Enhanced Air Quality Research Articles

Building Better Cities: Evaluating the Effect of Circular Economy City Construction on Air Quality via a Quasi-Natural Experiment.

The resource utilization of a circular economy should reflect both economic and environmental values. Resource utility can be measured by GDP in the short term, while environmental value is challenging to measure; that is, the improvement in air quality is not effectively evaluated. In order to examine this initiative, using China's pilot cities of circular economy as a quasi-natural experiment, we construct a difference-in-difference (DID) strategy for estimation. The results demonstrate the following: (1) the pollutant emissions of pilot cities decline by 2.92 percentage points (p < 0.01) compared to unpiloted cities, (2) the policies on pilot cities more rapidly enhanced air quality for central cities and those with a low level of economic development, and (3) pilot cities significantly enhance air quality by decreasing energy consumption per unit of GDP. We provide the first empirical evidence of the effectiveness of circular economy pilot cities in improving air quality.

Enhanced air quality prediction by edge-based spatiotemporal data preprocessing

Particulate matter with a diameter less than 2.5 micrometers (PM2.5) can be considered as the most dangerous air pollutant that affects human health. In addition, technological advances, such as those involving the Internet of Things (IoT) for monitoring air quality, have made it possible to monitor air quality for a lower cost. However, missing values and noisy data make nonlinear data provided by air quality IoT sensors less reliable and more complicated than data provided by air quality monitoring stations. In this study, we propose a mixed edge-based and cloud-based framework with the final goal of PM2.5 value prediction. In order to validate the proposed approach, we evaluate the quality of predictions using both original and preprocessed data on a real-world dataset from air quality sensors distributed in Calgary, Canada. Obtained results show an average improvement of 40.18% of the prediction accuracy on Mean Absolute Percentage Error by using the proposed preprocessing technique.

An IoT enabled system for enhanced air quality monitoring and prediction on the edge

Air pollution is a major issue resulting from the excessive use of conventional energy sources in developing countries and worldwide. Particulate Matter less than 2.5 µm in diameter (PM2.5) is the most dangerous air pollutant invading the human respiratory system and causing lung and heart diseases. Therefore, innovative air pollution forecasting methods and systems are required to reduce such risk. To that end, this paper proposes an Internet of Things (IoT) enabled system for monitoring and predicting PM2.5 concentration on both edge devices and the cloud. This system employs a hybrid prediction architecture using several Machine Learning (ML) algorithms hosted by Nonlinear AutoRegression with eXogenous input (NARX). It uses the past 24 h of PM2.5, cumulated wind speed and cumulated rain hours to predict the next hour of PM2.5. This system was tested on a PC to evaluate cloud prediction and a Raspberry Pi to evaluate edge devices’ prediction. Such a system is essential, responding quickly to air pollution in remote areas with low bandwidth or no internet connection. The performance of our system was assessed using Root Mean Square Error (RMSE), Normalized Root Mean Square Error (NRMSE), coefficient of determination (R2), Index of Agreement (IA), and duration in seconds. The obtained results highlighted that NARX/LSTM achieved the highest R2 and IA and the least RMSE and NRMSE, outperforming other previously proposed deep learning hybrid algorithms. In contrast, NARX/XGBRF achieved the best balance between accuracy and speed on the Raspberry Pi.

Advanced Air Pollution Detection using IOT and Raspberry PI

Air pollution becomes more complicated nowadays in many applications. In India, many cities are affecting air pollution. This is the increasing problem day by day. Various measures are taken to calculate the air quality and more preventative measures to be taken to control air pollution. Many air quality measures are taken to overcome the pollution but till now no improvement in the air quality is observed. In this paper, an enhanced air quality detection system is introduced to find the air polluted gases present in the environment. Air quality index was sensed gases like MQ2, MQ135, MQ7, etc. and displayed each and every calculation in the LCD display. New integrated technology is introduced with the integration of IoT to overcome the pollution problem.

Impact of COVID-19 lockdown in Tamil Nadu: Benefits and challenges on environment perspective

Prior to COVID-19 lockdown in our country, the air around us was highly polluted due to emission of greenhouse gases for over centuries. Melting of glaciers and rising of the sea levels were evidenced as the alarming signs of Global warming. Environmental degradation was observed rapidly due to depletion and exploitation of natural resources like soil, water and air. But there are few changes observed in the environment after the country’s lockdown due to coronavirus pandemic. The effects of lockdown are also entwined with human and political effects such as uncontrollable public mobility, poor access to health care due to lack of sufficient medical facilities, unemployment, migrants’ crisis, starvation and prevailing poverty. However, apart from sufferings of entire country especially the people by social, economic and psychologic effects in day-to-day life, this lockdown has given to the nature the most optimistic scenarios in environment especially with enhanced air quality, cleaner water and undisturbed pristine forest. The present review brings out the actual picture of the eco-processes that reduced man-made pollution in air and water as well as disposal of domestic or biological waste along with societal implications after imposing lockdown in the state of Tamil Nadu.

Enhanced air quality modelling through AUSTAL2000 model in Milan urban area

Atmospheric dispersion models are a useful tools to assess air quality and emission source contributions in urban areas. Eulerian chemical and transport models (CTMs) can assess the regional background, that is the baseline level in the region of the city, and the urban background, that is the increment of concentration due to the emissions of the city, but they are not able to properly assess the very local contribution of emission sources at pollution hotspots within the city, because of their relatively large grid step. For the assessment of local sources’ contribution, Lagrangian dispersion models can be profitably used, especially when high spatial resolution modelling is required. Actually, Lagrangian models rely on a more realistic spatialization of urban emissions, unevenly distributed because of the road network layout (for traffic emissions) and of the built environment structure (for space heating emissions); additionally, Lagrangian models also account for wind field modifications induced by buildings. In this work, air quality modelling results for fine particles (PM2.5) in the city centre of Milan obtained by means of the AUSTAL2000 Lagrangian model are compared with those of CAMx Eulerian model. Model simulations where performed for a 1.7x1.7 km2 area in Milan and focused on three receptor points selected in order to represent sites with both different features in terms of the surrounding built environment and different exposure to the local emission sources. Namely, the receptors correspond to a green area, to a residential and shopping area near Milan main square, and to a congested crossroad on the inner ring road of the city centre. Comparison results show that the outcome of the Eulerian model at the local scale is only representative of a background level, similar to Lagrangian model’s outcome for the green area receptor, but fails to reproduce concentration gradients and hot-spots, driven by local sources’ emissions.

Volatile organic compounds and good laboratory practices in the in vitro fertilization laboratory: the important parameters for successful outcome in extended culture

This study aims to describe the role of implementing good laboratory practices to improve in vitro fertilization (IVF) outcomes which are of great interest for practitioners dealing with infertility. Certain modifications were introduced in May 2015 in our IVF laboratory like high-efficiency particulate air CODA system, steel furniture instead of wooden, use of new disinfectants like oosafe, and restriction of personnel entry along with avoidance of cosmetics like perfume to improve pregnancy rates. Volatile organic compound (VOC) meter reading was monitored at two time points and five different places in the laboratory to compare the embryonic development parameters before (group A: July 2014-April 2015) and after (group B: July 2015-April 2016) remodeling. The IVF outcomes from 1036cycles were associated in this study. Reduction in VOC meter readings, enhanced air quality, improvement in blastocyst formation rate, implantation, and clinical pregnancy rate were observed in the laboratory after implementation of new facilities. Results illustrated that the attention must be focused on potential hazards which expose laboratories to elevated VOC levels. Blastocyst formation rate increased around 18%. Implantation rate, clinical pregnancy rate, and live birth rate increased by around 11, 10, and 8%, respectively. In conclusion, with proper engineering and material selection, we have been able to reduce chemical contamination and adverse effects on culture with optimized IVF results. None.

Changing culture conditions. blastocyst ploidy following standard incubation and uninterrupted culture in the embryoscope (ES)

To determine the effect of uninterrupted culture with minimal light exposure, versus standard incubation of embryos in a 5.5% CO2, 5% O2 environment, on the euploid:aneuploid ratio of blastocysts, determined by trophectoderm biopsy. Patients attended for preimplantation aneuploidy screening of their blastocysts. Between November 2009 and April 2011 embryos were cultured in low O2 incubators (Galaxy, SLS, UK) and observed daily. Between April 2011 and April 2012, embryos were cultured uninterrupted in the ES (Unisense, Denmark) and observed using time-lapse images. This study aimed to compare the euploid:aneuploid ratio of embryos developed in these contrasting incubators. Trophectoderm biopsy was performed on 126 blastocysts at CARE Fertility in Manchester, England. Blastocyst chromosome constitution was determined by array comparative genomic hybridisation for 15 patients and single nucleotide polymorphism microarray testing for 18 patients. The euploid:aneuploid ratio from each incubation condition and the proportion of embryos suitable for biopsy were compared using Fisher's Exact Test. 304 embryos were cultured for 33 patients. 41.9% and 41.1% of embryos cultured in the standard and ES incubators respectively underwent biopsy and obtained a screening result. No significant difference in the proportion of euploid and aneuploid blastocysts was observed following standard or ES incubation (P=0.5884,n=52 standard,n=74 ES). Average patient age was 37.1±3.98 and 37.5±4.24 respectively for standard and ES culture. The change from single observation standard incubation to uninterrupted culture has not significantly altered the euploid:aneuploid ratio or the proportion of blastocysts suitable for biopsy. Therefore, the uninterrupted culture, enhanced air quality and decreased temperature fluctuations of the ES appear not to affect chromosome segregation within blastocysts. As patient numbers increase, the analysis will be updated.

An assessment of ozone concentrations within and near the Lake Tahoe Air Basin

Abstract The Lake Tahoe Atmospheric Deposition Study (LTADS) was conducted by the Air Resources Board of the State of California (CARB) primarily to generate refined estimates of the atmospheric deposition of nitrogen, phosphorous, and particulate matter directly to Lake Tahoe, which straddles the border between the states of California and Nevada near Reno, Nevada. The enhanced air quality monitoring during LTADS also included ozone measurements, which yielded additional insights into atmospheric processes and the role of transport in determining ozone concentrations within the Lake Tahoe Air Basin. The Lake Tahoe Air Basin is located generally downwind of air basins with major emissions of ozone precursors (e.g., VOCs, NOx), capable of generating significant ozone concentrations. Furthermore, vegetation on the western slope of the Sierra Nevada contribute biogenic organic compounds to the air mass. Ozone concentrations within the Tahoe Basin infrequently exceed the local 1-h threshold set to protect forest health (0.08 ppm) and the California 8-h ambient air quality standard (0.070 ppm). A concern then is the potential contribution of regional emission sources to the ozone concentrations observed in the Tahoe Basin. The ozone data collected during LTADS helped to better characterize the relative contribution of local and regional pollution sources to ozone air quality within the Tahoe Basin. The data indicate potential 1- or 2-day intact transport on rare occasions but generally the mixing of the atmosphere over the Sierra Nevada disperses the anthropogenic ozone throughout the boundary layer, which is generally more than a kilometer or two deep during the day. The data analysis indicates that emissions from upwind air basins add to the atmospheric burden of ozone concentrations, raising the regional concentrations in the Sierra Nevada. Given the large background and upwind enhancements relative to the ambient air quality standards, the local contribution does not need to be large to contribute to exceedances of an ozone air quality standard. This information can be used to refine hypotheses about the relative role of local and regional sources of air pollution impacting the Tahoe Basin. Ultimately, the improved understanding of air quality within the Tahoe Basin will guide actions in pollution control plans designed to protect public health and welfare (e.g., visibility, forest health) within this unique alpine setting.

Assessing ‘carbon balance’ of intelligent transport schemes

This paper considers how carbon costs and savings can be estimated and used as a tool, in a similar manner to the standard financial assessment tools, when assessing intelligent transport systems (ITS) schemes. This is a novel approach and one that may provide useful insights when considering investments in transport systems, especially in the light of climate change and rising energy costs. The scope and application of ITS is too broad to be considered in its entirety in one paper, so this paper considers one example—the M25 junctions 15 to 16 variable mandatory speed limit (VMSL) scheme—as a case study to determine both the carbon dioxide (CO2) costs and benefits over the life of the project. ITS can be used to reduce harmful emissions, contributing to enhanced air quality and reduced effects on climate change from CO2. The CO2 produced when constructing, operating and eventually decommissioning these schemes is, however, often overlooked. This paper considers the balance in carbon use between the building and operating of ITS-based traffic congestion management schemes and the resultant reduction in emissions from traffic. While the calculations relate to the specific example (M25 VMSL), the principals can be adopted, and further refined, for other ITS schemes.

Building-integrated solar photovoltaic systems—a hybrid solar cooled ventilation technique for hot climate applications

The paper presents two low-cost photovoltaic utilization schemes (1–50 kW) for ventilation and air conditioning loads. Both schemes can be controlled by novel dynamic on-line power tracking regulator. This ensures maximum power utilization and energy efficiency under varying conditions of solar insolation levels. The system could be used to conserve electric energy through the decrease of electric demand particularly in developing countries. In addition, the system offers benefits in other areas such as indoor enhanced air quality.