Investigating the effect of several factors on concentrations of bioaerosols in a well-ventilated hospital environment.

This study characterized and quantified the bacterial and fungal bioaerosols in nine wards of the Razavi Hospital (Mashhad, Iran) that is equipped with an advanced heating, ventilating, and air conditioning (HVAC) system including HEPA filters for air cleaning. In this study, 432 samples were taken from the indoor air of multiple hospital wards during the morning and afternoon shifts during summer and autumn. The particle number concentrations with sizes of > 0.3, > 0.5, > 1, > 2, > 5, and > 10 µm were measured using a 6-channel handheld particle counter. A greater diversity of bioaerosol types were observed during the morning shifts and during summer. The microbial load was not affected significantly by the temperature, relative humidity, working shift, season, and number of visitors, indicating the effectiveness of a well-designed ventilation system to eliminate site-specific variations. For microbial number concentrations, a significant correlation was only observed between the number of particles with a diameter of > 10 µm and the airborne microbial loading. Thus, passive sampling may not properly reflect the actual concentrations of smaller bioaerosols. In conclusion, HEPA filters in the HVAC system successfully decreased the bioaerosol concentrations in the hospital environment. Additionally, we recommend that active sampling be used in cases where a well-functioning HVAC system exists.

Polycyclic aromatic hydrocarbons (PAHs) formation during the fast pyrolysis of hazardous health-care waste.

Health-care waste management is a challenge for the health sector. Currently, pyrolysis technologies are being used to treat medical waste that can convert it to a hydrocarbon fuel. In the present study, hazardous health-care waste was pyrolyzed using a continuous tubular fast pyrolysis reactor. Mass balance analysis and formation of the 16 polycyclic aromatic hydrocarbons (PAHs), characterized by USEPA as priority pollutants, and was studied during the pyrolysis process in a wide range of operation conditions, i.e., reaction temperature (300-700 °C), residence time (100-190 s) and waste particle size (1-3 cm). Response surface methodology (RSM) and central composite design (CCD) were applied to optimize the operating variables. Cracking and decomposition of feedstock occurred almost optimally in 700 °C resulting in the generation of 73.4% liquid and 24.1% char. The PAHs were characterized in significant concentrations in pyrolytic oil (121-29440 mg/lit) and char (223-1610 mg/kg) products. The formation of total USEPA listed PAH components varied by the operating ranges of temperature, residence time and waste size. In the pyrolytic oil phase, the formation of total PAHs was drastically increased by increasing the waste particle size. It is also found that increasing the temperature and having longer residence times have a high influence on the total 16 USEPA PAHs formation rate in the char phase. It is concluded that fast pyrolysis of hazardous health-care waste, as thermal treatment method, would influence the formation and destruction of PAHs and their fraction to a different extent depending on the role of operating variables.

Data on composition and production rate of dental solid waste and associated management practices in Qaem Shahr, Iran 2016.

This report investigates to analyse the production of waste in dental offices of Qaem Shahr city. In this study, from 120 dental offices in Qaem Shahr city, 21 offices were selected through random sampling. Sampling taken from 3 offices in 3 consecutive working days (on Sundays, Mondays and Tuesdays). The components were classified into three groups based on their specificity and potential. Total annual waste produced in Dentist Offices in Qaem Shahr city is 557.80 kg. In dental office, the amount of biohazard, chemical and pharmaceutical and domestic type wastes were 64.10, 2.70 and 33.20 respectively. Production percentages of biohazard, the highest weighted mean for potentially biohazard (155.25±0.63 g) and the lowest for chemical and pharmaceutical (6.35±1.85 g).

Air Quality Analysis by Using Fuzzy Inference System and Fuzzy C-mean Clustering in Tehran, Iran from 2009-2013.

BACKGROUND: Since the industrial revolution, the rate of industrialization and urbanization has increased dramatically. Regarding this issue, specific regions mostly located in developing countries have been confronted with serious problems, particularly environmental problems among which air pollution is of high importance. METHODS: Eleven parameters, including CO, SO2, PM10, PM2.5, O3, NO2, benzene, toluene, ethyl-benzene, xylene, and 1,3-butadiene, have been accounted over a period of two years (2011-2012) from five monitoring stations located at Tehran, Iran, were assessed by using fuzzy inference system and fuzzy c-mean clustering. RESULTS: These tools showed that the quality of criteria pollutants between the year 2011 and 2012 did not as much effect the public health as the other pollutants did. CONCLUSION: Using the air EPA AQI, the quality of air, and also the managerial plans required to improve the quality can be misled.