Total Airborne Bacteria Research Articles

Enhancing indoor air quality and cardiopulmonary health in patients with asthma by photocatalytic oxidation and filters air cleaner

BackgroundAir purifiers can enhance indoor air quality and health outcomes, and studies have primarily focused on filters and particulate matter (PM) in households. Photocatalytic oxidation (PCO) is a promising technique for eliminating gaseous pollutants and bioaerosols. However, no field study was conducted in household. Therefore, this study evaluated the effects of the PCO and PCO + filters intervention on indoor air pollutants and cardiopulmonary endpoints in households. MethodsA randomized, double-blind crossover clinical trial was conducted. Indoor air pollutants, including PM, bioaerosols, and gaseous pollutants and cardiopulmonary endpoints including lung function, fractional exhaled nitric oxide (FeNO), respiratory symptoms, and blood pressure were assessed before and after intervention. FindingsThis was the first study to evaluate the effects of PCO and PCO + filters interventions on indoor air pollutants and cardiopulmonary health in households. Indoor total volatile organic compounds (TVOC) and sulfur dioxides (SO2) significantly reduced after PCO intervention, however, we also observed the significant reduction in percentage of predicted values of forced vital capacity (FVC%) and forced expiratory volume in 3 s (FEV3%) and increased in FeNO after 13 days of PCO intervention. The PCO + filters intervention significantly reduced the levels of indoor PM1, PM2.5, PM4, PM10, total suspended particulate matter, ultrafine particles, airborne bacteria, fungi, endotoxin, mites, TVOC, nitrogen dioxide, and SO2, and marginal reduction in carbon monoxide. However, indoor carbon dioxide significantly increased after PCO/PCO + filters intervention. As for cardiopulmonary health, FVC%, and FEV1 % marginally increased 7 days after the PCO + filters intervention.

A Comparative Study: Indoor Air Quality (PM<sub>10</sub>, Ammonia, Airborne Total Bacteria) in Different Types of Broiler Chicken Farm

A Comparative Study: Indoor Air Quality (PM<sub>10</sub>, Ammonia, Airborne Total Bacteria) in Different Types of Broiler Chicken Farm

Environmental factors and particle size shape the community structure of airborne total and pathogenic bacteria in a university campus.

Given the dense population on university campuses, indoor and outdoor airborne bacterial contamination may lead to the rapid spread of diseases in a university environment. However, there are few studies of the characteristics of airborne and pathogenic bacterial communities in different sites on a university campus. In this study, we collected particulate matter samples from indoor and outdoor locations at a university in Bengbu City, Anhui Province, China, and analyzed the community characteristics of airborne and pathogenic bacteria using a high-throughput sequencing technique. The results showed that the composition of the dominant airborne and pathogenic bacterial communities was consistent among sites at the phylum and genus levels, with differences in their relative abundance. There were significant differences in the structure of the airborne and pathogenic bacterial communities between indoor and outdoor sites (p < 0.05). An analysis of similarities (ANOSIM) indicated that the structure of airborne bacterial communities in indoor sites was influenced by the room occupancy rate, ventilation conditions, and the extent of indoor furnishing (p < 0.05), while the structure of pathogenic bacterial communities was influenced by the number of individuals and spatial dimensions (p < 0.05). The impact of particle size on the structure of airborne and pathogenic bacterial communities was relatively minor. A total of 194 suspected pathogenic bacterial species were identified, accounting for 0.0001-1.3923% of the total airborne bacteria, all of which were conditional pathogens. Among them, Saccharopolyspora rectivirgula, Acinetobacter johnsonii, and Moraxella osloensis exhibited relatively high relative abundance, accounting for 24.40, 16.22, and 8.66% of the total pathogenic bacteria, respectively. Moreover, 18 emerging or re-emerging pathogenic bacterial species with significant implications for human health were identified, although their relative abundance was relatively low (0.5098%). The relative abundance of pathogenic bacteria in indoor environments was significantly higher than outdoors, with the laboratory and dormitory having the highest levels. The findings of this study provide valuable guidance for the prevention and control of airborne bacterial contamination and the associated health risks in both a campus environment and other public spaces with high occupancy rates.

Assessment of airborne bacteria in the indoor of public-use facilities concentrated on influencing factors and opportunistic pathogenic bacteria

For public-use facilities in urban centers with high occupancy, it is imperative to effectively manage opportunistic pathogenic bacteria due to the diverse range of users, including the immunocompromised population, such as the elderly, children. Therefore, we investigated the concentration of airborne bacteria at several public-use facilities in urban centers in South Korea. The level of total airborne bacteria in the facilities was positively correlated with user density and CO2 levels. Notably, subway compartments demonstrated particularly high levels of airborne bacteria. Subway compartments and daycare centers contained opportunistic pathogenic bacteria associated with antibiotic resistance. The relative abundance of genera associated with these species showed minor differences by season and facility; the genera Klebsiella and Staphylococcus showed high relative abundance in subway compartments and daycare centers, respectively. Based on our findings, we recommend enhancing management strategies targeting opportunistic pathogenic bacteria related to antibiotic resistance in the air of subway compartments and daycare centers.

Spatial distribution of airborne bacterial communities in caged poultry houses

ABSTRACT Microbial aerosols in intensive broiler houses whose species and concentrations are closely related to human health are ubiquitous. Based on 16S rRNA gene sequencing, the aim of this study was to investigate the spatial distribution and diversity of bacterial aerosols in the air of broiler houses. Significant spatial variations in airborne bacterial concentrations were observed inside the poultry farmhouse. The results indicated that bacteria in the air samples could be grouped into a total of 1,674 OTUs. Alpha diversity analysis showed that the diversity of the microbial community at the entry of the broiler house was higher than that at the middle or the rear (p < 0.01). The Sankey diagram illustrated species dynamic changes in Proteobacteria, Firmicutes, and Actinobacteria among the different locations. From the aspect of LEfSe (LDA Effect Size) analysis, we discovered that the abundance of Planctomycetes was significantly higher in the entry than in the rear and middle. This study shows the spatial distribution of the entire bacterial community in intensive broiler houses, which offers a new perspective for studying airborne total bacteria in those environments. Implications: The bacteria contained in air aerosols from poultry houses are closely connected to animal health and production. This study aimed to investigate the spatial distribution and diversity of bacterial aerosols in the air of broiler houses. The results observed that bacterial aerosol concentrations in the examined broilers house varied greatly at different positions, and a significantly higher exposure to bacterial aerosol was observed at the middle than at the other positions (p < 0.05). The alpha diversity analysis showed that the diversity of the microbial community at the entry of the broiler house was higher than that at the middle or the rear (P<0.01). Sankey diagram illustrated species dynamic changes of Proteobacteria, Firmicutes and Actinobacteria among the different locations. The microbial communities in genus level in the samples of entry and rear were closer, while the species diversity of middle and rear samples in chicken house was highly similar (P>0.05). Altogether, results revealed that the effects of spatial factors on the diversity and abundance of bacteria in the air of closed-cage broiler houses, which poses a potential threat to the health of animals and workers in those environments.

East Asian monsoon manipulates the richness and taxonomic composition of airborne bacteria over China coastal area

Airborne bacteria may have significant impacts on aerosol properties, public health and ecosystem depending on their taxonomic composition and transport. This study investigated the seasonal and spatial variations of bacterial composition and richness over the east coast of China and the roles of East Asian monsoon played through synchronous sampling and 16S rRNA sequencing analysis of airborne bacteria at Huaniao island of the East China Sea (ECS) and the urban and rural sites of Shanghai. Airborne bacteria showed higher richness over the land sites than Huaniao island with the highest values found in the urban and rural springs associated with the growing plants. For the island, the maximal richness occurred in winter as the result of prevailing terrestrial winds controlled by East Asian winter monsoon. Proteobacteria, Actinobacteria and Cyanobacteria were found to be top three phyla, together accounting for 75 % of total airborne bacteria. Radiation-resistant Deinococcus, Methylobacterium belonging to Rhizobiales (related to vegetation) and Mastigocladopsis_PCC_10914 originating from marine ecosystem were indicator genera for urban, rural and island sites, respectively. The Bray-Curits dissimilarity of taxonomic composition between the island and two land sites was the lowest in winter with the representative genera over island also typically from the soil. Our results reveal that seasonal change of monsoon wind directions evidently affects the richness and taxonomic composition of airborne bacteria in China coastal area. Particularly, prevailing terrestrial winds lead to the dominance of land-derived bacteria over the coastal ECS which may have a potential impact on marine ecosystem.

A Study on the Distribution Characteristics of Formaldehyde, Volatile Organic Compounds, Particulate Matter, and Airborne Bacteria in Indoor Play Centers

This study aimed to evaluate the indoor air quality differences at 19 indoor play centers of cafés and play areas in Gyeonggi-do where were 430 m&lt;sup&gt;2&lt;/sup&gt; or larger. We examined concentrations of formaldehyde (HCHO), volatile organic compounds (VOC), particulate matter, and total airborne bacteria, and how their distributions varied with the number of visitors at the places. On weekdays, there were no statistically significant differences in mean indoor air pollutant concentrations between the cafés and play areas at 95% confidence intervals. However, significant differences were observed on weekends when the number of visitors increased. HCHO concentrations increased up to 159%, and VOC concentrations increased up to 210%. A higher increase rate of HCHO occurred at the cafés compared to the play areas since cooking operations were performed under natural ventilation. The PM10 concentration increased by approximately 33.2%, with an increase of 49.2% in the play areas and a 18.3% increase in the cafés on weekends. PM&lt;sub&gt;2.5&lt;/sub&gt; concentration particularly increased during weekends in the cafés and play areas by 113% and 63.6%, respectively. During cooking operations, the concentration of gaseous and particulate pollution increased more in the air pollutant concentration of cafés, and the overall bacterial concentration increased during weekends due to higher numbers of visitors. Therefore, indoor play centers with cooking operations require adequate air quality management to mitigate the indoor pollution.

Quantification of antibiotic resistance genes (ARGs) in clouds at a mountain site (puy de Dôme, central France)

Antibiotic resistance in bacteria is becoming a major sanitary concern worldwide. The extensive use of large quantities of antibiotics to sustain human activity has led to the rapid acquisition and maintenance of antibiotic resistant genes (ARGs) in bacteria and to their spread into the environment. Eventually, these can be disseminated over long distances by atmospheric transport. Here, we assessed the presence of ARGs in clouds as an indicator of long-distance travel potential of antibiotic resistance in the atmosphere. We hypothesized that a variety of ARGs can reach the altitude of clouds mainly located within the free troposphere. Once incorporated in the atmosphere, they are efficiently transported and their respective concentrations should differ depending on the sources and the geographical origin of the air masses. We deployed high-flow rate impingers and collected twelve clouds between September 2019 and October 2021 at the meteorological station of the puy de Dôme summit (1465 m a.s.l., France). Total airborne bacteria concentration was assessed by flow cytometry, and ARGs subtypes of the main families of antibiotic resistance (quinolone, sulfonamide, tetracycline; glycopeptide, aminoglycoside, β-lactamase, macrolide) including one mobile genetic element (transposase) were quantified by qPCR. Our results indicate the presence of 29 different ARGs' subtypes at concentrations ranging from 1.01 × 103 to 1.61 × 104 copies m−3 of air. Clear distinctions could be observed between clouds in air masses transported over marine areas (Atlantic Ocean) and clouds influenced by continental surfaces. Specifically, quinolones (mostly qepA) resistance genes were prevalent in marine clouds (54 % of the total ARGs on average), whereas higher contributions of sulfonamide, tetracycline; glycopeptide, β-lactamase and macrolide were found in continental clouds. This study constitutes the first evidence for the presence of microbial ARGs in clouds at concentrations comparable to other natural environments. This highlights the atmosphere as routes for the dissemination of ARGs at large scale.

Correlation of animal-based parameters with environment-based parameters in an on-farm welfare assessment of growing pigs

Nine pig farms were evaluated for the welfare quality in Korea using animal- and environment-based parameters (particularly air quality parameters) during the winter of 2013. The Welfare Quality® (WQ®) protocol consists of 12 criteria within four principles. The WQ® protocol classifies farms into four categories ranging from ‘excellent’ to ‘not classified’. Each of these criteria has specific measures for calculating scores. Calculations for the welfare scores were conducted online using the calculation model in the WQ® protocol. Environment-based parameters like microclimate (i.e., temperature, relative humidity, air speed, and particulate matter), bacteria (total airborne bacteria, airborne total coliform, and airborne total Escherichia coli), concentration of gases (carbon dioxide, ammonia, and hydrogen sulfide) were measured to investigate the relationship between animal- and environment-based parameters. Correlations between the results of animal- and environment-based parameters were estimated using spearman correlation coefficient. The overall assessments found that five out of nine farms were ‘acceptable’, and four farms were ‘enhanced’; no farm was ‘not classified’. The average score for the four principles across the nine farms, in decreasing order, were ‘good feeding’ (63.13 points) > ‘good housing’ (59.26 points) > ‘good health’ (33.47 points) > ‘appropriate behaviors’ (25.48 points). In the result of the environment aspect, the relative humidity of farms 2 (93.4%), 3 (100%), and 9 (98%) was much higher than the recommended maximum relative humidity of 80%, and four out of the nine farms had ammonia concentrations greater than 40 ppm. Ammonia had negative correlations with ‘positive social behaviors’ and positive emotional states: content, enjoying, sociable, playful, lively, happy and it had positive correlations with negative emotional states: aimless, distressed. The concentration of carbon dioxide had negative correlations with positive emotional states; calm, sociable, playful, happy and it had a positive correlation with negative emotional state; aimless. Our results indicate that the control of the environment for growing pigs can help improve their welfare, particularly via good air quality (carbon dioxide, ammonia, hydrogen sulfide).

광주지역 취약계층시설 실내공기 중 유해물질 농도 조사

This research was conducted to quantify hazardous substances in indoor air from various public facilities with sensitive populations, including daycare centers, medical institutions, and elderly care facilities from March 2021 to October 2021, located in Gwangju city, South Korea. Measured air pollutants include: PM<SUB>10</SUB>, PM<SUB>2.5</SUB>, CO₂, CO, total airborne bacteria(TAB), 43 different volatile organic compounds(VOCs), and 7 different aldehydes. The measured air pollutants were found in the following average concentrations 18.3 μg/m³ of PM<SUB>10</SUB>, 11.7 μg/m³ of PM<SUB>2.5</SUB>, 596 ppm of CO₂, 18.7 μg/m³ of formaldehyde, 0.9 ppm of CO, and 212 CFU/m³ of TAB. The average VOCs concentrations of toluene, m,p-xylene, ethylbenzene, styrene, o-xylene were 37.8 μg/m³, 12.7 μg/m³, 10.0 μg/m³, 4.9 μg/m³, 4.7 μg/m³, respectively. d-limonene, 1-butanol, octane, heptane, butyl acetate, and hexane were also detected. The average total volatile organic compounds(TVOCs) concentration was found to be 293.8 μg/m³ for daycare centers, 357.4 μg/m³ for medical institutions and 262.9 μg/m³ for elderly care facilities. For aldehydes, formaldehyde and acetaldehyde concentrations were 18.7 μg/m³ and 12.4 μg/m³, respectively.

Role of Bioaerosols on the Short-Distance Transmission of Multidrug-Resistant Methicillin-Resistant Staphylococcus aureus (MRSA) in a Chicken Farm Environment.

Methicillin-resistant Staphylococcus aureus (MRSA) is a dynamic and tenacious pathogenic bacterium which is prevalent in livestock farming environments. This study investigated the possibility of MRSA spread via bioaerosol transmission from an indoor chicken farm environment to outdoors downwind (up to 50 m). The concentration of total airborne bacteria colony formation units (CFUs) was decreased with increasing sampling distance ranging from 9.18 × 101 to 3.67 × 103 per air volume (m3). Among the 21 MRSA isolates, 15 were isolated from indoor chicken sheds and exposure square areas, whereas 6 were isolated from downwind bioaerosol samples. Molecular characterization revealed that all of them carried the staphylococcal cassette chromosome mec (SCCmec) VIII, and they were remarkably linked with the hospital-associated MRSA group. Spa typing analysis determined that all MRSA isolates belonged to spa type t002. Virulence analysis showed that 100% of total isolates possessed exfoliative toxin A (eta), whereas 38.09% and 23.80% strains carried exfoliative toxin B (etb) and enterotoxin A (entA). Additionally, all of these MRSA isolates carried multidrug resistance properties and showed their resistance against chloramphenicol, ciprofloxacin, clindamycin, tetracycline, and erythromycin. In addition, chi-squared statistical analysis displayed a significant distributional relationship of gene phenotypes between MRSA isolates from chicken farm indoor and downwind bioaerosol samples. The results of this study revealed that chicken farm indoor air might act as a hotspot of MRSA local community-level outbreak, wherein the short-distance dispersal of MRSA could be supported by bioaerosols.

On-Site Investigation of Airborne Bacteria and Fungi According to Type of Poultry Houses in South Korea

A field survey was conducted to quantify indoor exposure levels and emission rates of airborne microorganisms generated from domestic poultry buildings. There were three types of poultry buildings (caged layer house, broiler house, and layer house with manure belt), classified by the mode of manure treatment and ventilation, investigated in this study. Nine sites for each poultry building were selected and visited for measuring the exposure level and emission rate of airborne microorganisms. The total number of airborne bacteria and fungi among the airborne microorganisms were analysed based on the incubation method. Their emission rates were estimated by dividing the emission amount, which was calculated through multiplying indoor concentration (cfu/m3) by ventilation rate (m3/h), into the indoor area (m2) and the number of poultries reared in the poultry building. The mean exposure levels of the total airborne bacteria and fungi in the poultry building were 7.92 (SD: 2.66) log (cfu m−3) and 4.92 (SD: 1.79) log (cfu m−3), respectively. Emission rates of airborne microorganisms in poultry buildings were estimated to be 0.263 (±0.088) log (cfu hen−1h−1) and 0.839 (±0.371) log (cfu m−2h−1) for total airborne bacteria, and 0.066 (±0.031) log (cfu hen−1h−1) and 0.617 (±0.235) log (cfu m−2h−1) for total airborne fungi. The distribution patterns of the total airborne bacteria and fungi were similar regardless of poultry building type. Among poultry buildings, the broiler house showed the highest exposure level and emission rate of total airborne bacteria and fungi, followed by the layer house with manure belt and the caged layer house (p &lt; 0.05). The finding that the broiler house showed the highest exposure level and emission rate of airborne microorganisms could be attributed to sawdust, which can be dispersed into the air by the movement of the poultry when it is utilized as bedding material. Thus, a work environmental management solution for optimally reducing airborne microorganism exposure is necessary for the broiler house.

Concentrations, Size Distribution, and Community Structure Characteristics of Culturable Airborne Antibiotic-Resistant Bacteria in Xinxiang, Central China

Antimicrobial resistance is considered an important threat to global health and has recently attracted significant attention from the public. In this study, the concentrations and size distribution characteristics of culturable airborne total bacteria (TB) and four antibiotic-resistant bacteria (tetracycline-resistant bacteria (TRB), ciprofloxacin-resistant bacteria (CRB), erythromycin-resistant bacteria (ERB), and ampicillin-resistant bacteria (ARB)) were investigated for approximately one year to explore their variations under different seasons, diurnal periods, and air quality levels. The concentrations of TB and four antibiotic-resistant bacteria in winter and night were higher than during other seasons and diurnal periods. Their maximum concentrations were detected from air under moderate pollution or heavy pollution. PM2.5, PM10, SO2, and NO2 were positively related to TB and four antibiotic-resistant bacteria (p &lt; 0.01), whereas O3 and wind speed were negatively related to them (p &lt; 0.05). The particle size of TB and four antibiotic-resistant bacteria were mainly distributed in stage V (1.1–2.2 µm). Bacillus was the dominant genus of ARB (75.97%) and CRB (25.67%). Staphylococcus and Macrococcus were the dominant genera of TRB (46.05%) and ERB (47.67%), respectively. The opportunistic pathogens of Micrococcus, Sphingomonas, Enterococcus, Rhodococcus, and Stenotrophomonas were also identified. This study provides important references for understanding the threat of bioaerosols to human health.

Seasonal variations of microbes in particulate matter obtained from Dhaka City in Bangladesh

ABSTRACT The present study, for the first time, evaluated the seasonal variation of PM10-associated bacterial and fungal concentrations at four locations (CARS premises, Doyel Chattar, Postogola, and Chittagong Road) in Dhaka, Bangladesh. In this study, PM10 samples were collected four times on 20.3 × 25.4 cm irradiated glass fibre filter from November 2018 to August 2019. The concentrations of total airborne bacteria (14,073 ± 8,897 CFU/m3) were found to be significantly higher (one-way ANOVA; p < 0.05) in Chittagong Road, which is known for traffic congestion, than that of the other locations. The total airborne bacterial concentrations occurred in the following descending order: winter>spring>summer>rainy. Bacillus spp. and Staphylococcus spp. were found to be the dominant species present in PM10 particles. Based on Pearson correlation analysis and stepwise multiple-regression analysis, relative humidity was found to be the most important variable controlling the concentrations of total airborne bacteria. Common fungi such as Aspergillus, Penicillium, Cladosporium and Fusarium genera were identified in the PM10 samples. The highest fungal concentration (1,974 ± 1,173 CFU/m3) was found at Chittagong Road. The total fungal spore concentrations occurred in the following descending order: summer>spring>winter>rainy. From correlation analysis and stepwise regression analysis, the temperature was found to be the most important variable influencing the concentrations of fungi in PM10 samples. A dose-rate estimation study revealed that the children were more vulnerable compared to adults with respect to exposure to bacterial and fungal dose rates. The present study has enormous implications considering the health hazards the bacterial and fungal communities pose to humans.

Factors affecting the exposure to physicochemical and microbiological pollutants in vehicle cabins while commuting in Lisbon.

Commuters are exposed to a variety of physicochemical and microbiological pollutants that can lead to adverse health effects. This study aims to evaluate the indoor air quality (IAQ) in cars, buses and trains in Lisbon, to estimate inhaled doses while commuting and to evaluate the impacts of cleaning and ventilation on the IAQ. Particulate matter with diameter lower than 1, 2.5 and 10μm (PM1, PM2.5 and PM10), black carbon (BC), carbon monoxide (CO), carbon dioxide (CO2) volatile organic compounds (VOCs), formaldehyde (CH2O) and total airborne bacteria and fungi were measured and bacterial isolates were identified. Results showed that the type of ventilation is the main factor affecting the IAQ in vehicle cabins. Under the fan off condition, the concentration of BC was lower, but the concentration of gases such as CO2, CO and VOC tended to accumulate rapidly. When the ventilation was used, the coarse particles were filtered originating the decrease of indoor concentrations. Commuters travelling in trains received the lowest dose for all chemical pollutants, except VOC, mainly because railways are further away from the direct vehicular emissions. Commuters travelling in cars without ventilation received the highest inhaled dose for almost all pollutants despite having the lowest travel duration. Airborne microbiota was highly affected by the occupancy of the vehicles and therefore, the fungi and bacterial loads were higher in trains and buses. Most of the isolated species were human associated bacteria and some of the most abundant species have been linked to respiratory tract infections.

Temporal discrepancy of airborne total bacteria and pathogenic bacteria between day and night

As the most abundant microbes in the atmosphere, airborne bacteria are closely involved in affecting human health, regional climate and ecological balance. The mobility of airborne microorganisms makes it necessary to study the community dynamic in short cycle. Nevertheless, it remains obscure how the airborne bacteria especially the pathogenic bacteria vary on the small time scale of day and night. To investigate the nycterohemeral discrepancy of airborne total bacteria and pathogenic bacteria, PM2.5 samples were collected in Hangzhou between day and night. Microbial taxonomic information was obtained through 16S rRNA gene sequencing and “human pathogens database” screening. Further analyses based on Multiple Regression Matrices (MRM) approach and Concentration Weighted Trajectory (CWT) model were conducted to elucidate the effect of local environmental factors and long-range transport. The community composition of total bacteria tended to be similar in the daytime while pathogenic bacteria turned out to be homogeneous in the nighttime. To be vigilant, the diversity of airborne pathogenic bacteria echoed the frequency of anthropogenic activities with the pathogen inhalation rate roughly at 428 copies/h and 235 copies/h respectively in daytime and nighttime. The nycterohemeral discrepancy of total bacteria was principally driven by the filtering of environmental factors, i.e., CO and NO2, indicating that anthropogenic activities brought about the homogeneity. Airborne pathogenic bacteria coupled with the strong resistances of environmental filtering stood out from their non-pathogenic counterpart, which enabled the long-range transport. Indeed, the nycterohemeral discrepancy of pathogenic bacteria was shaped by the transport of air masses. This research filled the gaps in temporal variance of airborne microorganisms on the small time scale of day and night, providing crucial foundation for precisely predicting ecological and health effects of bioaerosols.

A field study on the indoor air quality of wooden welfare facilities in Korea

The rapid economic growth in the East Asian region has particularly raised the issue of air quality. Indoor Air Quality (IAQ) has also become an important research topic in the building environment. Indoor air pollutants are harmful to human health and are especially dangerous to vulnerable populations, such as elderly people and children. Wood interior remodelling can protect people’s health from indoor air pollutants and wood is and eco-friendly and sustainable building material with low thermal conductivity and humidity control. This study measured the IAQ of twelve welfare facilities in Korea which renovated the interior with wood materials to improve indoor air quality. In this study, twelve IAQ factors were measured as follows. Comfort factors (Temperature and Relative humidity), particulate matter, biological pollutants, air borne asbestos fibers, and chemical pollutants (carbon dioxide, formaldehyde, Volatile Organic Compounds, radon, ozone, nitrogen oxide and carbon monoxide). As a result, the measured value of the indoor air quality factors for 12 welfare facilities is as follows. The average particulate matter was less than 12μg/m3, the average of carbon dioxide was 754.2ppm, the formaldehyde was 46μg/m3, the volatile organic compounds was 335μg/m3, the total airborne bacteria was 37.8 CFU/m3and the radon was 59.5Bq/m3.

Microbiological air quality in free-farrowing housing systems for sows

This study investigates air hygienic characteristics of housing systems without fixation for lactating sows, with a focus on microbiological air quality. For animal welfare considerations, free-farrowing systems have been developed to replace those with farrowing crates (FC) and are currently available on the market. A group housing system (GH) for six lactating sows, a single loose-housing system (LH), and a conventional system with FC were tested. By maintaining similar management conditions, microbiological air quality was examined in eight batches with 148 farrowings in total with samplings at the beginning, in the middle, and at the end of the occupancy period of 33 days. No significant differences between the systems were observed in the concentration of total airborne bacteria (TAB), haemolytic streptococci (HS), molds, or yeasts. However, the concentrations of TAB and HS increased significantly over time. Additionally, significant correlations were detected for LH and FC between TAB and HS, and between TAB and carbon dioxide; significant correlations between TAB and inside temperature and total animal weight were revealed only in GH. Significant correlations between TAB and both the dust and inside humidity parameters were found only in FC. Given these results, it was shown that the free-farrowing systems used here do not necessarily lead to poorer microbiological air quality.

English

There is presently no information on the occurrence, abundance and diversity of airborne bacteria in Botswana hospitals. There is also growing concern in the global spread of antibiotic resistant bacteria that continue to emerge and pose serious challenge to human health. This study was aimed at determining the occurrence, relative abundance and diversity of airborne bacterial species and their antibiotic resistance patterns. Correlation between the meteorological conditions and the bacterial concentrations was also determined. Air impaction method was applied for the collection of airborne bacteria on selective media, antibiotic resistance was determined by screening isolates for resistance phenotypes and polymerase chain reaction (PCR) was applied for detection of resistance genes to clinically relevant antibiotics. The assessment of total airborne bacteria in hospital units revealed high abundance of airborne bacteria in paediatric wards than in the operating theatres. The highest bacterial concentrations were observed at the paediatric wards in Palapye (PPH; 7.9 &times; 102 CFU/m3), Maun (LMH; 6.4 &times;102 CFU/m3) and Francistown (NRH; 5.8 &times;102 CFU/m3). Diverse airborne bacterial species were observed with high concentration recorded for Pseudomonas species in all three hospitals&rsquo; units. The frequency of antibiotic resistance genes detected in bacterial isolates were; dfr1 (36%), mph(A) (26%), ermC (12%), strB (10%) and intI1 (16%). The study provide evidence suggesting air in hospitals&rsquo; units as a hotspot for potentially pathogenic bacteria and antibiotic resistance genes, hence the need to develop surveillance tools for monitoring the movement of airborne bacteria in hospitals in order to mitigate possible spread of nosocomial infections. &nbsp; Key words: Airborne bacteria, antibiotic resistance genes, operating theatre, paediatric, human health.

Field study on indoor air quality of wood remodeled welfare facilities for physical and psychological benefits

Outdoor pollutants are well documented and monitored due to existing air quality regulations in many parts of the world. However, as information regarding indoor air quality is still limited, there are not enough information for indoor air pollutants. Indoor air quality pollutants are harmful to human health and are especially dangerous to vulnerable populations, such as elderly people and children. The effects of indoor environment and indoor air pollutants on children and the elderly are being studied worldwide. Ultimately, this paper highlights the prospect of remodeling wood interior, an indoor air pollutants reduction strategy that will help improve indoor air quality and public health. Wood is an environmentally friendly building material with low thermal conductivity and humidity control, and wood interior remodeling can protect people's health from indoor air pollutants. In this paper, twelve indoor air quality factors were measured: comfort factor (temperature and relative humidity), particulate matter, biological pollutants (total airborne bacteria), Airborne asbestos fibers, and chemical pollutants (carbon monoxide and dioxide, formaldehyde, volatile organic compounds, radon, ozone and nitrogen oxides). The average value of the indoor air quality factors for 12 welfare facilities is as follows. The average particulate matter was less than 12μg/㎥, the average of carbon dioxidewas 754.2 ppm, the formaldehyde was 46.6μg/㎥, the volatile organic compounds was 335.0μg/㎥, the total airborne bacteria was 37.8 CFU/㎥and the radon was 59.5Bq/㎥. As a result, almost all of the measurement locations were found to satisfy the international indoor air quality guidelines. It is thus judged that interior remodeling using wood can improve the indoor air quality of welfare facilities, and that it is necessary to constantly measure indoor air quality for accurate indoor air quality analysis.