Indoor and Built Environment

More than three billion people continue to rely on solid fuels as their primary source of domestic energy which is associated with elevated concentrations of indoor air pollutants and increased morbidity and mortality both in adults and children. In Myanmar, solid fuel including coal and biomass (such as dung, crop and charcoal) is the main source of energy used in households. A community-based pilot study was conducted in rural Myanmar with the aim to determine the prevalence of childhood respiratory symptoms in association with the use of biomass for cooking. A total of eighty households were recruited and monitored for exposure to particulate matter with size less than 2.5 μm in aerodynamic diameter (PM_2.5) and carbon monoxide (CO). In addition, mothers were interviewed to understand their cooking habits, some house characteristics and children’s respiratory health. The study found that PM_2.5 and CO were significant contributors for the prevalence of acute respiratory infections and trouble breathing among young children. House characteristics including mosquito coil, associated with children’s respiratory health. The study confirms that domestic environments in developing countries, like Myanmar, continue to have significant health impacts on children.

The underfloor air distribution (UFAD) system has attracted great attention from many researchers and designers due to its advantages of energy conservation and air quality enhancement. In a UFAD system, the conditioned air is directly delivered to the occupied zone, causing thermal stratification from the lower zone to the upper zone. This flow pattern provides better distribution of temperature and airflow than the overhead air conditioning system for its improved ventilation and indoor air quality at the breathing level. This paper focuses on a new and unconventional way of conditioning the interior zones in UFAD buildings by employing large-area grille diffusers in a full-scale experimental room. The influences of swirl diffusers and grille diffusers on the temperature distribution in the UFAD system are compared. The effects of supply air temperature, airflow rates, and number of diffusers on the performance of the UFAD system with grille diffusers are discussed in details. The results show that the large-area grille diffusers can create stratification comparable to the more traditional swirl diffusers and thus provide an alternative way of configuring a UFAD system.

A novel hydrophobic membrane-based dehumidification technology with chilled water is proposed to substitute the traditional dew point method for humidity control in spacecraft, which fulfils the tough tasks of air/water separation and water reuse under low gravity at the same time. A prototype hydrophobic membrane module was designed and fabricated by packing 853 hollow fibres in the shell-and-tube configuration, which could prevent the leakage of the tube-side chilled water to the air side. Theoretical models concerning conjugated heat and mass transfer have been established for the explanation and prediction of the moisture migration across the membranes. Experiments were conducted to validate the theoretical models and the feasibility of water vapour removal under various operating conditions. Although undesirable dewing occurred on the outer membrane surface due to the slow mass transfer relative to heat transfer across the membranes, it was verified by the water increase in graduated cylinder that some water vapour actually transferred through the membrane pores under partial pressure difference. A maximum net dehumidification rate (excluding dewing) of 45 g/h has been achieved by the experiment.

Airborne molecular contaminants strongly affect the cleanroom air quality by severely degrading the image quality of semiconductor devices. This study aims to investigate the removal of N-methyl-2-pyrrolidone (NMP), an organic alkali compound that commonly appeared in cleanroom environment and used for photoresist stripping in integrated circuit fabrication processes, through adsorption by the citric acid (CA)-modified activated carbon chemical filters. Increase in CA concentration showed positive correlation to the quantity of CA coating but had negative influences on specific surface area. Immersion of carbon particles in solutions containing 3 M CA for 3 h yielded the most chemical modification according to the intensity of carbonyl and hydroxyl functional groups attached onto the carbon surface. NMP adsorption breakthrough studies demonstrated that NMP adsorption by virgin activated carbon was ineffective. Increase in the extent of CA modification resulted in greater adsorption capacity of NMP owing to increased quantity of carbonyl functional groups on its surface. Binary-component adsorption tests involving NMP and toluene vapours revealed that the CA-modified filters had little adsorption capability for toluene as compared to virgin filters. On the other hand, NMP was competitively favourable for adsorption on CA-modified filters, even when these filters were pre-saturated with toluene. The results of this research could be of value to cleanroom or building maintenance operators for technical and environmental improvements in future system design.

A combination of quantitative and qualitative approaches was used to evaluate the effectiveness of LEED-certified healthcare settings from the perspectives of both staff and facility managers. This study surveyed 164 staff members in two healthcare settings in a case study to compare LEED and non-LEED-certified healthcare facilities and surveyed 146 staff in six LEED-certified healthcare settings for the main study. Telephone interviews with six facility managers were used to verify the survey results and further examine the facilities' performance and the effectiveness of the LEED strategies. An independent t-test was used to examine the difference between a LEED hospital and a non-LEED hospital in one healthcare system. Building performance was rated higher by staff in the LEED-certified hospital than in the non-LEED hospital. Multivariate analysis of variance (MANOVA) was conducted to compare staff ratings between the silver and gold LEED certification levels and between males and females, as well as to explore the possibility of interaction effects. Compared with the staff in silver-certified facilities, staff members in the gold-certified hospitals gave the buildings significantly higher ratings in most performance variables, including building overall, overall comfort and controllability. Males felt more comfortable than females with temperatures in healthcare facilities.

The construction industry is a flourishing business. Demand for ‘sustainable healthy buildings’ is rapidly increasing with the growing population. As the population increases, problems associated with health impacts of a building would also increase. Addressing the health problems of buildings could require raising of construction cost. In order to maintain a reasonable cost, a construction project might possibly have to compromise health performance and cost, which thus illustrates the major dilemmas being faced in the construction industry. Proper building health management is obligatory to reduce and control health problems and to maintain comfort levels throughout a building’s life cycle. To achieve this, a health performance evaluation model has been proposed to measure the level of health performance throughout a building’s life cycle. However, detail solutions of cost issues are not within scope of this paper. The objective of this paper is to propose a health performance and cost management model to achieve satisfactory health performance level within the project budget. The main significance of this model is to establish a decision-making process for decision-makers to improve and identify problems that could affect the health performance of a building throughout a building’s life cycle, thus allowing stakeholders to resolve shortcomings and to apply advanced solutions for building upgrade.

Lighting is a very important factor in healthcare, with positive effects both on patients' mood and recovery time and on the nursing staff's job satisfaction and reduced stress. Nevertheless, few studies focused specifically on lighting in healthcare buildings. This study investigated the luminous environmental quality through an objective and a subjective approach, reporting results from field activities in four hospitals in Turin and Asti (region of Piedmont, Italy), aimed both at detecting critical conditions of non-compliance with reference to standards and at evaluating visual comfort of patients, visitors and of the nursing staff. From objective measurements, much non-compliance was found. In spite of this, subjective analyses showed that the group of patients and visitors was satisfied with the quality and quantity of lighting within their rooms, while the nursing staff were generally less satisfied. Based on these findings, first considerations for the design of user-centred healthcare buildings are discussed.

Biofilm forming microbial community dwelling on the surface of façade and biodeteriorated 17th century wall paintings of the old Church of the Holy Ascension (Veliki Krčimir, Serbia) was evaluated through microscopic analyses, in order to detect toxigenic agents and assess potential damage caused by biodeteriogens. Initial optical examination of adhesive tape samples revealed complex microbial community flourishing on deteriorated mural surfaces highly enriched with inorganic impurities and organic contaminants of plant and animal origin. A variety of fungal structures, such as melanized hyphae, chlamydospores, fruiting bodies, as well as spores for sexual and asexual reproduction, were predominant in all samples analysed. In addition, among actively growing micromycetes, dematiaceous microcolonial fungi and toxigenic Chaetomium and Cladosporium species were most frequent. Scanning electron microscopy analysis revealed the presence of actinomycetes and highly developed mycelium network within the plaster and paint layers, as well as numerous Cladosporium-like conidial chains and Chaetomium lemon shaped ascospores. Such findings confirm our hypothesis that pulverization of painted layers was most likely due to hyphal penetration and formation of fruiting bodies and other fungal structures. Interestingly, although several green algae were documented on the surface of wall paintings and façade, no cyanobacteria were observed in any of the analysed samples.

The areas pertaining the hydrocarbon and non-hydrocarbon in the Attock district of Pakistan were selected for the measurement of indoor radon concentration. This area was not previously surveyed for such kind of study. CR-39-based NRPB radon dosimeters were utilized for this study. Attock city, Hassan Abdal and Jand belong to the non-hydrocarbon areas, where radon concentration was measured to be 57 ± 11, 58 ± 11 and 56 ± 11 Bq m⁻³, respectively. The hydrocarbon pertaining areas consist of Toot and Meyal villages, the concentration of radon was found to be 48 ± 10 and 37 ± 8 Bq m⁻³, respectively. The cap rock in the geological structures of the hydrocarbon areas may have restricted the migration of underneath radon. The annual effective dose in the studied locations was estimated to be 1.28 ± 0.25 mSv y⁻¹, which is less than the action level recommended by the ICRP. Estimated excess lung cancer risks per million persons per year in the surveyed area show higher values 96, 69, 32–110 and 41–124 as compared to the world average reported by the BEIR-IV (1988), ICRP (1987), US-EPA (1986) and UNSCEAR (1993) models, respectively. Present results could be used as a reference for any future studies in Pakistan for the problems of radon emissions with respect to the types of rocks.

In the present study, an attempt has been made to estimate the actual dose received by the residents due to their exposure to indoor radon, indoor thoron and radon concentration in water of Bathinda district of Punjab considering the different factors like dissolution of gases in blood and contribution of waterborne radon in increasing indoor radon levels following various protocols set up by the United States Environmental Protection Agency. The calculated values have shown a good positive correlation (R² = 0.80) between indoor radon concentration and concentration of radon gas in soil in Bathinda district of Punjab, India. The correlation has been successfully established by using alpha spectrometry technique. Along with this, another linear relationship has also been established between indoor radon concentration and indoor thoron concentration keeping site conditions constant. The ratio of indoor thoron concentration to indoor radon concentration ranges from 0.68 to 1.53 with an average value of 1.10 which indicates that thoron contribution is not negligible in comparison to radon and hence its measurements cannot be neglected. The annual effective dose contributed due to inhalation of radon is 0.86 mSv and due to thoron is 0.96 mSv which is lower than the world average value of annual effective dose reported by the United Nations Scientific Committee on the Effects of Atomic Radiation, 2000.

Indoor radon and soil radioactivity levels were determined for Erzincan province in Turkey. Indoor radon concentrations were determined in 89 dwellings using CR-39 passive Solid State Nuclear Track Detectors (SSNTDs) for four seasons. The mean annual ²²²Rn activity concentration was found to be 119 Bq.m⁻³. In the winter season, indoor radon concentrations showed the highest values while the lowest values were observed in the summer season. A model was used to predict the number of lung cancer incidences due to inhalation of radon. The findings have indicated that radon is responsible for 13% of lung cancer incidences occurring in the Erzincan province. Since indoor radon concentration correlates with ²²⁶Ra content in soil beneath the dwellings, soil samples were collected near the houses where indoor radon measurements were performed in order to seek a correlation. The ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs activity concentration values were 52, 26, 649 and 9 Bq.kg⁻¹, respectively. The annual effective dose due to naturally occurring radionuclides was around 82 µSv.y⁻¹ which is higher than the world average value of 70 µSv.y⁻¹. The results of the present study are expected to be a useful baseline data for future studies.