#covidisairborne: produção e circulação de evidências sobre a transmissão da covid-19 / #covidsairborne: production and circulation of evidence on covid-19 transmission

Esta tese investiga a produção e circulação de evidências científicas sobre a transmissão do SARS-CoV-2, com ênfase no debate científico em torno da transmissão viral por aerossóis e a implicação de diferentes entendimentos nas práticas de prevenção adotadas ao redor do mundo. De cunho etnográfico, a pesquisa foi conduzida a partir da hashtag #covidisairborne, de importante repercussão entre cientistas e ativistas na rede social Twitter, e analisou diversos materiais digitais como artigos científicos, entrevistas, newsletters e tuítes publicados sobre o tema na rede conforme circulavam no campo, além de acompanhar o trabalho de um laboratório de pesquisa em aerossóis. A chegada da covid teria intensificado a disputa em torno das formas de transmissão viral, transformando-a em questão pública com repercussão nas práticas de proteção disseminadas durante a pandemia. Diante das evidências científicas relacionadas à transmissão, os fatos científicos se apresentam de forma contextual e implicada em distintos discursos e intenções para a condução da crise sanitária. A pandemia de covid teria acelerado o reconhecimento da qualidade do ar interno como um problema de saúde pública que chama a atenção para o ar que respiramos, e as estratégias para a mitigação dos riscos associados ao "novo normal" precisam ser informadas por princípios de justiça social e direito à saúde. (AU)

This work investigates the production and circulation of scientific evidence on the transmission of SARS-CoV-2, with an emphasis on the scientific debate surrounding aerosol viral transmission and the implications of different understandings in prevention practices adopted around the world. Ethnographically driven, the research was conducted from the hashtag #covidisairborne, which had significant repercussion among scientists and activists on the social media platform Twitter, and analyzed various digital materials such as scientific articles, interviews, newsletters, and tweets published on the network as they circulated in the field, as well as following the work of an aerosol research laboratory. The advent of covid is said to have intensified the dispute over the modes of viral transmission, turning it into a public issue with repercussions on the disease prevention practices disseminated during the pandemic. In the face of scientific evidence related to transmission, scientific facts present themselves in a contextual manner and are implicated in different discourses and intentions for managing the health crisis. The covid pandemic is said to have accelerated the recognition of indoor air quality as a public health issue that draws attention to the air we breathe, and strategies for mitigating risks associated with the "new normal" need to be informed by principles of social justice and the right to health. (AU)

Wind-driven roof turbines' effectiveness in enhancing household ventilation: a potential tool to reduce tuberculosis infection

Background: South Africa's overburdened healthcare systems have led to criticism of its unsustainable tuberculosis management interventions. In 2011, the National Department of Health implemented an outpatient, decentralised care model, but this increased costs and jeopardised the long-term viability of prevention measures. Home confinement is now recognised as a viable intervention option, when combined with safety precautions such as ventilation and medical support. However, little is known about the risk of infection in this context. Objectives: To assess the effectiveness of wind-driven roof turbines in enhancing ventilation and their potential to lower the risk of Mycobacterium tuberculosis infection in a residential setting. Methods: Eight houses were selected and divided equally into intervention (wind turbines installed) and control groups, using a pairwise comparison method. The CO2 decay method was used as a proxy to determine ventilation in the houses. The wind-driven roof turbines' potential to lower the risk of Mycobacterium tuberculosis infection was stochastically evaluated using the Wells-Riley mathematical model. Results: During two seasons, installation of a roof turbine resulted in twofold ventilation rates compared to the control houses. Consequently, the WellsRiley model predicted a twofold reduction in the probability of infection in the intervention compared to the control households. Conclusion: Low-cost, low-maintenance wind-driven roof turbines are effective in increasing ventilation in houses, and should be considered as an additional layer of protection against Mycobacterium tuberculosis and other infections in residential settings.

Indoor Air Quality Assessment in the Office of the Transformer Manufacturing Factory in Selangor, Malaysia

@#Introduction: As humans spend 90% of their time inside, indoor air quality (IAQ) is critical for occupant health. The primary concern associated with low IAQ is its impact on employees’ health, comfort, and productivity. In accordance with the Industry Code of Practice on Indoor Air Quality 2010 (ICOP IAQ 2010), a ten-parameter assessment was conducted in the office of the transformer manufacturing factory in Selangor, Malaysia. Methods: The measured parameters are temperature, air movement, relative humidity, carbon dioxide (CO2 ), carbon monoxide (CO), formaldehyde (CH2 O), particulate matter (PM10), total volatile organic compounds (TVOCs), total fungal count (TFC), and total bacterial count (TBC). This study employed both qualitative and quantitative approaches by distributing questionnaires (N = 42), and measuring the indoor air quality parameters with integrated equipment at selected stations and comparing them to the ICOP IAQ 2010 standard. Results: A majority of the measures, with the exception of air movement, CO2 , and TBC, complied with the ICOP IAQ 2010 standards. The one-way ANOVA test showed that there were significant differences (p < 0.05) for the parameters of temperature, PM10, and TVOCs. The ChiSquare test revealed that sleepiness was a symptom of the sick building syndrome, affecting both male and female employees the most frequently and significantly. Conclusion: Air movement, CO2 , and TBC values that did not meet ICOP IAQ 2010 requirements revealed poor IAQ at the study site, which could have a negative influence on the employees’ health. To cut down on air pollution, the improvement on the ventilation system should be done to reduce the risks to the employees’ health.

Indoor Air Quality Level at Medical Clinics, University Hospital in Klang Valley, Malaysia

@#Introduction: Patient health can be influenced by indoor air quality (IAQ) level, where the risks of IAQ pollution are proportionate with the occupant number in the clinic. This research aims to determine the level of IAQ in Medical Clinic 1 and 2 of University Hospital in Klang Valley, Malaysia. Methods: The indoor exposure to physical (temperature, relative humidity and air movement), chemical (formaldehyde, CO2 , CO, TVOC and PM10) and biological (bacterial and fungal count) parameters following Industry Code of Practice (ICOP) IAQ (2010) were assessed in the morning and afternoon using relevant equipment. Data was analysed with One-Sample T Test and Independent T Test using SPSS Version 25. Results: No statistically significant mean difference (p>0.05) of IAQ parameters between both Medical Clinics (morning & afternoon) except for Rh and CO by Independent T Test analysis. In contrast, the One-Sample T Test showed there was statistically significant mean difference (p<0.01) of all parameters as compared to the ICOP (2010) standard in both Medical Clinics (morning and afternoon). There was a positive correlation of CO2 , CO and formaldehyde with bacterial counts (TBC) for both Medical Clinics. Meanwhile, CH2 O concentration was slightly higher in the morning due to the usage of cleaning products which may have released CH2 O gas killing the bacteria, thus lower the rate of bacterial growth in the afternoon. Fungal counts showed no significant impact. Conclusion: All measured parameters were complied with the ICOP (2010) standard except air movement and CO2 in both Medical Clinics.

Translation and adaptation of the indoor environmental quality questionnaire to Brazilian portuguese

Introduction: Indoor environmental quality (IEQ) impacts well-being, performance, and mental and physical health. A questionnaire for assessing occupants' perception of IEQ was developed in English. This study aimed to translate this instrument into Brazilian Portuguese and adapt it to the Brazilian population.Methods: The translation and adaptation process consisted of forward translation, reconciliation, back translation, back translation review, harmonization, two cognitive debriefings, and finalization.Results: The final translated version included new questions and changed the scale to a visual-analog format. The clarity assessment showed that, after cognitive debriefings, all questions displayed satisfactory scores, with the majority rated higher than 9 on a 0-10 scale.Conclusions: The Brazilian Portuguese version of the IEQ questionnaire is a simple tool that can be employed in biomedical and building research to investigate the association of perceived IEQ with health-related parameters, as well as in architecture, engineering, and management projects. As a next step, a psychometric validation of the instrument will be performed.

Assessment Of Volatile Organic Compound (Vocs) In Multi-Storey Shopping Mall In Malacca Malaysia

@#This study investigates the mall's Indoor Air Quality (IAQ) to compare changes in levels of Volatile Organic Compounds (VOCs) concentration in the morning and evening. It also explores the sources of emission released that could be related to occupants' health status (dizziness, headaches, flu, running nose, nose stuffy, nose irritation, eye irritation, watery eye, and eye reddening). A questionnaire survey approach was used to collect quantitative data involving 32 workers from malls in Malacca, Malaysia. This study established models to measure changes in VOCs level in two different sessions for a given area. Also, predictors related to the work context (human performance and condition) were found to be significantly related to occupants' symptoms. Two significant values identified the changes in VOCs concentration for morning and evening sessions in the lobby, bakery, eye ware shop, mobile centers, and supermarket. No evidence supports the exposure towards the personal individual in the present findings. This study contributes to the literature on levels of VOCs in the shopping mall as well as the emission sources. It also suggests that more comprehensive monitoring can be achieved, particularly in the context of Malaysia.

Exposição ao uso da lenha para cocção no Brasil e sua relação com os agravos à saúde da população / Exposure to the use of firewood for cooking in Brazil and its relation with the health problems of the population

Resumo A poluição do ar em ambientes fechados é agravada pela queima de lenha em fogões rústicos e ambientes pouco ventilados. A exposição aos poluentes emitidos por este tipo de combustível resulta no aumento da morbidade e da mortalidade. No Brasil, os estudos e as estimativas são escassos. Visando entender esta problemática, o objetivo deste trabalho foi investigar o uso de lenha utilizando as séries de dados das agências governamentais para estimar o número de pessoas expostas. Os resultados apontam que a lenha é o segundo combustível mais usado para cozinhar, sendo utilizada por uma parcela significativa da população, em torno de 30 milhões de brasileiros. Um fator decisivo no maior uso deste combustível é o nível socioeconômico da população associada ao preço do gás liquefeito de petróleo (GLP). Os estudos realizados no país registraram concentrações altas de partículas durante a queima da lenha, excedendo os limites sugeridos pela Organização Mundial da Saúde (OMS). Também foram observadas associações entre a exposição aos poluentes gerados pela queima e o agravamento dos mais diversos problemas de saúde, dentre eles doenças respiratórias e câncer. A substituição da lenha e outros combustíveis sólidos por combustíveis mais limpos deve ser a meta do governo para minimizar custos com a saúde.

Abstract Indoor air pollution is exacerbated by the burning of firewood in rustic stoves and poorly ventilated environments. Exposure to the pollutants emitted by this type of fuel results in increased morbidity and mortality. In Brazil, studies and estimates regarding these conditions are scarce. In order to understand this problem, the objective of this work was to investigate the use of firewood using the data series of government agencies to estimate the number of exposed people. The results indicated that firewood is the second most used fuel for cooking, being used by a significant portion of the population, more than 30 million Brazilians. A decisive factor in the increased use of this fuel is the socioeconomic level of the population associated with the price of liquefied petroleum gas (LPG). The studies carried out in the country recorded high concentrations of particles during firewood burning, exceeding the limits suggested by the World Health Organization (WHO). Associations were also observed between the exposure to the pollutants generated by the burning and the aggravation of health problems, among them respiratory diseases and cancer. Replacing fuelwood and other solid fuels with cleaner fuels should be the government's goal to minimize health costs.

Indoor Air Quality in the Hospital: The Influence of Heating, Ventilating and Conditioning Systems

Abstract Clean, fresh air is the most important requirement for good indoor air quality (IAQ) in all buildings, but it is especially important with regard to the environments within hospitals and other healthcare facilities. The literature indicates that buildings with heating, ventilating and air conditioning (HVAC) systems may have an increased risk of sick building syndrome (SBS) and building-related illness (BRI) if they are not well maintained. Microorganisms are brought into hospitals by people, air currents, water, construction materials and equipment. The main objective of this study was to assess the degree of fungal and bacterial contamination in the University Clinical Centre in Banja Luka, which is directly connected to the HVAC system. Airborne bacteria and fungi in the indoor hospital environment were assessed experimentally. Air samples were collected during the winter season. This paper presents the results related to the concentration of microorganisms expressed in colony forming units per cubic metre of air sampled (in CFU/m3) together with the microclimatic parameters temperature and relative humidity. The results of monitoring indicate the effectiveness of HVAC systems in reducing microbiological contamination.

Microbiological Assessment of Selected Laboratories at a Local University in Malaysia / Jurnal Sains Kesihatan Malaysia

@#Microbiological contaminations in the laboratories create not only diagnostic issues but also pose a major health risk to lab users. This study was conducted to determine the airborne microbial contamination in seven selected laboratories (KA, KP, PB, NA, BP, CR and MB) at a local public university in Malaysia and to assess the level of contamination on the contact surfaces of the studied laboratories. Two types of sampling methods were used in this study; passive air sampling and contact surface swab sampling. The total microbial counts were determined using Tryptone Soya agar (bacterial count) and Potato Dextrose agar (fungal count). Results showed that NA laboratory had the highest level of total microbial contamination (20.33 ± 3.35 CFU/cm3 ). Most laboratories had significantly higher (p < 0.05) air fungal contamination level compared to bacterial contaminations except for PB and NA laboratories. Significant differences were observed for airborne bacterial contamination readings between sampling time (during working hours vs after hours) for all laboratories except for BP and CR. Overall, bacterial contamination was the highest for incubator door handles’ samples from MB laboratory with an average reading of 93.00 ± 1.43 CFU/cm2 whereas the highest fungal contamination level was obtained from door knobs and work benches, both from CR laboratory with an average reading of 73.33 ± 6.67 CFU/cm2 and 73.33 ± 0.58 CFU/cm2 respectively. Findings from this study could assist in monitoring the efficacy of the existing laboratory management systems namely on the good laboratory practices including aseptic techniques, care for laboratory hygiene and cross-contamination control practices by the laboratory users to ensure that the microbiological contaminations in the laboratories are minimized.

Level Of Indoor Air Quality Among Malaysian Commuter Users: A Case Study

@#Research on environmental ergonomics of train/commuter is very limited. Thus, this study was conducted with aims to determine the environmental ergonomic of public transport, whether it is in accordance to indoor air quality standard inside women coach cabin train during operations. Although the number of passengers is increasing, some claimed that the indoor air quality for the Malaysian commuter train is uncertain, especially at peak times. Unsatisfactory feedback from some respondents—especially female passengers—will affect other passengers to remain loyal to use this facility as one of the main transportation to reduce the traffic congestion that will be faced if using private vehicles. The study conducted during peak hours on the weekends and the trip took exactly two hours and covered 18 main stations. The measurement devices placed at the centre of the cabin Komuter using Air Quality Meter (AIRFLOW Instrument Model TA465). The main parameters measured were temperature, humidity, and carbon dioxide (CO2). This study also counts the number of passengers riding the train. The results showed that the indoor air quality (AIQ) level of the morning hour will affect passengers’ health more compared to the evening hour (this is due to the CO2 level that has exceeded the safety standard). Morning hour gave higher reading of CO2 (43.8%) and relative humidity (17%) compared to evening hour. Evening hours also showed greater temperature at 3%. The findings can give awareness to the train company to improve the IAQ by installing a suitable ventilation system and can give comfort to the passengers when travelling using Malaysian commuter train The results showed that the indoor air quality (AIQ) level of the morning hour will affect passengers’ health more compared to the evening hour (this is due to the CO2 level that has exceeded the safety standard). Morning hour gave higher reading of CO2 (43.8%) and relative humidity (17%) compared to evening hour. Evening hours also showed greater temperature at 3%. The findings can give awareness to the train company to improve the IAQ by installing a suitable ventilation system and can give comfort to the passengers when travelling using Malaysian commuter train.

Influence of Moxa Smoke on Indoor Air Quality and Strategies for Its Control / 针刺研究

Moxibustion is an effective therapy for treatment of a lot of clinical problems, but the ignited moxa-induced smoke containing harmful substances may bring about indoor air pollution to affect both patients' and medical workers' health. However, there is no standards about controlling indoor air quality (IAQ) for moxibustion rooms in China. In the present study, the authors reviewed newly-published articles about some substances released from moxa smoke as inhalable particles (PM 10 and PM 2.5), formaldehyde, benzene, methylbenzene, xylene, bene[α]pyrene, total volatile organic compounds, CO, CO2, NO, SO2, NH3, O3, etc. some of which affect IAQ. On this account, the authors put forward some strategies for controlling IAQ in moxibustion clinics including setting united safe standards, enhancing ventilation, controlling moxibustion material quality and strengthening scientific research on the safety of moxa smoke control, fully playing the superiority of moxibustion therapy and reducing its unfavorable aspects in clinical practice in the future.

Air Pollutants Exposure and Frequency of Micronuclei (MN) among Primary School Children nearby Industrial Area

@#Introduction: Air pollutants that possessed genotoxic properties have the potential to induce genetic damage. Micronuclei (MN) frequency is used as an indicator for identifying potential genotoxic exposures. A comparative cross-sectional study was carried out among primary school children in a petrochemical industrial area (N=111, Kemaman) and a rural (N=65, Dungun) area in Terengganu. Methods: Validated questionnaires were distributed to obtain the respondents’ socio-demographic data, previous exposure and reported respiratory illness. The frequency of micronuclei was assessed in collected buccal mucosa samples of children. The air monitoring was also carried out at 6 selected schools. Results: Results from the statistical analysis carried out showed significant differences with p=0.001 for all parameters assessed between areas, which included ultrafine particles, UFP (z = -4.842), PM2.5 (z = -10.392), PM10 (z= -11.074) NO2 (z = -11.868), SO2 (z = -5.667), relative humidity (z = -5.587). The MN frequency was statistically significant with PM2.5 (χ2= 17.78, p=0.001) and PM10 (χ2= 15.429, p =0.001). The statistical analysis also showed a significant association between UFP and coughing (PR=2.965, 95% CI=1.069-8.225). The multiple logistic regression analysis showed that the main pollutants influencing MN frequencies were UFP and NO2 with UFP (PR=1.877, 95%CI= 1.174-3.002) and NO2 (PR=1.008, 95%CI= 1.001-1.015). Conclusion: This study demonstrated that exposure to air pollutants may increase the risk of respiratory illness and may induce MN formation among children.

A cross-sectional study into the correlation of common household risk factors and allergic rhinitis in Taiwan's tropical environment

Objective To discuss the effect of lesser-known potential risk factors, such as bedroom showers, on the prevalence of allergic rhinitis. Method A cross-sectional, population-based study was performed using both survey and fungal culturing in southern Taiwan. There were 998 participants enrolled in the survey, and 513 sets of fungal culture obtained. With score for allergic rhinitis (SFAR) more than 7, the patient was defined to have allergic rhinitis. Risks of allergic rhinitis were calculated as odds ratios for various predicted risk factors by logistic regression. Correlation between predicted risk factors and fungal level were examined with linear regression. Results The adjusted odds ratio of frequently using bedroom shower to having allergic rhinitis was 1.572 (95% confidence interval: 1.090–2.265), and 0.962 for people with older age to have AR (95% confidence interval: 0.949–0.976). As to the 24-hour fungal level, the standardized coefficient was 0.254 for frequent use of bedroom shower, and 0.106 for window open hours. Conclusions Use of bedroom shower is a potential risk factor for allergic rhinitis development.

A cross-sectional study into the correlation of common household risk factors and allergic rhinitis in Taiwan's tropical environment

OBJECTIVE@#To discuss the effect of lesser-known potential risk factors, such as bedroom showers, on the prevalence of allergic rhinitis.@*METHOD@#A cross-sectional, population-based study was performed using both survey and fungal culturing in southern Taiwan. There were 998 participants enrolled in the survey, and 513 sets of fungal culture obtained. With score for allergic rhinitis (SFAR) more than 7, the patient was defined to have allergic rhinitis. Risks of allergic rhinitis were calculated as odds ratios for various predicted risk factors by logistic regression. Correlation between predicted risk factors and fungal level were examined with linear regression.@*RESULTS@#The adjusted odds ratio of frequently using bedroom shower to having allergic rhinitis was 1.572 (95% confidence interval: 1.090-2.265), and 0.962 for people with older age to have AR (95% confidence interval: 0.949-0.976). As to the 24-hour fungal level, the standardized coefficient was 0.254 for frequent use of bedroom shower, and 0.106 for window open hours.@*CONCLUSIONS@#Use of bedroom shower is a potential risk factor for allergic rhinitis development.

Indoor Air Quality And Its Association With Respiratory Health Among Preschool Children In Urban And Suburban Area

Indoor air quality (IAQ) has become a major concern nowadays because of the universality of exposure and its potential negative impact on human health especially on children. This study is intended to explore the association between IAQ and the respiratory health among preschool children in urban and suburban area. A cross-sectional comparative study was carried out among Malay preschool children in urban (N= 60, Puchong) and suburban (N=60, Hulu Langat) areas. An indoor air quality assessment was conducted in 12 preschools and 60 houses which include parameters of PM2.5, PM10, VOCs, mold, bacteria, Gram-negative bacteria and physical parameters. A set of standardized questionnaire was distributed to obtain respondents’ background information, exposure history and respiratory health symptoms. Spirometry test was carried out and the data obtained were analyzed to determine the lung function of the respondents. There was a significant difference between IAQ in urban and suburban preschools for all parameters measured (p<0.05). Most of the pollutants were significantly associated with respiratory health symptoms. There was a significant association between the level of indoor pollutants with the lung function abnormalities among the respondents. Even though this study is the first to take Gram-negative bacteria as an indoor air pollutant, the finding also shows that there is a significant association between exposure of Gram-negative bacteria with lung function impairment and higher reported respiratory symptoms among the respondents. The finding concluded that exposures to indoor air pollutants, especially PM2.5 increases the risk of getting lung function abnormality and respiratory health symptoms among respondents.

The impact of indoor air pollution on asthma

Asthma is a common, chronic respiratory disease which is a serious issue for healthcare worldwide. When treating asthma, the main therapeutic goals are to achieve good control of symptoms and to prevent exacerbation. The interaction between genetic predisposition and environmental triggers contributes to the pathophysiology of asthma. In this regard, there is growing public awareness of the risk associated with poor indoor air quality. Because people spend considerable amounts of time every day indoors, it is important to identify and control risk factors in the indoor environment impacting individuals susceptible to asthma for successful treatment and prevention. Along with particulate matter, ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, volatile organic compounds, and second-hand smoke are the most common types of air pollutants encountered indoors. This review highlights epidemiological and experimental data on the role of indoor air pollution in the development and aggravation of asthma. Despite some studies showing significant associations between exposure to indoor air pollution and asthma morbidity, conflicting conclusions are drawn in the literature because of limitations in study design, variation in the methods for assessing exposure, possible confounding factors, and other issues. This review will improve our understanding and facilitate the establishment of a better strategy for asthma management and prevention.

Occupancy Implications On Indoor Air Quality (Iaq) In Selected Primary School Classrooms Around Kuantan, Pahang

@#The effects of children’s exposure on high concentration of airborne pollutants at schools often associated with increased rate of absenteeism, low productivities and learning performances, and development of respiratory problems. Recent studies have found that the presence of occupants in the classroom seems to give major effect towards the elevation of concentration of airborne pollutants in indoors. In order to evaluate and further understand on the significance of occupancy factor on IAQ, this study has been designed to determine and compare the level of selected physical (particulate matter (PM)) and chemical (carbon dioxide (CO2) and temperature) IAQ parameters and biological contaminants via colony forming unit (CFUm-3 ) for bacteria and fungi inside the selected classrooms during occupied and non-occupied period (first objective). The second objective is to describe the possible sources of airborne pollutants inside the classrooms at the selected primary schools around Kuantan, Pahang. Assessments of physical and chemical IAQ were done by using instruments known as DustMate Environmental Dust Detector and VelociCalc® MultiFunction Ventilation Meter 9565.The data were recorded every 30 minutes for 8 hours during schooldays and weekend at the selected sampling point in the classrooms. For microbial sampling, Surface Air System Indoor Air Quality (SAS IAQ) was used to capture the bacteria and fungi. The data obtained were compared with the established standard reference known as the Industrial Code of Practice on Indoor Air Quality (2010) constructed by the Department of Occupational Safety and Health (DOSH), Malaysia. This study has found that some of the IAQ parameters in the selected classrooms were exceeding the established standards during occupied period in schooldays compared to non-occupied period during weekend. Findings of this study provide the insights for future research including the site selection of school, arrangement of the classrooms and numbers of students per class.

Indoor Air Quality And Its Association With Respiratory Health Among Preschool Children In Urban And Suburban Area

@#Indoor air quality (IAQ) has become a major concern nowadays because of the universality of exposure and its potential negative impact on human health especially on children. This study is intended to explore the association between IAQ and the respiratory health among preschool children in urban and suburban area. A cross-sectional comparative study was carried out among Malay preschool children in urban (N= 60, Puchong) and suburban (N=60, Hulu Langat) areas. An indoor air quality assessment was conducted in 12 preschools and 60 houses which include parameters of PM2.5, PM10, VOCs, mold, bacteria, Gram-negative bacteria and physical parameters. A set of standardized questionnaire was distributed to obtain respondents’ background information, exposure history and respiratory health symptoms. Spirometry test was carried out and the data obtained were analyzed to determine the lung function of the respondents. There was a significant difference between IAQ in urban and suburban preschools for all parameters measured (p<0.05). Most of the pollutants were significantly associated with respiratory health symptoms. There was a significant association between the level of indoor pollutants with the lung function abnormalities among the respondents. Even though this study is the first to take Gram-negative bacteria as an indoor air pollutant, the finding also shows that there is a significant association between exposure of Gram-negative bacteria with lung function impairment and higher reported respiratory symptoms among the respondents. The finding concluded that exposures to indoor air pollutants, especially PM2.5 increases the risk of getting lung function abnormality and respiratory health symptoms among respondents.

Assessment Of Indoor Airborne Microorganisms In A Densely Populated Malaysian Public University

@#Indoor air quality is an essential aspect for occupational health including in a densely populated university. This study aimed to assess the indoor airborne microorganisms via biochemical and molecular approaches in five enclosed workplaces, and their resistance towards six commonly used antibiotics. Cfu/dm2/h for five enclosed workplaces was determined using settle plate technique with 1/1/1 scheme and Gram staining was performed for all pure strains isolated. Two strains with the highest count and with different morphologies were identified using biochemical test as well as 16S rRNA amplification and direct sequencing. Minimum inhibitory concentration for antibiotics was carried out for these two strains. In this study, 27 microbial strains with different morphologies were obtained from all workplaces and 2 strains with the highest count were strain J in café and strain M in library, which were identified as Bacillus cereus and Staphylococcus cohnii, respectively. Both of them were highly susceptible to ampicillin and tetracycline. With resistance up to 0.78 µg/mL; B. cereus was less sensitive to kanamycin and neomycin whereas S. cohnii was less sensitive to streptomycin. In conclusion, antibiotics resistant B. cereus and S. cohnii were two of the microorganisms showing the most abundance in the café and library of a Malaysian public university, respectively. This study may serve as the baseline for the prescriptions of antibiotics to airborne microbial related infections especially to the community in the university who seek for medical treatments; particularly for respiratory and digestive infections which often associated with indoor microenvironment.

Determinación de la calidad bacteriológica del aire en un laboratorio de microbiología en la Universidad Distrital Francisco José de Caldas en Bogotá, Colombia / Bacteriological air quality in a microbiology laboratory at the Distrital Francisco José de Caldas. University in Bogotá, Colombia

Objetivo. Determinar las bacterias del aire de un laboratorio de enseñanza de microbiología de la Universidad Distrital y así establecer la posibilidad de riesgo para la salud a la exponen los usuarios por la presencia de estos microorganismos. Métodos. Se tomaron muestras de aire por la técnica de sedimentación, se realizaron recuentos, y caracterización macroscópica y microscópica de las colonias. Después de aislamientos selectivos se llevó a cabo identificación por BD BBL Crystal. Resultados. Se obtuvo mayor recuento de bacterias Gram positivas que de Gram negativas. Se encontraron bacterias de los géneros Micrococcus, Staphylococcus, Leuconostoc, Bacillus, Corynebacterium, Pseudomonas, Yersinia, Serratia, Shigella, Klebsiella, Citrobacter y Acinetobacter. Los resultados mostraron que las bacterias identificadas no suponen riesgo elevado para la salud de los usuarios sanos, pero que es necesario implementar medidas para disminuir la carga bacteriana y disminuir posibles afecciones generales en la salud de sus ocupantes.

Objective. Determine airborne bacteria in a teaching laboratory of microbiology at the Distrital University and establish the bacteriological quality of air which users are exposed. Methods. Air samples were taken by sedimentation technique. The recovered colonies were counted, macroscopic and microscopic characterized and culture in selective media. The isolates were identifies by BD BBL Crystal. Results. It was found greater counts of gram-positive bacteria compared with Gram negative. It was identified bacteria of genus Micrococcus, Staphylococcus, Leuconostoc, Bacillus, Corynebacterium, Pseudomonas, Yersinia, Serratia, Shigella, Klebsiella, Citrobacter and Acinetobacter. The results showed that the bacteria identified do not present high risk to healthy of users, but it is necessary to implement measures to reduce the bacterial presence. Additionally, in this way decrease possible impact in general health of its occupants.