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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 2.5 , PM 10 and no 2 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 3 , all air pollutants demonstrated the lowest and highest concentrations in summertime and wintertime, respectively. The highest O 3 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 3 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 2.5 was the responsible air pollutant in Tehran. Amongst meteorological factors, temperature was the key influencing factor for PM 2.5 and PM 10 concentrations, while nebulosity and solar radiation exerted major influences on ambient SO 2 and o 3 concentrations. Additionally, there is a moderate coupling between wind speed and NO 2 and CO concentrations.

Fungi are usually presented in indoor environments and cause of many diseases. The aim of this descriptive study was to investigate the level of fungal contamination in hospital rooms. Sampling was conducted with an Andersen one-stage viable impactor (Quick Take-30) and counting plates containing a fungus-selective medium. A total of 120 air samples from ten hospital environments were performed. Airborne fungi concentrations were determined 72-120 hours after sampling. Total mean concentration of detected fungi in the hospital rooms was 55 ± 56 (mean ± SD) cfu/m3. The findings of the fungal concentration in the various hospital rooms revealed different levels of contamination: the lowest mean counts (37 ± 17 cfu/m3) were observed in NS 1 (Nursing Stations 1), and the highest (97 ± 217 cfu/m3) were reported in Orthopedics Operating Room (OOR). The most common fungal genus isolated were Penicillium (70%), Aspergillus (14%), Cladosporium (12%), Alternaria (2%) and others (2%). The obtained results showed that fungal concentrations in the present study were nearly high and these conditions should be considered as a risk factor for patients and other persons in the hospital.

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