Indoor and Built Environment

The present paper discusses the systematic study on gamma dose rate, radon exhalation, radium content in soil and sediment and radon concentration in water of Hemavathi River environments. The Gamma dose rate in the air in the study area varied from 98 to 202 nGy h⁻¹ with mean value 145 nGy h⁻¹. The measured dose rate was above the world and Indian average. The mean value of radium activity in soil and sediment was found to be 366.61 and 328.36 mBq kg⁻¹, respectively. The mean value of radon in soil and sediment was found to be 373.90 and 334.90 Bq m⁻³, respectively. The radon concentration of water ranges from 0.20 to 1.60 kBq m⁻³ with an average value of 0.67 kBq m⁻³. The radon in water contributes to dosage in stomach and lungs. The effective doses of radon were calculated and compared with international recommended values. The results show that sediment and water are safe to use for construction and drinking purpose.

There is still a great need for a comprehensive index that could fully describe heat stress and, at the same time, provides a reliable correlation with the physiological responses of the human body. Using artificial neural networks, this study aims to present a new empirical model for predicting heat strain based on body core temperature in workers exposed to hot indoor environments. The study group consisted of 165 male workers working in heat treatment processes of metal industries in the central Iran. A predictive model was developed using eight parameters: age, metabolism rate, body mass index, body surface area, dry-bulb temperature, globe temperature, air velocity and relative humidity. The multilayer feed forward neural networks with different structures were developed using R 3.2.2 statistical software. The results showed that the mean square error of the core temperature predicted by the proposed model was 0.25℃. Based on the Garson algorithm, the dry-bulb and globe temperatures were found to be the most important factors that could affect the human heat strain. The proposed model can be a useful tool for occupational health professionals in analysing heat strain in hot environments.

Computational fluid dynamics (CFD) is an important and effective tool to study the airflow field and contaminant distribution in aircraft cabins. The accuracy of numerical simulation using the CFD approach could be significantly affected by configurations of the inlet boundary conditions, turbulence model, etc. The core of this study was to assess whether conclusions achieved in simulation of airflow on usual surfaces in buildings like in commercial offices could be applicable to aircraft cabins. Comparative studies involving turbulence models or air supply opening models in aircraft cabin environment are still absent in the literature. Therefore, in this study, two turbulence models (the renormalization group (RNG) k-ɛ model and Reynolds-stress model) and three types of air supply opening models (simple open model, basic model and momentum model) were applied to simulate the airflow and contaminant concentration fields in a mockup seven-row cabin section. Our simulation results were compared with the experimental data. Six indexes based on different criteria were used to quantitatively evaluate the agreement between measurements and modelled results given by turbulence models and air supply opening models. The results show that the RNG k-ɛ and RSM turbulence models have similar accuracy in airflow and contaminant fields in the mockup cabin, and the momentum model has the best accuracy among the three air supply opening models for the aircraft cabin environment.

Multi-storey parking structures have potentially high concentrations of benzene (B), toluene (T), ethylbenzene (E) and xylene (X) – known as BTEX which could cause adverse health effects to humans. This study sought to estimate BTEX exposure concentrations among car park workers and to evaluate the extent to which, if at all, changes in urine metabolites are associated with BTEX exposure. Personal BTEX samples were collected from workers. Pre-shift and post-shift urinary metabolites, trans,trans-muconic acid (t,t-MA), hippuric acid (HA) and methyl hippuric acid were assessed using standard procedures. Linear regression models were used to examine associations between BTEX exposure concentrations and changes in urinary metabolites. BTEX concentrations in the car park on Sunday were lower than other days of the week, for instance median concentrations of toluene were 23.3 µg/m³ on Sunday and 48.3 µg/m³ during average weekdays (Tuesday–Friday). Benzene and toluene concentrations adjusted for day of week differences were associated with changes from pre-shift to post-shift in urine t,t-MA and HA, respectively. Car park workers were more likely to be exposed to lower concentrations of BTEX during weekdays compared to weekends. Provision of personal chemical safety protection and rigorous evaluation of its effectiveness in reducing BTEX exposure should be provided to protect workers of car parks.

High strength green composite material has been developed by this project by addition of lime sludge in stabilized class F fly ash with commercial lime and gypsum. The green composite material was shown to have high UCS (unconfined compressive strength) and good California Bearing Ratio (CBR) values to provide sufficient factor of safety as required by the standard code of practice for use in road construction. The good strength is attributed to calcium carbonate in lime sludge, which reacts with pozzolanic products of lime–gypsum stabilized fly ash. X-ray diffraction and scanning electron microscopy have illustrated the interaction/reaction between lime sludge and fly ash and development of additional calcium aluminium oxide carbonate hydrate that has improved the strength of the green composite. The addition of 0.1%, 0.2% and 0.3% (by weight) of short polypropylene (PP) fibre (30 mm size) in the mix has imparted ductility to reduce brittle behaviour. The UCS of 8.1 MPa was achieved with 0.3% fibre in the mix, which is well above the standard requirement. Moreover, durability tests were performed to determine long-term performance. Our overall findings have indicated that the new green composite developed would have good strength, ductility and durability, for construction of flexible pavements. Further research is needed on the long-term field performance for at least one monsoon period before the material can be used with confidence.

The aim of this paper is to survey the decayed historic areas of Isfahan (DHI) in order to determine the relationship between housing satisfaction and quality of life. The related literature on quality of life was reviewed and WHOQOL-BREF model was selected for measuring the quality of life as a whole; also, 17 indicators depicting the housing domain of quality of life were chosen for the purposes of this study. A multi-stage sampling technique was applied to data collection. For data analysis, firstly, the data obtained on 17 indicators of housing domain of quality of life were analysed using factor analysis. The factors extracted are housing quality, housing space, security of tenure and housing affiliation. Secondly, a path diagram was applied to obtain the relation between housing satisfaction sub-domains and the domains of quality of life as a whole. The results indicate that the housing space was the most effective sub-domain of housing on the domains of quality of life as a whole. We also found that in order to improve the housing domain of quality of life in the DHI, due attention should be paid to housing quality factor and to improve quality of life as a whole in these areas, it is also necessary to pay attention to housing space factor.

Historic settlements adapting to local climate and geographical environment contain rich and precious scientific design concepts, which should be investigated extensively. This paper is a study on the sustainable design and planning experiences of Chinese historic settlements. In this study, the thermal environment of Jin-Jiang-Li village with ‘comb-like’ layout in the southern China was simulated to evaluate the interactions between layout, landscape design, and ambient environment. The study has illustrated that the layout as well as the presence of water and vegetation would have an obvious-reducing effect and could play a very important role in improving the microclimate of historic settlements. The findings of our study have an essential practical significance for creating modern sustainable human environments and adapting to the changing modern climate.

Many historical European cities are home to houses of great heritage value. These structures have been able to provide comfort throughout history without the use of artificial conditioning systems. Even though such dwellings were influenced by academic styles, by contradicting vernacular architecture, their adaptation to local climate in order to achieve thermal comfort is commonplace. They were mostly built within compact urban tissues, making use of local materials, workforce and construction technologies. Learning from the past knowledge of these design strategies that are specifically adapted to specific climates can play a significant role in reducing the energy demand of extant buildings. Likewise, this paper thoroughly investigates the remaining urban conglomerate of Cadiz from a scientific approach. An original simulation software, duly tested with on-site measurements, was used to analyse the passive design strategies that were applied effectively. The results of this study indicate that historic neighbourhoods in Cadiz are creatively adapted to their natural conditions. In this sense, the main conclusion is that in mild climates, the combination of a compact urban tissue and climate responsive dwelling design should be sufficient to maintain acceptable indoor comfort levels.

In-situ measurement of radon concentration was carried out in three types of drinking water sources (spring, surface and bore/well). Water samples from all three sources were collected from the city of Abbottabad and its surroundings. Radon concentrations were measured through active technique, using the AB-5 series of portable radiation monitor (Pylon). The mean concentrations (ranges) of radon in the phosphate region were 13.4 ± 2.0 (9.1–23.6), 11.2 ± 1.5 (6.2–20.1) and 7.1 ± 0.9 (4.3–14) kBq m⁻³ in well, spring and surface waters, respectively. Similarly, the mean concentrations (ranges) of radon outside the phosphate region were 7.2 ± 1.0 (3.4–11.5), 5.4 ± 0.7 (2.5–8.9) and 3.1 ± 0.4 (1.7–5.8) kBq m⁻³ in well, spring and surface waters, respectively. The arithmetic mean values of radon concentration in drinking waters in the phosphate and non-phosphate parts or rocks were 10.76 ± 1.5 and 5.10 ± 0.70 kBq m⁻³, respectively. Respective doses of radon taken in by the people via water ingestion and inhalation were calculated as 0.029 ± 0.004 and 0.014 ± 0.002 mSv. The mean values of radon concentrations in drinking water samples collected from Abbottabad phosphate and non-phosphate rocks were below the US EPA Maximum Contamination Level (MCL) of 11.1 kBq m⁻³. The annual mean effective doses of all samples are lower than the reference level of 0.1 mSv a⁻¹ for drinking water as recommended by WHO. Thus, the drinking water of Abbottabad and its surroundings is generally below the recommended levels as regards to radon-related health hazards.

With a view to preventing casualties due to fire outbreaks in residential buildings, we investigated the sound attenuation of audible fire-alarm signals in Korean residential apartment buildings and determine an acoustic condition for enhancing the audibility of such signals. Two sets of field measurements were performed, along with theoretical predictions using sound analysis software. In the first set of measurements, in 17 dwelling units, the standardized alarm sound level requirement of 75 dBA could not be achieved in bedrooms with existing alarm devices. In the second set of measurements, with an additional five dwelling units, both the sound attenuation according to the distance between sound sources and bedrooms and the sound insulation performance of bedroom doors were examined. The sound attenuation levels were increased by 0.72 (R² = 0.7982) and 0.48 (R² = 0.3001) dB m⁻¹ under open- and closed-door conditions, respectively. Further, the bedroom-door sound insulation performance was in the 18- to 23-dB range. Consequently, we have demonstrated that the sound power of a general residential fire alarm must be 98–107.9 dB, depending on the dwelling-unit size and floor-plan type, in order to achieve a bedroom audibility level of 75 dBA.

An extensive survey to measure natural radioactivity in human environment in Jalandhar district of Punjab was undertaken. Results of measurements of indoor radon/thoron and their progeny concentrations are being presented here. Single-entry, pin-hole dosemeters were used for the measurement of radon/thoron concentrations. Deposition-based direct radon/thoron progeny sensors were used for measurement of progeny concentrations. The results have been analysed on the basis of regional characteristics, type of construction and building material used. The radon concentration was found to vary from 6.64 ± 1.72 Bq/m³ to 47.18 ± 4.43 Bq/m³ with geometric mean value of 17.9 ± 2.91 Bq/m³ while the thoron concentration varies from 7.75 ± 2.54 Bq/m³ to 82.68 ± 8.33 Bq/m³ with geometric mean value of 33.54 ± 5.09 Bq/m³. The geometric mean value of equilibrium factor for indoor radon and thoron was found to be 0.43 and 0.02, respectively. The estimated annual inhalation dose varies from 0.22 mSv to 1.76 mSv with geometric mean value of 0.66 mSv. Correlation of indoor radon and air gamma dose rate was also studied.

This paper focuses on the importance of occupant satisfaction with indoor environmental quality in buildings as well as the effect of indoor environmental quality towards occupants’ satisfaction. This research applied post-occupancy evaluation as a method to indicate the building occupants’ needs, their satisfaction and comfort level. The research is based on a case study approach whereby a questionnaire survey was conducted among 25 organizations involved in managing office buildings. A total of 115 questionnaires were returned for evaluation of occupants’ overall satisfaction from aspects of indoor environmental quality in these buildings and to determine the occupants’ satisfaction level within these buildings. The findings revealed that indoor environment factors that could contribute to occupants’ satisfaction consists of lighting, air quality and aesthetic perception. These classifications were made based on the factor analysis done with 22 attributes of the indoor environment. The majority of occupants are satisfied with their health conditions and do not face any serious health problems. However, occupants highlighted that some environmental conditions, health effects, air movement, ventilation and air freshness are important criteria for their satisfaction and comfort. This study provides insights into how occupants perceive their indoor environment and comfort, and identify problems that could arise in buildings.