3,111 research outputs found

    Health and economic benefits of building ventilation interventions for reducing indoor PM2.5 exposure from both indoor and outdoor origins in urban Beijing, China

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    China is confronted with serious PM2.5 pollution, especially in the capital city of Beijing. Exposure to PM2.5 could lead to various negative health impacts including premature mortality. As people spend most of their time indoors, the indoor exposure to PM2.5 from both indoor and outdoor origins constitutes the majority of personal exposure to PM2.5 pollution. Different building interventions have been introduced to mitigate indoor PM2.5 exposure, but always at the cost of energy expenditure. In this study, the health and economic benefits of different ventilation intervention strategies for reducing indoor PM2.5 exposure are modelled using a representative urban residence in Beijing, with consideration of different indoor PM2.5 emission strengths and outdoor pollution. Our modelling results show that the increase of envelope air-tightness can achieve significant economic benefits when indoor PM2.5 emissions are absent; however, if an indoor PM2.5 source is present, the benefits only increase slightly in mechanically ventilated buildings, but may show negative benefit without mechanical ventilation. Installing mechanical ventilation in Beijing can achieve annual economic benefits ranging from 200yuan/capita to 800yuan/capita if indoor PM2.5 sources exist. If there is no indoor emission, the annual benefits above 200yuan/capita can be achieved only when the PM2.5 filtration efficiency is no less than 90% and the envelope air-tightness is above Chinese National Standard Level 7. Introducing mechanical ventilation with low PM2.5 filtration efficiency to current residences in urban Beijing will increase the indoor PM2.5 exposure and result in excess costs to the resident

    The effect of short-term changes in air pollution on respiratory and cardiovascular morbidity in Nicosia, Cyprus.

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    Presented at the 6th International Conference on Urban Air Quality, Limassol, March, 2007. Short-paper was submitted for peer-review and appears in proceedings of the conference.This study investigates the effect of daily changes in levels of PM10 on the daily volume of respiratory and cardiovascular admissions in Nicosia, Cyprus during 1995-2004. After controlling for long- (year and month) and short-term (day of the week) patterns as well as the effect of weather in Generalized Additive Poisson models, some positive associations were observed with all-cause and cause-specific admissions. Risk of hospitalization increased stepwise across quartiles of days with increasing levels of PM10 by 1.3% (-0.3, 2.8), 4.9% (3.3, 6.6), 5.6% (3.9, 7.3) as compared to days with the lowest concentrations. For every 10μg/m3 increase in daily average PM10 concentration, there was a 1.2% (-0.1%, 2.4%) increase in cardiovascular admissions. With respects to respiratory admissions, an effect was observed only in the warm season with a 1.8% (-0.22, 3.85) increase in admissions per 10μg/m3 increase in PM10. The effect on respiratory admissions seemed to be much stronger in women and, surprisingly, restricted to people of adult age

    Particles in the Indoor Environment

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    TVOCs and PM 2.5 in Naturally Ventilated Homes: Three Case Studies in a Mild Climate

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    In southern Europe, the present stock of social housing is ventilated naturally, with practice varying in the di erent seasons of the year. In winter, windows are kept closed most of the day with the exception of short periods for ventilation, whereas the rest of the year the windows are almost permanently open. In cold weather, air changes depend primarily on the air infiltrating across the envelope and when the temperature is warm, on the air flowing in through open windows. CO2, PM2.5, and TVOC concentration patterns were gathered over a year’s time in three social housing developments in southern Europe with di erent airtightness conditions and analyzed to determine possible relationships between environmental parameters and occupants’ use profiles. Correlations were found between TVOC and CO2 concentrations, for human activity was identified as the primary source of indoor contaminants: peak TVOC concentrations were related to specific household activities such as cooking or leisure. Indoor and outdoor PM2.5 concentrations were likewise observed to be correlated, although not linearly due to the presence of indoor sources. Ventilation as presently practiced in winter appears to be insufficient to dilute indoor contaminants in all three buildings, nor does summertime behavior guarantee air quality

    Xenobiotic particle emission formation in fixed-bed domestic coal combustion

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    Abstract : Combustion of solid fuels have been reportedly associated with several cases of cardiovascular, respiratory and neurological diseases. Furthermore, it is suggested that premature deaths and morbidity cases may be prevented by the use of clean energy technologies than coal and wood burning. In South Africa, despite 87% of households being connected to the grid, over 50% and 75% of households in urban and rural areas continue to depend on wood and coal for major household activities respectively. In 2004 the Department of Minerals and Energy advocated for the use of toplit updraft method (TLUD) as an interim clean coal burning technology. The initiative has been associated with the reduction of visible smoke/particulate matter (~80%) and coal consumption. However, studies suggest that there might be other emissions other than PM at household or regional level from such technologies which may be detrimental to health and environmental performances, which requires further investigations. This present study has investigated the emissions of xenobiotic pollutants emitted from small-scale combustion technology currently in use and advocated to be used in South African low-income settlements. The study focused on emission factors from small-scale coal combustion technologies, influence of coal properties on emissions, particle size distribution at different combustion phases, the physicochemical properties of emitted particles, risk assessment of BTEX emissions, toxicity and cellular uptake of particulate matter from coal combustion. All experiments were carried out in a laboratory environment in order to minimize contribution of other environmental contaminants, which were not intended for the scope of the project. The emission factors of CO2, CO, and NOx ranged from 98–102 g MJ-1, 4.1–6.4 g MJ-1, and 75–195 mg MJ-1, respectively. Particulate matter (PM2.5 and PM10) emissions were in the range 1.3–3.3 g MJ- 1 for the BLUD method, and 0.2–0.7 g MJ-1 for the TLUD method, for both field and lab-designed stoves. When employing the TLUD method, emission factors of PM2.5/PM10 reduced by up to 80% compared to the business as usual BLUD method. The fuel moisture content (from 2.4 wt.% to 8.6 wt.%) led to an 18 and 30% decrease in fire-power when using the TLUD and BLUD methods, respectively. Measured carbon monoxide (CO) emission factors (EF) increased with an increase in moisture content, while carbon dioxide (CO2) EF remained unchanged. The use of A-grade coal resulted in 49% increase in PM emissions compared with D-grade coal at high ventilation rates. Particles from the top-lit updraft (TLUD) showed an ultrafine geometric mean diameter centred at approximately 109 ± 18.4 nm for the ignition phase, 54.9 ± 5.9 nm for the pyrolysis/flaming phase, and 31.1 ± 5.1 nm for the coking phase. In studying the physical properties of smoke particles from coal burning three types of shapes were classified, viz., spherical organic particles with similar characteristics to tarballs (ignition), soot particles (flaming), and mineral particles (char-burning). Elemental composition was determined using ICP-MS and it was found that 55%, 28% and 17% of the selected elements (Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu 63, Zn) were emitted during the char burning, flaming and ignition phase, respectively. However, during ignition most emitted element were K and Si, which may be used as markers for the simultaneous combustion of wood and coal. When using near-field breathing zone concentration of BTEX in a simulated exposure scenario applicable for a typical coal burning South African household, the cancer risk for adult males iii iii and females, was found to be 1.1 -1.2 and 110-120 folds higher than the US EPA designated risk severity indicator [1E-6], respectively. All four TEX compounds recorded the Hazard Quotient [HQ] of less than 1, indicating a low risk of developing related non-carcinogenic health effects. Lastly, smoke particles emitted from the TLUD ignition from a high-ventilated stove were used to determine the cytotoxicity and cellular uptake. Particles from three combustion phases showed mild toxicity on the bronchial epithelial cells at highest concentration of 150 μg/ml while lower concentrations (20 μg/ml, 60 μg/ml 100 μg/ml) did not indicate significant toxicity on the cells. The results of this study have shown that the emissions of health and environment damaging may be significantly reduced by the correct selection of stove to fuel combinations. The PM emissions are directly proportional to the stove type, fuel properties and ignition method. Stoves with higher ventilation rate ignited using fuel with low moisture content and lit with the TLUD ignition method, produces optimum performance on the reduction of PM2.5 and PM10. However, the use of fire ignition method and coal with different moisture content did not show a convincing reduction on the gaseous emissions. Therefore, it remains important when promoting clean coal burning technologies to take cognisance on non-conclusive information of emission performance, particularly on gaseous emissions. It was further, established that particles emitted from domestic coal burning are of small diameter with an average mean of less than 100 nm. This is concerning due to the longer residence time of small particles on air spaces and higher deposition rate in the lower respiratory track of the exposed individual. The emitted particles low to medium temperature produced organic enriched spherical particle with similar characteristics to tarballs. The emissions of BTEX remains a worrying subject given the high probability of cancer under a defined exposure scenario defined under this project. Therefore, it remains important not to rule out the potential harm associated with gaseous emissions when promoting the technology (use of TLUD ignition method).Ph.D. (Energy Studies

    Workplace personal exposure to respirable PM fraction: a study in sixteen indoor environments

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    AbstractThe present paper focuses on respirable particulate matter (RPM) measurements conducted at the breathing zone of adult volunteers in sixteen different working environments: two offices, a house, a chemical laboratory, a non–smoking shop, a pharmacy store, a car garage, a hairdresser's store, a photocopy store, a taxi, a gym, a mall, a restaurant, a bar, a kiosk and a school. The sixteen different cases were categorized according to the location, the type of the activities taking place indoors, the number of occupants, the proximity to heavy traffic roads, the ventilation pattern etc. According to the results, the maximum particle concentration (in average 285μg m−3) was recorded at the hairdresser store while the minimum concentration was measured in the cases of the housewife and the employee in the non–smoking shop (in average 30μg m−3). The results indicated smoking as a factor which strongly influences the exposure levels of both smokers and passive smokers. Furthermore, it was found that the building ventilation pattern comprises an important factor influencing the exposure levels especially in cases of buildings with great number of visitors (resuspension) and smoking

    The Connection between Indoor Air Quality and Mental Health Outcomes

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    Mental health among United States citizens, military members, and veterans warrant research into factors not fully considered for their effects on mental health. The built environment is increasingly recognized as a potential influence on the mental health of occupants. Specifically, indoor air quality is theorized to contribute to mental illness. Through the development of a literature review, specific air pollutants common in the built environment were identified, and the mechanisms behind their effect on mental health were explored. A model framework is outlined, estimating the number of cases of major depressive disorder attributable to indoor exposure to particulate matter. The model also performs a benefit-cost analysis of different residential filters, outlining which filter is the most financially efficient for the purposes of reducing major depressive disorder outcomes. Finally, a discussion of particulate matter is elaborated, outlining ways in which engineers and architects, as well as homeowners, can decrease particulate matter concentrations indoors

    Fine and ultrafine particulate: sampling, analysis and metal characterization for a risk assessment on human health.

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    Information about the size-distribution of airborne particulate matter (PM) and PM-bound toxic metals is a key knowledge in terms of health concern. The global aim of the project was to characterize the mass concentration, size-distribution and metal composition in different PM2.5 size ranges. The experimental design involved the collection of size-segregated particles at an outdoor urban background site in Como during a long-term monitoring campaign by means of a multistage low pressure impactor. The highest PM concentration levels were found during the heating period because of a joint influence of meteorological factors and variations in type and number of emission sources. In particular, the greatest and significant increase effect was registered for particles between 0.15 and 1.60 \u3bcm. For chemical analysis purposes, a novel and reliable Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) measurement protocol was properly developed and optimized, providing precise and accurate results. The proposed LA-ICP-MS method was then applied for the analysis of selected trace metals (Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb) on the extended set of size-segregated PM samples. Obtained findings revealed different and characteristic metal size-distributions in the fine, submicrometer and ultrafine fractions. The studied elements were variously enriched in the particulate sizes, suggesting that local emission sources may exist for these chemical species. Moreover, from a health and sanitary perspective, the estimated hazard quotient and index values suggested no non-carcinogenic health risks via the inhalation exposure route. Also the carcinogenic risks of Cr and Ni were within the acceptability range
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