Levels of particulate matters in air of the Gonabad city, Iran

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

Fine particles (especially PM_2.5 particles) in ambient air can cause irreversible effects on human health. In the present study, seasonal variations in toxicity PM_2.5 (cell viability and release of pro-inflammatory cytokines) were exposed human lung cells (A549) to concentrations of PM_2.5 samples in summer (sPM_2.5) and winter (wPM_2.5) seasons. Cells were separately exposed to three concentrations of PM_2.5 (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 PM_2.5 particulates and contact time with it reduces cell viability and increases inflammatory responses. Seasonal cytotoxicity of PM_2.5 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, PM_2.5 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 PM_2.5 samples as for summer samples. The compounds in PM_2.5 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 wPM_2.5 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 wPM_2.5.

Health risk assessment of PM2.5 on walking trips

PM_2.5 has an impact on residents' physical health during travelling, especially walking completely exposed to the environment. In order to obtain the specific impact of PM_2.5 on walking, 368 healthy volunteers were selected and they were grouped according to gender and age. In the experiment, the heart rate change rate (HR%) is taken as test variable. According to receiver operating characteristic (ROC) curve, the travel is divided into two states: safety and risk. Based on this, a binary logit model considering Body Mass Index (BMI) is established to determine the contribution of PM_2.5 concentration and body characteristics to travel risk. The experiment was conducted on Chang'an Middle Road in Xi'an City. The analysis results show that the threshold of HR% for safety and risk ranges from 31.1 to 40.1%, and that of PM_2.5 concentration ranges from 81 to 168 μg/m³. The probability of risk rises 5.8% and 11.4%, respectively, for every unit increase in PM_2.5 concentration and HR%. Under same conditions, the probability of risk for male is 76.8% of that for female. The probability of risk for youth is 67.5% of that for middle-aged people, and the probability of risk for people with BMI in healthy range is 72.1% of that for non-healthy range. The research evaluates risk characteristics of walking in particular polluted weather, which can improve residents' health level and provide suggestions for travel decision while walking.

The use of multi-criteria method in the process of threat assessment to the environment

Measurements of the content of trace elements, including toxic and carcinogenic metals, in various fractions of particulate matter PM are an important element of environmental monitoring and research involving their impact on human health. The article presents the measurement results of atmospheric composition of suspended dust (PM₁₀), respirable fraction (PM_2.5) and submicron particulate matter (PM₁) collected with the Dekati PM₁₀ cascade impactor. Samples were collected in the vicinity of four working power plants (from 28 May to 23 September 2014) and four coking plants (from 4 May to 28 August 2015) in Upper Silesia, Poland. The qualitative and quantitative analysis of the solutions: arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb) and selenium (Se) obtained for individual fractions was performed by inductively coupled plasma mass spectrometry, using the apparatus ICP-MS. The research results were used to determine a synthetic assessment of the threat to the anthropogenic environment and for the preparation of the ranking of the measured points.

The investigation of type and concentration of bio-aerosols in the air of surgical rooms: A case study in Shariati hospital, Karaj

The presence of bio-aerosols is one of the main causes of hospital infections that can be dangerous especially for immunocompromised patients. This research aimed to determine the relationship between hospital infections and surgical incision size in addition to determining the concentration and bacterial and fungal bioaerosols found in the operating rooms. This cross-sectional descriptive-analytic study was carried out in the operating rooms of Shariati Hospital in Karaj, Iran during the years 2016 and 2017. A total of 198 bacterial samples and 198 fungal samples were collected and analyzed using a passive sampling standard method (1/1/1) for 180 days. Tryptic Soy Agar (TSA) and Sabouraud Dextrose Agar (SDA) medium were used for bacterial and fungal samples, respectively. Relevant differential tests were used to determine the genus and species of bacteria and fungi such as DNase test, Bile-esculin, motility test urease test. In general, this work presents:

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The present evaluated the relationship between bioaerosols concentration and surgical incision size.

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The intraoperative concentration of bacterial and fungal bioaerosols in indoor air of the orthopedic, internal and cesarean operating rooms was significantly higher than their preoperative concentration (p-value<0.05).

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Also, there was not significant difference between the bacterial and fungal concentrations in various operating rooms) p-value<0.05).