scholarly journals Robust Inferential Techniques Applied to the Analysis of the Tropospheric Ozone Concentration in an Urban Area

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 277
Author(s):  
Wilmar Hernandez ◽  
Alfredo Mendez ◽  
Vicente González-Posadas ◽  
José Luis Jiménez-Martín ◽  
Iván Menes Camejo
Keyword(s):  
Air Quality ◽  
Confidence Intervals ◽  
Tropospheric Ozone ◽  
Air Quality Monitoring ◽  
Robust Methods ◽  
Time Period ◽  
Measurement Results ◽  
Robust Techniques ◽  
The City ◽  
Better Than

This paper analyzes 12 years of tropospheric ozone (O3) concentration measurements using robust techniques. The measurements were taken at an air quality monitoring station called Belisario, which is in Quito, Ecuador; the data collection time period was 1 January 2008 to 31 December 2019, and the measurements were carried out using photometric O3 analyzers. Here, the measurement results were used to build variables that represented hours, days, months, and years, and were then classified and categorized. The index of air quality (IAQ) of the city was used to make the classifications, and robust and nonrobust confidence intervals were used to make the categorizations. Furthermore, robust analysis methods were compared with classical methods, nonparametric methods, and bootstrap-based methods. The results showed that the analysis using robust methods is better than the analysis using nonrobust methods, which are not immune to the influence of extreme observations. Using all of the aforementioned methods, confidence intervals were used to both establish and quantify differences between categories of the groups of variables under study. In addition, the central tendency and variability of the O3 concentration at Belisario station were exhaustively analyzed, concluding that said concentration was stable for years, highly variable for months and hours, and slightly changing between the days of the week. Additionally, according to the criteria established by the IAQ, it was shown that in Quito, the O3 concentration levels during the study period were not harmful to human health.

scholarly journals Robust Estimation of Carbon Monoxide Measurements

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4958 ◽  
Author(s):  
Wilmar Hernandez ◽  
Alfredo Mendez
Keyword(s):  
Carbon Monoxide ◽  
Air Quality ◽  
Confidence Intervals ◽  
Research Work ◽  
Random Variable ◽  
Air Quality Monitoring ◽  
Central Tendency ◽  
Nonparametric Bootstrap ◽  
Co Concentration ◽  
Robust Statistical Methods

This paper presents a robust analysis of carbon monoxide (CO) concentration measurements conducted at the Belisario air-quality monitoring station (Quito, Ecuador). For the analysis, the data collected from 1 January 2008 to 31 December 2019 were considered. Additionally, each of the twelve years analyzed was considered as a random variable, and robust location and scale estimators were used to estimate the central tendency and dispersion of the data. Furthermore, classic, nonparametric, bootstrap, and robust confidence intervals were used to group the variables into categories. Then, differences between categories were quantified using confidence intervals and it was shown that the trend of CO concentration at the Belisario station in the last twelve years is downward. The latter was proven with the precision provided by both nonparametric and robust statistical methods. The results of the research work robustly proved that the CO concentration at Belisario station in the last twelve years is not considered a health risk, according to the criteria established by the Quito Air Quality Index.

scholarly journals Rationale For a Regional Monitoring Program of Atmospheric Air Quality in the Dnepropetrovsk Region

2021 ◽  
Vol 6 (3) ◽  
pp. 220-225
Author(s):  
S. V. Stepanov ◽  
◽  
N. I. Rublevska
Keyword(s):  
Public Health ◽  
Air Quality ◽  
Monitoring System ◽  
Phenol Formaldehyde ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Regional Monitoring ◽  
Atmospheric Air ◽  
Industrial Cities ◽  
The City

The air quality monitoring system in industrial cities is one of the systems for responding to risk factors in the public health system. The purpose of the study is, on the basis of a hygienic assessment of carcinogenic and non-carcinogenic risks from exposure to specific pollutants in the cities of Dnipro, Kamenskoye, Kryvyi Rih, to substantiate a program for regional monitoring of atmospheric air quality. Materials and methods. To achieve this goal, the results of air quality studies in the largest industrial cities of the Dnipropetrovsk region – Dnipro, Kryvyi Rih and Kamenskoe for the period 2005-2019 were analyzed in terms of phenol, formaldehyde, benzene, xylene and toluene, and carcinogenic and non-carcinogenic risks to public health were calculated in these cities. Results and discussion. According to the results of the study, individual carcinogenic risks in all three cities in terms of formaldehyde are medium, and in terms of benzene are high. The population carcinogenic risk ranges from 200-269 additional cases of cancer from exposure to formaldehyde and 3727-4426 additional cases of cancer from chronic inhalation exposure to benzene. The calculation of non-carcinogenic risks identified the priority specific air pollutants in the cities under study, as well as the main target organs. So the main systems that are influenced by the action of the studied chemicals are the central nervous system, the general development of the body and the blood system. Based on the risk assessment, it was established that it is necessary to include the Kamenskoye metro station for regional monitoring. It is necessary to include all pollutants from List A to the minimum list of investigated chemicals, and for the city of Dnipro and Kamenskoye it is additionally necessary to carry out studies of phenol, formaldehyde and toluene and in the city of Kryvyi Rih – formaldehyde and toluene. The mechanism of data processing and interaction between the subjects of monitoring has been substantiated for the timely identification of risks and the development of necessary preventive measures for risk management. Conclusion. It was found that carcinogenic and non-carcinogenic risks in industrial cities of the Dnipropetrovsk region are not acceptable. The existing monitoring system does not fully comply with the current requirements. The minimum program of the regional air quality monitoring system in the Dnipropetrovsk region has been scientifically substantiated

scholarly journals Analysis of concentration levels of particulate matter (PM10, total suspended particulates and black smoke) in the city of Zrenjanin

2010 ◽  
Vol 64 (5) ◽  
pp. 453-458 ◽  
Author(s):  
Bogdana Vujic ◽  
Dusan Milovanovic ◽  
Dejan Ubavin
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Geographical Location ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Suspended Particulates ◽  
Black Smoke ◽  
Total Suspended Particulates ◽  
The City ◽  
Concentration Levels

Air quality monitoring on the territory of AP Vojvodina was initiated in mid 90s. During the last decade of the 20th century the development of the air quality monitoring in Serbia didn?t keep up with the pace of the other countries in the region due to political isolation and severe economic crisis. Monitoring of the particular pollutants was conducted unsystematically and sporadically. Data presented in this paper were obtained on the territory of the city of Zrenjanin, which represents typical agglomeration in the region in regard to its geographical location, population, level of industry development and the presence of natural gas as energy product in the remote and domestic heating system of residential objects. Available data on the concentration levels of PM10 (particulate matter with aerodynamic diameter less than 10 ?m), TSP (total suspended particulates) and BS (black smoke) during the period of 2005-2007 (three cold and three warm seasons) have been used in this work in order to carry out analysis and comparison of the daily concentration levels of PM10, TSP and BS and their seasonal variation.

scholarly journals Relevance of Drift Components and Unit-to-Unit Variability in the Predictive Maintenance of Low-Cost Electrochemical Sensor Systems in Air Quality Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3298
Author(s):  
Georgi Tancev
Keyword(s):  
Air Quality ◽  
Anomaly Detection ◽  
Low Cost ◽  
Predictive Maintenance ◽  
Quality Monitoring ◽  
Calibration Data ◽  
Sensor Systems ◽  
Air Quality Monitoring ◽  
Measurement Results ◽  
Unsupervised Anomaly Detection

As key components of low-cost sensor systems in air quality monitoring, electrochemical gas sensors have recently received a lot of interest but suffer from unit-to-unit variability and different drift components such as aging and concept drift, depending on the calibration approach. Magnitudes of drift can vary across sensors of the same type, and uniform recalibration intervals might lead to insufficient performance for some sensors. This publication evaluates the opportunity to perform predictive maintenance solely by the use of calibration data, thereby detecting the optimal moment for recalibration and improving recalibration intervals and measurement results. Specifically, the idea is to define confidence regions around the calibration data and to monitor the relative position of incoming sensor signals during operation. The emphasis lies on four algorithms from unsupervised anomaly detection—namely, robust covariance, local outlier factor, one-class support vector machine, and isolation forest. Moreover, the behavior of unit-to-unit variability and various drift components on the performance of the algorithms is discussed by analyzing published field experiments and by performing Monte Carlo simulations based on sensing and aging models. Although unsupervised anomaly detection on calibration data can disclose the reliability of measurement results, simulation results suggest that this does not translate to every sensor system due to unfavorable arrangements of baseline drifts paired with sensitivity drift.

scholarly journals The representativeness of ground-based air quality monitoring stations: observation and recommendation from Indian cities 

2021 ◽  
Author(s):  
Arindam Roy ◽  
Satoshi Takahama ◽  
Athanasios Nenes ◽  
Sumit Sharma ◽  
Anju Goel
Keyword(s):  
Land Use ◽  
Air Quality ◽  
Premature Mortality ◽  
Quality Monitoring ◽  
Quality Data ◽  
Population Exposure ◽  
Air Quality Monitoring ◽  
The City ◽  
Indian Cities ◽  
Monitoring Stations

<div> <p>It is well established that the high level of particulate matter is a leading cause of premature mortality and disease worldwide and especially in South Asia (Global Burden of Disease Study, 2019). The ground-based air quality (AQ) monitoring stations are used to calculate economic loss, premature mortality and validate the conversed PM2.5 concentration from satellite-based Aerosol Optical Depth (AOD) data. Over India, 793 manual monitoring air quality (AQ) monitoring stations and 307 automated AQ monitoring station are presently operating under the aegis of National Air Quality Monitoring Programme and Central Pollution Control Board respectively. However, studies addressing the spatial representativeness of the data generated from the AQ monitoring stations over India are very limited and therefore, it is unclear that whether the existing stations are sufficient to reflect the average ambient AQ over different Indian cities. </p> </div><div> <p>The present study intends to classify the existing AQ monitoring stations on the basis of spatial representativeness and derive a general conceptual framework for commissioning representative AQ monitoring sites for Indian cities. The methodology involves analysis of land use, populations and air quality data for the existing air quality stations in million plus Indian cities. A case study was conducted for Pune (18.5° N, 73.8° E), a western Indian metro city with 3.15 million population (Census, 2011). Using the night-time light data and high resolution PM2.5, population exposure hotspots over Pune city were identified. It was observed that not only at the midst of the municipal area, population exposure hotspots can be identified at the peripheral region of PMC/PNMC which certainly signify the role of rapid developmental activity and urban agglomeration over Pune city. The existing air quality monitoring sites are located majorly in the pollution hotspots in the city center region and therefore installing AQ monitoring stations (co-located  with weather station) at the rapidly developing parts of the city is highly recommended. The present land use pattern and the location of existing monitoring sites suggests lack of urban background monitoring stations which indicates the gap of knowledge in monitoring the average air quality responsible of long-term health effect over Pune. The prevalence of AQ monitoring stations in the road junction points and near to metro construction works might overestimate the exposure estimate of the general population in the city.   </p> </div>

scholarly journals Prayagraj: Air Pollution Profile and Policy Recommendations

2020 ◽  
Vol 15 (3) ◽  
pp. 560-573
Author(s):  
Sugandh Kumar Choudhary
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Nitrogen Dioxide ◽  
Air Pollutants ◽  
Ambient Air ◽  
Critical Zone ◽  
Rapid Urbanization ◽  
Time Period ◽  
The City ◽  
Pollution Profile

Air pollution is the fifth leading risk factor behind theworld – wide mortality. Ever growing population size feeding industrial activity through demand channel, vehicular pollution accompanied by rapid urbanization and burning of fossil fuels pose a serious threat to clean air. Some major air pollutants under study in the city of Prayagraj are Nitrogen Dioxide (NO2), Particulate Matter (PM10) and Sulphur Dioxide (SO2). Pollution profile of the city localityi.e. Rambagh, Johnstonganj, Alopibagh, Crossing Mahalakshmi talkies and Bharat Yantra Nigam are studied. PM10 level of exposure is serious in Crossing Mahalakshmi talkiesand Alopibagh area as exposure to very high level in the range of 250 – 400 µg/m3 occurs for the longest duration of time. Alopibagh, Johnstonganj and Rambagh shows critical level of Nitrogen Dioxide indicating higher vehicular movement in these areas. Trend wise, SO2 component has spiked above 12 µg/m3 at Rambagh, Johnstonganj and Alopibagh during the onset of winters season in 2016. Similar phenomenon was seen at Bharat Yantra Nigam and Crossing Mahalakshmi talkies during winter season of 2019. Arrival of monsoon tend to lower pollutants content in the outdoor ambient air quality. Overall air quality is in critical zone at Alopibagh for 45 per cent of the time period followed by Johnstonganj. Crossing Mahalakshmi talkies and Bharat Yantra Nigamshows critical air quality for more than 60 per cent of the time period which calls for urgent action to prevent them from entering the critical zone. Overall air quality of Prayagraj is range bound with air pollutants improve during the monsoon season. However, improvement in air quality has reduced in the last two years as fall in air pollutants is less in 2018 and 2019 monsoon compared to previous two years. The findings of the paper will help the administration, municipal corporation and various stake holders of the city to take targeted measures locality wise towards pollution control depending upon pollutants concentration and exposure area – wise. It will also raise public awareness about pollutant levels in their area.

scholarly journals KAJIAN KUALITAS AMBIEN UDARA DI KOTA SEMARANG (Studi Kasus: Jalan Setiabudi Dan Jalan Anton Sujarwo)

2020 ◽  
Vol 25 (2) ◽  
pp. 148
Author(s):  
Warsiti Warsiti ◽  
Risman Risman ◽  
Ardhi Ristiawan
Keyword(s):  
Air Quality ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
The Road ◽  
Measurement Results ◽  
Road Geometry ◽  
On The Road ◽  
Motorized Vehicles ◽  
The Relationship ◽  
Road Slope

It is hoped that the study of air quality monitoring in the area around the road can provide input to the Policy Provider regarding the number of motorized vehicles and road geometry planning so that air quality continues to meet health standards. The tool used in this study is a CO meter. Data was collected for 1 week on roads in Semarang by recording the number of vehicles passing within a certain period of time on roads with various road slopes and the amount of CO levels in the air. The data from the measurement results are compiled and then analyzed, namely analyzing the relationship between the amount of CO content in the air and the number of vehicles on the road with a certain slope. From the results of the analysis, the results will be obtained how much influence the number of passing vehicles with CO levels in the air on roads with certain slopes. The resulting output is a graph of the relationship between CO levels and the number of vehicles on various road slopes. The results showed that there was an increase in the amount of CO to the number of vehicles for the variation of the road slope of 0.5%, 2% and 5%. A significant increase in the amount of CO occurred during peak hours, namely 7.00 - 8.00 and 16.00 - 17.00 hours even exceeding the established threshold of 15,000 μg / Nm3.

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