Iranian Journal of

Background and Objectives: Silica is an inorganic material that found in the nature in various forms. The hazards of crystal of silica or α-quartz (free silica) is greater than other forms. Exposure to dust that contains free silica result to pulmonary injury and result to silicosis and death finally. The present research was conducted in order to evaluate the level of workers exposure to free silica in air of Khaf Iron stone quarries.Materials and methods: The exposure level to total and respiratory dust measured based on personal and environmental sampling methods and concentration of dust determined based on gravimetric method. For determination of amounts of free silica, dust samples analyses based on X-ray diffraction (XRD) method, and results compared with standard levels.Results: The maximum amount of total dust and free silica measured in stone breaking station (800±155mg/m³ and 26.11±6.7 mg/m³) and minimum of them measured in official and safeguarding station (8.28±2.2 mg/m³ and 0.012±0.0019 mg/m³). The maximum amount of respiratory dust and free silica measured in red mound digging number 1 (66.14±13.45 mg/m³ and 1.48±0.39 mg/m³) and minimum of them measured in air hammer machine station (5.26±2.62 mg/m³ and 0.01±0.005 mg/m³).Conclusion: Amount of total dust only in official and safeguarding station was lower than standard levels of Iran. Amount of respiratory dust in all stations was greater than Iran standard levels. Furthermore the level of respiratory free silica only in airy hammer machine station was lower than standard level of Iran. Regarding to this amounts it is so essential to that with applying different methods generation and emission of dust protected.

Background and Objectives: Atmospheric transport is a key mode of microbial dispersal and the transmission of airborne microbe can have significant impacts on human health. The main objective of this study was to determine the concentrations of airborne bacteria in a children.s hospital.
Materials and methods: Three sampling points were selected. Airborne bacteria were collected with 6 days interval at each location using Quick take 30® sampler at an sampling rate of 28.3 l min-1 from November 2007 to March2008.
Results: The results showed that the highest indoor density of bacteria was 429 CFU/m3 that founded in oncology ward. Bacteria identified were representative of normal flora of the skin, respiratory and gastrointestinal tracts.
Conclusion:Our analysis revealed that colony of bacteria in 14% in patient room exceeded available guideline value for indoor air quality. That 11% cases was found in the oncology ward.

Background and Objectives :Microorganisms including Fungi, are among air-transmitted infectious agents at hospitals and patient care settings, which in addition to patients, can afflict Health Care Workers (HCWs) and visitors, and may results in extravagant economic burden and impact on human health. Use of nanotechnology and especially nanosilver particles is one of the methods which are used in infection control. This article is the result of a research project investigating nanosilver painting effect on bioburden of indoor hospital air.
Materials and Methods: The study was aimed to assess antifungal effects of nanosilver painting. Three rooms were selected at the infectious diseases ward of Imam Khomeini hospital complex. Two of the rooms were painted with two brands of nanosilver paints provided from two separate companies (as cases), and the third room with non-nanosilver paint brand(as control).
Results: Air sampling was carried out using a portable air pump (Quick Take 30) at pre-planned schedule Each Sampling was done in two minutes with the rate of 28.3 Liter per minute. Samples were transferred on Sabourauds Dextrose Agar culture, to count the colonies of fungal based on Colony Forming Unite (CFU/m3). Results were analyzed by ANOVA method.
Conclusion: Active sampling method was not able to show statistically significant reduction in the total fungal bioburden between the control and case rooms. In evaluating the time trend of the nanosilver paints effect, sampling measures revealed that nanosilver paints had statistically significant effect in fungal bioburden reduction in the first third( i.e. first month) of the study period.

Background and Objectives: In recent years exposure to fine airborne particles has been identified as an important factor affecting human health. Epidemiological studies have showed that the aerosol laden air can be an agent for microorganisms’ dispersion. Ignoring internal sources, ambient air quality significantly affects indoor air quality. Since people spend most of their times in the indoor spaces and little data are available on the general understanding of the indoor air quality, therefore, the aim of this study is to determine the particulate matter concentrations in indoor and ambient air of Tehran Children Medical Center Hospital.
Materials and Method: PM₁₀/PM_2.5 samples were collected in the indoor environment of the Tehran Children Medical Center Hospital and its adjacent outdoor environment by a portable GRIMM dust monitor model 1.108 from November 26 to March 10, 2007. The places of sampling for indoor and ambient air were in the patient room and the roof of the hospital respectively.
Results: The results showed that indoor PM₁₀ level was higher than WHO standards in 80% cases in patient room, whereas, for indoor PM_2.5 level, this value was 42 and 64% more than the EPA standards and WHO standards respectively. The relationship between outdoor and indoor particulate matters was examined by linear regression analysis. The indoor particulate matter levels were correlated with the corresponding ambient air ones.
Conclusion: Our analysis revealed that infiltration of ambient air could substantially increased indoor pollutants and thereby influences the indoor air quality.