Sibel Mentese

Bio: Sibel Mentese is an academic researcher from Çanakkale Onsekiz Mart University. The author has contributed to research in topics: Indoor air quality & Bioaerosol. The author has an hindex of 11, co-authored 26 publications receiving 1420 citations. Previous affiliations of Sibel Mentese include Hacettepe University.

Formaldehyde in the Indoor Environment

Abstract: 1.1. History Formaldehyde was described in the year 1855 by the Russian scientist Alexander Michailowitsch Butlerow. The technical synthesis by dehydration of methanol was achieved in 1867 by the German chemist August Wilhelm von Hofmann. The versatility that makes it suitable for use in various industrial applications was soon discovered, and the compound was one of the first to be indexed by Chemical Abstracts Service (CAS). In 1944, Walker published the first edition of his classic work Formaldehyde.(1) Between 1900 and 1930, formaldehyde-based resins became important adhesives for wood and wood composites. The first commercial particle board was produced during World War II in Bremen, Germany. Since 1950, particle board has become an attractive alternative to solid wood for the manufacturing of furniture. Particle board and other wood-based panels were subsequently also used for the construction of housing. Adverse health effects from exposure to formaldehyde in prefabricated houses, especially irritation of the eyes and upper airways, were first reported in the mid-1960s. Formaldehyde emissions from particle boards bonded with urea formaldehyde resin were soon identified as the cause of the complaints. As a consequence, a guideline value of 0.1 ppm was proposed in 1977 by the former German Federal Agency of Health to limit human exposure in dwellings. Criteria for the limitation and regulation of formaldehyde emissions from wood-based materials were established in 1981 in Germany and Denmark. The first regulations followed in the United States in 1985 or thereabouts. In Germany and the United States, large-scale test chambers were used for the evaluation of emissions. Although the chamber method is very reliable, it is also time-consuming and expensive. This meant there was a strong demand for simple laboratory test methods.(2)

Bacteria and Fungi Levels in Various Indoor and Outdoor Environments in Ankara, Turkey

Abstract: In this study, different types of indoor environments (primary school, kindergarten, cafeteria, restaurant, dormitory, dwelling, office, sport salon, library, classroom, and laboratory) and their outdoor environments were investigated in terms of bioaerosol contamination. A total of 120 environments were investigated in Ankara, Turkey. The single-stage Andersen sampler was used for viable bioaerosol sampling. During the sampling, indoor and outdoor temperature, relative humidity, and CO 2 concentration were measured. Total bacteria counts (TBC) and fungi concentrations varied on a large scale within and between the sampling site groups (10―10 3 CFU/m 3 ). The highest TBC levels were measured in kindergartens, primary schools, restaurants, high schools, and homes, while the highest mold levels were measured in kitchens, bathrooms, and offices. Micrococcus spp., Staphylococcus auricularis, and Bacillus spp. were predominant bacteria species and Penicillium spp., Aspergillus spp., and Gladosporium spp. were the most observed mold genera detected in the samples. Indoor-to-outdoor (I/O) ratios of the observed fungi counts were calculated as approximately around 1, and for bacteria counts these ratios were higher than 1. There was no statistical difference between indoor and outdoor mold levels, while a significant difference was found between indoor and outdoor bacteria levels (p < 0.001). A significant correlation between indoor CO 2 and bioaerosols indicates insufficient ventilation.

Seasonal and Spatial Variations of Bioaerosols in Indoor Urban Environments, Ankara, Turkey

Abstract: Seasonal and spatial variations of both levels and characteristics of airborne bacteria and fungi in various types of non-complaint indoor environments and their outdoors were investigated. Bioaero...

Formaldehyde in the Indoor Environment

Abstract: 1.1. History Formaldehyde was described in the year 1855 by the Russian scientist Alexander Michailowitsch Butlerow. The technical synthesis by dehydration of methanol was achieved in 1867 by the German chemist August Wilhelm von Hofmann. The versatility that makes it suitable for use in various industrial applications was soon discovered, and the compound was one of the first to be indexed by Chemical Abstracts Service (CAS). In 1944, Walker published the first edition of his classic work Formaldehyde.(1) Between 1900 and 1930, formaldehyde-based resins became important adhesives for wood and wood composites. The first commercial particle board was produced during World War II in Bremen, Germany. Since 1950, particle board has become an attractive alternative to solid wood for the manufacturing of furniture. Particle board and other wood-based panels were subsequently also used for the construction of housing. Adverse health effects from exposure to formaldehyde in prefabricated houses, especially irritation of the eyes and upper airways, were first reported in the mid-1960s. Formaldehyde emissions from particle boards bonded with urea formaldehyde resin were soon identified as the cause of the complaints. As a consequence, a guideline value of 0.1 ppm was proposed in 1977 by the former German Federal Agency of Health to limit human exposure in dwellings. Criteria for the limitation and regulation of formaldehyde emissions from wood-based materials were established in 1981 in Germany and Denmark. The first regulations followed in the United States in 1985 or thereabouts. In Germany and the United States, large-scale test chambers were used for the evaluation of emissions. Although the chamber method is very reliable, it is also time-consuming and expensive. This meant there was a strong demand for simple laboratory test methods.(2)

Enhanced photocatalytic performance of direct Z-scheme g-C3N4–TiO2 photocatalysts for the decomposition of formaldehyde in air

Abstract: Formaldehyde (HCHO) is a major indoor pollutant and long-term exposure to HCHO may cause health problems such as nasal tumors and skin irritation. Photocatalytic oxidation is considered as the most promising strategy for the decomposition of HCHO. Herein, for the first time, a direct g-C3N4–TiO2 Z-scheme photocatalyst without an electron mediator was prepared by a facile calcination route utilizing affordable P25 and urea as the feedstocks. Photocatalytic activities of the as-prepared samples were evaluated by the photocatalytic oxidation decomposition of HCHO in air. It was shown that the photocatalytic activity of the prepared Z-scheme photocatalysts was highly dependent on the g-C3N4 content. At the optimal g-C3N4 content (sample U100 in this study), the apparent reaction rate constant was 7.36 × 10−2 min−1 for HCHO decomposition, which exceeded that of pure P25 (3.53 × 10−2 min−1) by a factor of 2.1. The enhanced photocatalytic activity could be ascribed to the formation of a g-C3N4–TiO2 Z-scheme photocatalyst, which results in the efficient space separation of photo-induced charge carriers. Considering the ease of the preparation method, this work will provide new insights into the design of high-performance Z-scheme photocatalysts for indoor air purification.

Architectural design influences the diversity and structure of the built environment microbiome

Abstract: Buildings are complex ecosystems that house trillions of microorganisms interacting with each other, with humans and with their environment. Understanding the ecological and evolutionary processes that determine the diversity and composition of the built environment microbiome—the community of microorganisms that live indoors—is important for understanding the relationship between building design, biodiversity and human health. In this study, we used high-throughput sequencing of the bacterial 16S rRNA gene to quantify relationships between building attributes and airborne bacterial communities at a health-care facility. We quantified airborne bacterial community structure and environmental conditions in patient rooms exposed to mechanical or window ventilation and in outdoor air. The phylogenetic diversity of airborne bacterial communities was lower indoors than outdoors, and mechanically ventilated rooms contained less diverse microbial communities than did window-ventilated rooms. Bacterial communities in indoor environments contained many taxa that are absent or rare outdoors, including taxa closely related to potential human pathogens. Building attributes, specifically the source of ventilation air, airflow rates, relative humidity and temperature, were correlated with the diversity and composition of indoor bacterial communities. The relative abundance of bacteria closely related to human pathogens was higher indoors than outdoors, and higher in rooms with lower airflow rates and lower relative humidity. The observed relationship between building design and airborne bacterial diversity suggests that we can manage indoor environments, altering through building design and operation the community of microbial species that potentially colonize the human microbiome during our time indoors.

Engineering Crystal Facet of α-MnO2 Nanowire for Highly Efficient Catalytic Oxidation of Carcinogenic Airborne Formaldehyde

Abstract: The activity of exposed crystal facets directly determines its physicochemical properties. Thus, acquiring a high percentage of reactive facets by crystal facet engineering is highly desirable for improving the catalytic reactivity. Herein, single-crystalline α-MnO2 nanowires with major exposed high-index {310} facets were synthesized via a facile hydrothermal route with the assistance of a capping agent of oxalate ions. Comparing with two other low-index facets ({100} and {110}), the resulting α-MnO2 nanowires with exposed {310} facets exhibited much better activity and stability for carcinogenic formaldehyde (HCHO) oxidation, making 100% of 100 ppm of HCHO mineralize into CO2 at 60 °C, even better than some Ag supported catalysts. The density functional theory (DFT) calculations were used to investigate the difference in the catalytic activity of α-MnO2 with exposed {100}, {110}, and {310} facets. The experimental characterization and theoretical calculations all confirm that the {310} facets with high ...