given the lifespan of the introduction and use of WSP in the world, it was expected that better results would be obtained from evaluating the implementation and progress of this approach in Bukan's water supply system. However, the implementation rate of this program in this city compared to other cities in Iran, showed that according to the implementation time (one year), the obtained results are relatively convincing and good and the water supply system has a moderate level of safety.

Monitoring of airborne asbestos fibers in an urban ambient air of Mashhad City, Iran: levels, spatial distribution and seasonal variations.

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. The objectives of this study were to monitor the levels of asbestos fibers in ambient air of Mashhad, Iran during 2018, and to draw its Geographic Information System (GIS) distribution map for the city. In this descriptive study, 13 sampling points in Mashhad city were chosen. Sampling of asbestos was carried out for 3 hour during summer and winter at 2018. Sampling of asbestos was performed using MCE (Mixed Cellulose Ester) membrane filters (pour size 0.45 µm; diameter: 25 mm) and cassette holder and peripheral pump. The samples were the analyzed by the phase contrast microscopy (PCM) method (NIOSH7400). Also, to investigate the type of asbestos and for more accurate counting of fibers, Scanning Electron Microscopy (SEM) analysis was utilized. Meteorological parameter were recorded through portable devices. To draw the graphs, Excel, R and Arc GIS software were used. Results showed that the mean asbestos fiber concentrations were equal to 11.40 ± 2.14 and 14.38 ± 2.52 f/L in summer and winter, respectively. The maximum level of asbestos fiber was detected in the station of Baitolmoghaddas square by 26.64 ± 2.14 and 19.3 SEM f/L in winter and summer, respectively. High concentration of asbestos fiber observed in this study can be attributed to the heavy traffic, the presence of prominent industries in the vicinity of the study area, and topographic features. The results from this research recommends that suitable controlling policies should be regulated to reduce both ambient air asbestos and its adverse health endpoints in Mashhad.

Effect of photocatalytic pretreatment on the biodegradation of n-hexane vapours in a biofilter.

Hydrophobic volatile organic compounds (VOCs) such as n-hexane are not completely biodegradable by a single biofilter. So, in the present study, a photoreactor system packed with scoria granules coated with TiO2, as a pretreatment unit, was used for increasing the removal efficiency of n-hexane by a biofilter during an operation period of 191 days. The inlet and outlet concentration of n-hexane was analyzed with a gas chromatography coupled with a flame ionization detector (GC/FID). The results indicated that the removal efficiency of the single biofilter with input concentrations of 0.18 - 1 g/m3 at empty bed residence times (EBRTs) of 30, 60, and 120 s was 10.06%, 21.45%, and 46.8%, respectively. When the photoreactor was used as a pretreatment system, the removal efficiency of the combined system in corresponding EBRTs was improved to 39.79%, 63.08%, and 92.60%, respectively. The results proved that the combined system provided higher removal efficiencies than the single biofilter. Thus, the application of the photoreactor as a pretreatment step was much effective in increasing the removal efficiency of n-hexane from the polluted air by the biofilter.

Concentrations and mortality due to short- and long-term exposure to PM2.5 in a megacity of Iran (2014-2019).

The present study aimed to survey the spatial and temporal trends of ambient concentration of PM2.5 and to estimate mortality attributed to short- and long-term exposure to PM2.5 in Isfahan from March 2014 to March 2019 using the AirQ+ software. The hourly concentrations of PM2.5 were obtained from the Isfahan Department of Environment and Isfahan Air Quality Monitoring Center. Then, the 24-h mean concentration of PM2.5 for each station was calculated using the Excel software. According to the results, the annual mean concentration of PM2.5 in 2014-2019 was 29.9-50.9 µg/m3, approximately 3-5 times higher than the WHO guideline (10 µg/m3). The data showed that people of Isfahan in almost 58% to 96% of the days of a year were exposed to PM2.5 higher than the WHO daily guideline. The concentrations of PM2.5 in cold months such as October, November, December and January were higher than those in the other months. The zoning of the annual concentrations of PM2.5 in urban areas showed that the highest PM2.5 concentrations were related to the northern, northwestern, southern and central areas of the city. On average, from 2014 to 2019, the number of deaths due to natural mortality, lung cancer (LC), chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD) and stroke associated with ambient PM2.5 were 948, 16, 18, 281 and 60, respectively. The present study estimated that on average, 14.29% of the total mortality, 17.2% of lung cancer (LC), 15.54% of chronic obstructive pulmonary disease (COPD), 17.12% of ischemic heart disease (IHD) and 14.94% of stroke mortalities were related to long-term exposure to ambient PM2.5. So provincial managers and politicians must adopt appropriate strategies to control air pollution and reduce the attributable health effects and economic losses.