Enhance Air Quality Research Articles

School building energy performance and classroom air environment implemented with the heat recovery heat pump and displacement ventilation system

Recent built low energy school buildings have adopted a novel heat recovery heat pump and classroom ventilation system. School building energy conservation performance and classroom air quality enhancement will be simultaneously investigated in the present work. Heat recovery efficiency of the heat recovery facility and energy conservation ratio of the heat pump unit were analytically modeled, taking the classroom ventilation network into account. Following that, classroom displacement ventilation and its thermal stratification have been investigated concerning the effects of delivering ventilation flow rate and supplying air temperature. Representative thermal comfort parameters, percentage dissatisfied, temperature difference between ankle and head, and draft dissatisfaction have been evaluated. Indoor air quality indicated by the CO2 concentration was also investigated in terms of different levels of ventilation flow rate. Classroom energy demands for ventilation and winter heating have been shown to decrease with the promotion of heat recovery efficiency of the ventilation facility, and the energy conservation ratio of the heat pump increases with temperature of supplying fresh air. Detailed correlations of heat recovery ventilation and heat pump energy conservation have been presented. This research illuminated that enhancement of classroom air quality and reduction of school building energy consumption could be simultaneously achieved with the appropriate operation of heat recovery heat pump and ventilation system.

Analysis and construction of stress relief model for healthy indoor environments

Currently, the average person spends 80–90 % of their workday in an airtight indoor environment. Under such conditions, the presence of organic chemical pollutants in the air can compromise the health of workers and undermine work efficiency. Many researchers have demonstrated that plants can be used to purify the air and relive stress, essential oils can promote positive emotions and eliminate negative thoughts, and music can relieve stress by calming nerves and relaxing muscles. All of these are positively related to the release of stress and the promotion of health. This study employed three factors to construct environment-related dimensions with an influence on stress relief. We employed analytic network process to identify the environmental factors that are essential to stress relief, in conjunction with Taguchi method to determine the best combination of parameters. A model based on statistical analysis was used to verify the different benefits resulting from these changes. The proposed system provides an effective means to enhance air quality in the promotion of a comfortable, clean, and healthy environment. Our findings provide a valuable reference for the implementation of environment improvements in medical facilities, retirement homes, and office spaces.

Experimental evaluation of VOC removal efficiency of a coconut shell activated carbon filter for indoor air quality enhancement

The present study evaluated the performance of a commercially available activated carbon filter for VOC removal from air through the analysis of real samples. The filter was tested for VOC reduction efficiencies in a PVC portable inflatable bubble provided with an air purifier system called Airbox II Phase by Zonair3d, as described hereinafter. The filter was placed in the Airbox II Phase of the bubble, between a pre-filter and a particulate HEPA H14 filter. Simultaneous duplicate samples were taken from the input air duct before the driving system and from the bubble. VOC were dynamically sampled during 2-h control periods by connecting custom packed glass multi-sorbent cartridge tubes (Carbotrap, Carbopack X and Carboxen 569) to air pump samplers. A validated analytical method based on TD-GC/MS was used to quantify a wide variety of VOC families (alkanes, aromatic hydrocarbons, alcohols, ketones, halocarbons, aldehydes, esters, terpenes, ethers, glycols and nitrogenated compounds). VOC family removal efficiencies ranged from 51 ± 19% to 78 ± 22% with input indoor air, and from 42 ± 16% to 91 ± 18% with input outdoor air. No significant differences in reduction efficiencies (t-test; p < 0.05) were observed between using indoor or outdoor air. Several aldehydes were desorbed from the filter at low concentrations (0.09–21.19 μg m−3) when outdoor air was used as input air. Ozone removal efficiency was assessed by a continuous monitoring system. A 100% yield was obtained in all cases where ozone was present.

Air quality evaluation on an urban scale based on MODIS satellite images

Earth-observing satellites have provided satellite image datasets for urban-scale air quality monitoring. Aerosol optical thickness (AOT) at 1km resolution is retrieved from MODIS on Terra Satellite by using the improved algorithm. The 1km AOT data are validated by using AOT measurements from two AERONET stations and the 10km AOT products from MOD04_L2 in the period of October 2004. Then the validated 1km AOT data are compared with ground-based PM2.5 mass concentration in Beijing. Four empirical models which are used to investigate the relationship between AOT data and PM2.5 mass concentration are obtained by regression analysis and their correlations are R2=0.818, R2=0.750, R2=0.699 and R2=0.629 respectively. In order to verify the models, we use these models to retrieve PM2.5 concentration from MODIS AOT on the 11th of October 2012 and then compare it with the PM2.5 concentration from the ground measurements in that day. 50%, 46.4%, 46.4% and 39.3% of the stations are within the expected errors respectively by the four models. Preliminary analysis of these four models indicates that the quadratic model has significant potential to enhance air quality monitoring on an urban scale. Although the limited daily MODIS AOT data, variability of terrain, weather conditions, and many other factors can limit the ability of predicting PM2.5 concentration, the models provide a cost-effective approach for obtaining the distribution of PM2.5 information from satellite image, which complement the defects of the limited ground-based monitoring station measurements.

Air quality enhancement zones in Taiwan: A carbon reduction benefit assessment

Air pollution control is an important aspect of environmental protection in Taiwan. In 1995, Taiwan's government began, via afforestation, to establish air quality enhancement zones (AQEZs) in order to promote multiple environmental benefits, including improved air quality, increased carbon sequestration, and enhanced environmental quality of life. In 2010, there were over 504 such zones. In addition to providing urban forests and green spaces, tree growth in AQEZs can sequester atmospheric carbon dioxide and, by shading and evapotranspiration, reduce energy demand and increase soil storage of organic carbon. In addition, afforestation can offset the carbon footprint of the world's population and is one of the best approaches to implementing carbon neutrality. The purpose of this study was to analyze the carbon reduction benefits of afforested AQEZs. Investigations of 48 AQEZs showed (1) a high diversity of trees planted (168 species), (2) an average density of trees of 1142/ha, (3) a forest timber volume of 23.92m3/ha, lower than in standard plantations, (4) a carbon storage capacity of 9.25tons/ha, and (5) average annual carbon sequestration of 1.34ton-C/ha/yr. Carbon sequestration by AQEZs in Taiwan, although not remarkably high, is nevertheless, along with other ecosystem services provided by AQEZs, a significant and direct benefit to the urban public. This study provides a reliable basis of measureable results with which decision makers can evaluate benefits of urban forest carbon sequestration.

Hotel Indoor Air Quality Enhancement: Research Agenda

The article reports on the penetration of polluted outdoor air into hotels and the subsequent deterioration of indoor air quality (IAQ). Little attention has been paid to the severity of this problem. Thus, the study specifically aims to assess the determinants to enhance IAQ in hotels and suggest a future research direction relating to IAQ enhancement. Evidence from recent air pollution studies in hotels located in the Pearl River Delta is synthesized and further augmented by studies in other cities in the territories. Six determinants that motivate the enhancement of hotel IAQ have been identified, including poorer IAQ in new hotels, worsening atmospheric air quality in cities, environmental tobacco smoke, increasing number of automobiles, property development, and airlines. A research agenda was drawn up with a focus on soliciting feedback from stakeholders about their attitudes on available and future mitigating measures, provision of hotels as pilot test sites, as well as decision-making criteria about IAQ enhancement program. In addition, the study calls for more resources for conducting IAQ-related research and advocates extending the research frontier into the inclusion of IAQ in hotel rating schemes.

Regulation of Shale Gas Development, Including Hydraulic Fracturing

This paper provides one of the first detailed surveys of current oil and gas and hydraulic fracturing (also called fracing, fracking, or hydrofracking) regulation. It identifies and compares the environmental laws and regulations that apply to most stages of the oil or gas development process in shales and tight sands, from conducting seismic testing to constructing a well pad, drilling, withdrawing water, completing a hydraulic fracture treatment, and storing and disposing of waste. It briefly describes municipal ordinances and federal regulations, including recently-announced EPA regulatory efforts, but focuses primarily on the states, comparing regulations in sixteen states. The paper's comparison tables show that state regulations in some areas vary substantially, and the paper attempts to connect the potential risks of oil and gas development from shales and tight sands -- which are addressed in another Energy Institute paper by Professor Ian Duncan -- to the regulation. The paper concludes that states should modify certain regulations to address these risks. Some states do not require specific types of blowout prevention, for example, offering only a narrative standard, yet well blowouts are an important concern at the drilling and fracturing stage. States also should update their casing and cementing regulations to protect well integrity during drilling and fracturing and ensure long-term well integrity, and they should require the testing of water around proposed wells before site construction begins. Ideally, states also would consider implementing a presumption of oil and gas operator liability for water well contamination, as Pennsylvania and West Virginia have done. For risks at the well surface, states should update spill prevention requirements at well sites and consider whether federal Department of Transportation regulations addressing the movement of fracturing chemicals adequately protect against spills. States also must explore better options for disposing of large quantities of new wastes and regulating the withdrawal of large volumes of water for fracturing to prevent adverse impacts to streams and overuse of underground sources of water. Further, states and the federal government must enhance air quality monitoring around sites and consider additional controls. Finally, the collection of more and better data, including information from baseline and post-production water testing, is essential. With states at the regulatory helm, comparison of public law strategies to address development risks can produce fruitful cross-jurisdictional lessons. The Energy Institute at the University of Texas funded the research for this paper.

Comparing HEPA versus HEPA-VOC filtration system: influence on embryo quality and clinical outcomes of in vitro fertilization

OBJECTIVE: Incubator filtration units with activated carbon eliminate volatile organic compounds (VOC) and enhance air quality. We compared the effects of filtration on CO2 incubator between a traditional high efficiency particle air (HEPA) and HEPA-VOC on subsequent embryo (EB) quality and clinical outcomes of IVF. DESIGN: Prospective randomized study. MATERIALS AND METHODS: Total of 162 patients treated by ICSI, from March 2008 to March 2009. The rates of Fertilization (2PN), EB grade A classification, (7 - 8 cells, equal size blastomeres and fragmentation < 5% at 68 – 72 hours), blastocyst formation, EB transfer, EB transfer grade A classification, clinical pregnancy, abortion and implantation were the outcomes measures compared on the HEPA and HEPA-VOC groups. Chi-square test was used for statistical analysis at p < 0.05. RESULTS: Groups were statistically similar in basal characteristics. Patients with the embryos cultured in incubators with HEPA-VOC filters had more grade A embryos on third culture day (p = 0.0008). Basal characteristics and clinical outcomes are shown on.Table ICharacteristic patients and clinical outcomes.HEPAHEPA-VOCp valueNo. of cycles7686p valueAge35.15 ± 6.6434.67 ± 5.900.79Oocytes retrieval11.71 ± 10.3311.11 ± 8.070.89Oocytes MII/ICSI9.68 ± 7.978.61 ± 6.420.082PN oocytes6.12 ± 2.895.47 ± 3.170.15EB grade A10.2 ± 0.4511.4 ± 3.530.0008Blastocyst4.8 ± 1.645.6 ± 1.710.93EB transfer2.96 ± 12.93 ± 0.870.20EB transfer A classification1.89 ± 0.731.82 ± 0.640.08Clinical pregnancy rate (%)36/76 (47.36%)39/86 (44.82%)0.92Abortions6/36 (16.66%)3/39 (7.69%)0.40Implantation36/163 (22.08%)46/241 (19.08%)0.54Values are expressed as mean ± standard derivation. Open table in a new tab Values are expressed as mean ± standard derivation. CONCLUSIONS: Rate of A embryos on day 3 was higher on culture with HEPA-VOC filters. Clinical outcomes did not reach statistically significant differences in the study.

Prospective randomized study to compare the effects of embryo culture performed in an incubator class 100 with HEPA VOC filter on outcome measures of ICSI cycles. Preliminary results

OBJECTIVE: Many laboratories have installed specialized incubator filtration units with the intent of enhancing air quality for embryo culture. The aim of this study is to determine whether an incubator Class 100 with HEPA VOC filter (carbon-activated) enhance the outcome measures in ICSI cycles. DESIGN: Prospective, randomized comparative study. MATERIALS AND METHODS: Prospective recruitment of all patients of age ≤ 39 years who underwent fresh ICSI cycles from September 2007 to April 2008. Fifth eight ICSI cycles were included. Embryo culture was performed either in an incubator equiped with HEPA filter (High Efficiency Particulate Air) plus carbon-activated for volatile organic compounds-HEPA VOC filter (Group I = 26) or in an identical incubator Class 100 with HEPA filter only without carbon activated (Group II = 32).Ovulation induction, laboratory techniques, embryo culture and transfer protocols were identical in both groups. Main outcome measures were number of good quality embryos transferred (≥8 cells G1/G2) and clinical pregnancy. The Student's t-test and Chi-square were applied for statistical analysis. P<.05 was considered statistically significant. RESULTS: Female age, total doses of gonadotrophins, endometrial thickness on the day of hCG administration, n° of oocytes metaphase II retrieved, n° of embryos transferred, n° of good quality embryos transferred, and clinical pregnancy were not statistically different between groups. A total of 20 transfers were performed in Group I and 28 in Group II. There were 6 cycles without transfers in Group I and 4 in Group II due to either oocyte retrieval failure or OHSS risk. Results are shown in the table 1.Table 1Patients and treatment cycles characteristicsCulture in HEPA VOC filter n=20Culture in HEPA filter n=28p valueAge32.65±3.7434.17±3.330.14Total amount of gonadotrophins (IU)1736.25±600.632011.42±789.190.19End. thickness (mm)10.39±2.1910.90±2.230.44Oocytes metaphase II (n)5.35±3.474.50±3.120.38EB transf (n)2.20±0.692.14±0.700.78EB 8C G1/G2 transf1.10±0.711.10±0.780.97Clinical pregnancy (%)55 (11/20)39 (11/28)0.38Values are expressed as mean ± SD. Open table in a new tab Values are expressed as mean ± SD. CONCLUSIONS: The preliminary data on this ongoing study has demonstrated no significant differences between the two groups in all parameters analyzed. The complete study will include 120 cycles in each group to provide 80% power in detect a difference in clinical pregnancy between the groups.

Do Urban Forests Enhance Air Quality?

There is a need for scientific understanding of how urban landscapes affect human environments regarding air, water and soil quality. This article is a review of the current science behind how urban trees influence the level of ambient air pollutants that exist in common urban airsheds. The paucity of data and directed science in this area is notable with unresolved controversy surrounding the variables used to determine the amount of air pollutants, such as particulate matter, ozone, and nitrogen and sulphur oxides, that trees can remove or add to the atmosphere. Use of percentage tree coverage, percentage urban landscape coverage, leaf area index, pollutant deposition velocity, and ambient air concentration data for New Zealand's largest city, Auckland (population 1.2 million, Statistics New Zealand 2001) provided an estimate of an annual loss of 1230 tonnes of nitrogen dioxide, 1990 tonnes of ozone and 1320 tonnes of particulate matter due to existing Auckland woodlands.

Do Urban Forests Enhance Air Quality?

There is a need for scientific understanding of how urban landscapes affect human environments regarding air, water and soil quality. This article is a review of the current science behind how urban trees influence the level of ambient air pollutants that exist in common urban airsheds. The paucity of data and directed science in this area is notable with unresolved controversy surrounding the variables used to determine the amount of air pollutants, such as particulate matter, ozone, and nitrogen and sulphur oxides, that trees can remove or add to the atmosphere. Use of percentage tree coverage, percentage urban landscape coverage, leaf area index, pollutant deposition velocity, and ambient air concentration data for New Zealand's largest city, Auckland (population 1.2 million, Statistics New Zealand 2001) provided an estimate of an annual loss of 1230 tonnes of nitrogen dioxide, 1990 tonnes of ozone and 1320 tonnes of particulate matter due to existing Auckland woodlands.

Qualitative and quantitative evaluation of MODIS satellite sensor data for regional and urban scale air quality

Advances in satellite sensors have provided new datasets for monitoring air quality at urban and regional scales. Qualitative true color images and quantitative aerosol optical depth data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the Terra satellite were compared with ground-based particulate matter data from US Environmental Protection Agency (EPA) monitoring networks covering the period from 1 April to 30 September, 2002. Using both imagery and statistical analysis, satellite data enabled the determination of the regional sources of air pollution events, the general type of pollutant (smoke, haze, dust), the intensity of the events, and their motion. Very high and very low aerosol optical depths were found to be eliminated by the algorithm used to calculate the MODIS aerosol optical depth data. Correlations of MODIS aerosol optical depth with ground-based particulate matter were better in the eastern and Midwest portion of the United States (east of 100 � W). Data were patchy and had poorer correlations in the western US, although the correlation was dependent on location. This variability is likely due to a combination of the differences between ground-based and column average datasets, regression artifacts, variability of terrain, and MODIS cloud mask and aerosol optical depth algorithms. Preliminary analysis of the algorithms indicated that aerosol optical depth measurements calculated from the sulfate-rich aerosol model may be more useful in predicting ground-based particulate matter levels, but further analysis would be required to verify the effect of the model on correlations. Overall, the use of satellite sensor data such as from MODIS has significant potential to enhance air quality monitoring over synoptic and regional scales. r 2004 Elsevier Ltd. All rights reserved.

Reformulated and alternative fuels: modeled impacts on regional air quality with special emphasis on surface ozone concentration.

The comprehensive European Air Pollution and Dispersion model system was used to estimate the impacts of the usage of reformulated and alternative fuels on regional air quality with special emphasis on surface ozone concentrations. A severe western European summer smog episode in July 1994 has been used as a reference, and the model predictions have been evaluated for this episode. A forecast simulation for the year 2005 (TREND) has been performed, including the future emission development based on the current legislation and technologies available. The results of the scenario TREND are used as a baseline for the other 2005 fuel scenarios, including fuel reformulation, fuel sulfur content, and compressed natural gas (CNG) as an alternative fuel. Compared to the year 1994, significant reductions in episode peak ozone concentrations and ozone grid hours are predicted for the TREND scenario. These reductions are even more pronounced within the investigated alternative and reformulated fuel scenarios. Especially, low sulfur fuels are appropriate for an immediate improvement in air quality, because they effect the emissions of the whole fleet. Furthermore, the simulation results indicate that the introduction of CNG vehicles would also enhance air quality with respect to ozone.

Prospective Randomized Trial of Incubator CODA Filtration Units Revealed No Effect on Outcome Parameters for IVF.

Introduction: Laboratory air quality vs. IVF success has received considerable attention. To alleviate concerns over substandard air conditions, many laboratories have installed specialized incubator filtration units (CODA, GenX, Connecticut, USA) with the intent of enhancing air quality for embryo culture. The efficacy of this approach has only been described in a single report (Mayer et al. Fertil Steril 1999;72(Suppl 1):S42). These filtration units are expensive to operate, thus it may be prudent for programs to determine whether they are effective in their own lab environments.

Methodological Issues on Developing Bypass Routes for Interstate Accidents

Incidents on freeways can cause significant disruption to traffic flows. Thus, to reduce delays, improve capacity, enhance air quality, minimize driver frustration, and improve safety along freeways, incident management programs are frequently implemented. Essential to achieving these goals are well-thought and thoroughly developed diversion routes. This paper focuses on the development and evaluation of the diversion routes used in an incident management plan for the Lexington-Fayette Urban County Government and presents some of the methodological concepts that should be considered while developing such routes. Optimization and simulation software for urban traffic signal systems were used to evaluate these routes.

Clean air standards under scrutiny again

The National Commission of Air Quality is searching for options to regulations that will be tested next year in five different regions of the country. The commission is charged with a three-year review of the Clean Air Act. It is specifically mandated to test nonregulatory alternatives for protecting and enhancing air quality. The commission will, among other things, make recommendations on policy alternatives to ambient air quality standards, especially options or modifications to the prevention of significant deterioration and nonattainment regulations. Selected so far as one of the five test regions is southern California. Other areas to be chosen must fit criteria chosen to yield the most representative range of possible problems. Among those areas chosen will likely be one with both a polluting source and a receptor, so that nonregulatory solutions to such problems as long-range transport of pollutants can be tested. The Four Corners area in the Southwest would be a likely candidate to fit this characteristic. A frost-belt city that is experiencing a slow rate of growth, like Philadelphia or Cleveland, is another category. While the commission will not question the present law, it will offer suggestions to achieve implementation of the goals of the Clean Airmore » Act. (SAC)« less