Poor Indoor Air Research Articles

Thermal performance and indoor air quality in new, medium density houses – Auckland, New Zealand

PurposeNew Zealand’s historical housing stock comprises largely single-storey detached houses, characterised by poor winter comfort with high air infiltration. Challenges with affordability and land use are shifting New Zealand’s housing stock towards double-storey, conjoined medium-density housing (MDH). Reduced external surfaces in this typology should reduce winter heat loss and infiltration, improving winter comfort and health. New concerns arise, however, regarding summertime overheating and poor indoor air quality.Design/methodology/approachA field study was undertaken where temperature, humidity, airtightness, particulate matter (PM) and total volatile organic compounds (TVOC) were measured in two unoccupied, newly built double-storey, conjoined houses, for several weeks over summer.FindingsThe reduced surface area of this typology did not reduce infiltration and demonstrated significant periods of overheating. Internal PM concentrations generally exceeded outdoor concentrations but did not exceed annual average outdoor PM10 guidelines of 20 µg m-3. Infiltration factors (Finf) were closer to more traditional houses. TVOC readings varied widely, but frequently exceeded international guidelines.Research limitations/implicationsThe small sample limits the applications of conclusions more widely. Recommendations to investigate a wider sample in different locations with more detailed VOC analysis over all seasons are made.Practical implicationsImprovements to internal environments cannot be guaranteed by housing typology changes alone and must still involve thoughtful environmental design.Social implicationsHousing typology changes may not improve internal living environments.Originality/valueA move to the new MDH typology may not achieve expectations of airtightness and thermal improvement. New challenges arise from significant overheating and high TVOC levels, which may lead to new negative health effects.

Time-Resolved Characterization of Indoor Air Quality due to Human Activity and Likely Outdoor Sources during Early Evening Secondary School Wrestling Matches

Despite positive health outcomes associated with physical activity as well as individual and team sports, poor indoor air and environmental quality can adversely affect human health, performance, and comfort. We conducted a 14-month field case study incorporating two winter sports regular seasons (12/2017–2/2019) including analyses of particulate matter (PMx) in air and in dust, carbon dioxide (CO2), temperature, and relative humidity (RH%) during secondary or high school wrestling activities in southern New Jersey, USA. After planning and piloting methods during the first winter sports regular season (12/2017–2/2018), during the second winter sports regular season (1–2/2019), we conducted a purposeful simultaneous real-time sampling midgymnasium adjacent to the wrestling mats. Gymnasium occupancy ranged 100–500 people. Data collected included inhalable PM10 resuspended from floor mats, fine respirable PM2.5, and indoor CO2, temperature, and RH%. Short-term real-time elevated PM10 levels were directly compared with simultaneously documented wrestling match bouts, e.g., student-athlete takedowns and pins. PM10 and PM2.5 levels were compared with other known documented activities indoors (e.g., snack bar) and sources outdoors (e.g., adjacent parking lot and major freeway). To understand CO2, temperature, and RH% data, we characterized the HS gym mechanical ventilation system—no doors or windows outdoors—and recorded occupancy during match hours. Indoor CO2 levels ranged ∼700–1000 ppm during match #1 on 1/23/2019 but ranged from ∼900 to 1900 ppm during match #2 on 1/30/2019, with >1000 ppm for the majority of the time (and throughout the entire varsity match when occupancy was at maximum). Future research should further characterize PM10 constituents in mat dust and indoor air with larger samples of schools and matches.

Models for assessment of volatile organic compound diffusivities in leather or leather imitates by mercury intrusion porosimetry test

Recent studies have been conducted on the characteristics of volatile organic compound emissions; most of them are focused on wood-based building materials, scarcely mentioned about leather or leather imitates. The volatile organic compound emissions of these products may cause poor indoor (vehicle cabins included) air quality. This article takes formaldehyde as an example to study its diffusion in leather. The porous structure of leather was characterized by carrying out mercury intrusion porosimetry test. The formaldehyde diffusivities in leather was assessed by Blondeau et al.’s, Ataka et al.’s, and Xiong et al.’s models which represent parallel, equivalent, and series interconnection of pores, respectively, and validated through independent liquid inner tube diffusion film emission experiments. The results demonstrated that the fractal dimension of leather is 2.19, which indicated it is a porous medium with self-similar pore structure. Most of the pores in leather were macro pores with average diameter 16.56 μm which contributed to 95.9% of whole porosity and the meso pore with average diameter 0.60 μm which contributed to 4.1%. As far as the liquid inner tube diffusion film emission experiment shows, the Xiong model agrees much better with the experimental results than the other two. The two kinds of pores were considered to be serially connected. It is useful for predicting volatile organic compounds diffusion coefficient in a short time and can be applied to the design and development of low volatile organic compound emission leather or leather imitates within further research.

Facility performance evaluation to develop heating, ventilation, and air-conditioning system design and operation strategies for an office building in Mongolia

A facility performance evaluation (FPE) study was applied to an occupied office building in Mongolia that would be replaced by a new building. The purpose was to identify indoor environmental quality (IEQ) problems and possible solutions in the current building to inform the design and operation of the heating, ventilation, and air-conditioning (HVAC) system for the new building. The results show that the IEQ of the current building was poor due to high temperature, very low humidity and high CO2 concentration, and that the poor thermal uniformity and indoor air quality had caused the occupants’ discomfort. Opening windows by the occupants in winter was one of the problems that affected the thermal comfort and the energy efficiency of the building. Based on the findings of the FPE, this study recommended the design and operation strategies of the HVAC system for the new building to improve its IEQ.

Mutagenicity and Pollutant Emission Factors of Solid-Fuel Cookstoves: Comparison with Other Combustion Sources.

Background:Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects.Objective:We evaluated two categories of solid-fuel cookstoves for eight pollutant and four mutagenicity emission factors, correlated the mutagenicity emission factors, and compared them to those of other combustion emissions.Methods:We burned red oak in a 3-stone fire (TSF), a natural-draft stove (NDS), and a forced-draft stove (FDS), and we combusted propane as a liquified petroleum gas control fuel. We determined emission factors based on useful energy (megajoules delivered, MJd) for carbon monoxide, nitrogen oxides (NOx), black carbon, methane, total hydrocarbons, 32 polycyclic aromatic hydrocarbons, PM2.5, levoglucosan (a wood-smoke marker), and mutagenicity in Salmonella.Results:With the exception of NOx, the emission factors per MJd were highly correlated (r ≥ 0.97); the correlation for NOx with the other emission factors was 0.58–0.76. Excluding NOx, the NDS and FDS reduced the emission factors an average of 68 and 92%, respectively, relative to the TSF. Nevertheless, the mutagenicity emission factor based on fuel energy used (MJthermal) for the most efficient stove (FDS) was between those of a large diesel bus engine and a small diesel generator.Conclusions:Both mutagenicity and pollutant emission factors may be informative for characterizing cookstove performance. However, mutagenicity emission factors may be especially useful for characterizing potential health effects and should be evaluated in relation to health outcomes in future research. An FDS operated as intended by the manufacturer is safer than a TSF, but without adequate ventilation, it will still result in poor indoor air quality.Citation:Mutlu E, Warren SH, Ebersviller SM, Kooter IM, Schmid JE, Dye JA, Linak WP, Gilmour MI, Jetter JJ, Higuchi M, DeMarini DM. 2016. Mutagenicity and pollutant emission factors of solid-fuel cookstoves: comparison with other combustion sources. Environ Health Perspect 124:974–982; http://dx.doi.org/10.1289/ehp.1509852

INDOOR MICROBIAL CONTAMINATION THROUGH WATER MIST AEROSOL AT PUBLIC RESTAURANTS

In Malaysia and many other Asian countries, countless number of restaurants are made of open or semi-open air buildings. These restaurants are commonly located beside roads, factories, and construction sites. The foods are often exposed to the air, increasing their tendency to be contaminated due to poor indoor and outdoor air quality. There are very few studies characterising and comparing the levels of indoor air pollutants in restaurants. Other than that, scarce data are available on dining establishments especially in the presence and absence of water mist application system. Due to these reasons, no best practices or guidelines can be developed. Hence, this present study aimed (1) to assess and compare the physical indoor air quality (IAQ) characteristics and airborne pollutants between different types of restaurant settings; (2) to identify microbes isolated in the presence and absence of water mist system; (3) to analyse bacterial counting within and between the different restaurant settings; and (4) to determine the relationship between physical IAQ characteristics and airborne microbial contaminants. Instruments known as Dustmate and VelociCalc® Multi-Function Ventilation Meter 9565 were used to measure the physical IAQ characteristics and airborne particulate matters. On the other hand, Surface Air System Indoor Air Quality (SAS IAQ) was use to seize the microbial contaminants. All the data obtained were compared with the standard reference known as the Industrial Code of Practice on Indoor Air Quality (2010) constructed by the Department of Occupational Safety and Health (DOSH). This study later indicated that the level of indoor PM10 concentrations was influenced by changes of physical IAQ parameters at the two restaurants investigated. As the PM10 increased, the colony forming unit (CFU) counting also increased. Although microbial contaminations were found during both periods of exposure (i.e., in the presence and absence of water mist) at both restaurants, significant relationship between the parameters measured cannot be determined. The bacterial species obtained during the presence and absence of water mist application system for both of the restaurants were also identified. Gemella morbillorum was found as the most dominant species, followed by other species such as Aerococcus viridans, Globicatella sanguinis, Leuconostoc spp., and Proteus penneri.

Sustainable workplaces and building user comfort and satisfaction

PurposeThis paper aims to examine the role of sustainable buildings in providing healthy workplaces in physical and perceptual terms.Design/methodology/approachThe paper takes the form of a literature review, considering the history of sustainable development in the built environment and its rationale, then widening the scope to consider sustainable, healthy and productive workplaces.FindingsSustainable construction has focused on environmental sustainability but this may have contributed to improved health, satisfaction and wellbeing amongst building users. Sick building syndrome and poor indoor air are contributory factors to ill health and reduced productivity but this paper suggests that sustainable building practices will reduce these effects, improving the quality of buildings for their occupants.Practical implicationsThis paper argues that building performance measures need to take account of people factors such as employee perceptions and also that the design of workplaces should be regarded as a strategy for productivity enhancement. Management issues should be considered in the design of workplaces. The paper concludes that further research is required into the role of sustainable construction in providing healthy buildings.Originality/valueThe paper makes practical suggestions for corporate real estate and facilities management teams as well as those involved in the design of the buildings. Additionally, it opens suggested avenues for further academic research.

Sick Buildings or Not: Indoor Air Quality and Health Problems in Schools

Poor indoor air in schools has become a wide-spread problem with serious effects on occupant health. Resultant costs can be considerable at both local and national government levels. These include absenteeism and rehabilitation as well as building alterations and even demolition and rebuilding. This project aims to show factors contributing to health problems in Swedish schools. It includes a literature survey and particle measurements taken during various activities. Due to the fact that today there is no standard for indoor air quality (IAQ) in schools, in this project we used the outdoor air surrounding the building as an indicator. Results showed that indoor school environments had high airborne pollution levels, to a degree that probably causes health problems for many people. Regarding IAQ, this project shows the importance of taking into consideration choices in activities and furnishing of the building.

Fine particle number and mass concentration measurements in urban Indian households

Fine particle number concentration ( D p>10 nm, cm −3), mass concentrations (approximation of PM 2.5, μg m −3) and indoor/outdoor number concentration ratio (I/O) measurements have been conducted for the first time in 11 urban households in India, 2002. The results indicate remarkable high indoor number and mass concentrations and I/O number concentration ratios caused by cooking. Besides cooking stoves that used liquefied petroleum gas (LPG) or kerosene as the main fuel, high indoor concentrations can be explained by poor ventilation systems. Particle number concentrations of more than 300,000 cm −3 and mass concentrations of more than 1000 μg m −3 were detected in some cases. When the number and mass concentrations during cooking times were statistically compared, a correlation coefficient r>0.50 was observed in 63% of the households. Some households used other fuels like wood and dung cakes along with the main fuel, but also other living activities influenced the concentrations. In some areas, outdoor combustion processes had a negative impact on indoor air quality. The maximum concentrations observed in most cases were due to indoor combustion sources. Reduction of exposure risk and health effects caused by poor indoor air in urban Indian households is possible by improving indoor ventilation and reducing penetration of outdoor particles.