{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T05:04:55Z","timestamp":1787029495072,"version":"3.56.0"},"reference-count":32,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2019,8,2]],"date-time":"2019-08-02T00:00:00Z","timestamp":1564704000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006595","name":"Unitatea Executiva pentru Finantarea Invatamantului Superior, a Cercetarii, Dezvoltarii si Inovarii","doi-asserted-by":"publisher","award":["PN-III-P1-1.2-PCCDI-2017-0272"],"award-info":[{"award-number":["PN-III-P1-1.2-PCCDI-2017-0272"]}],"id":[{"id":"10.13039\/501100006595","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Air pollution is a major factor in global heating and an increasing focus is centered on solving this problem. Urban communities take advantage of Information Technology (IT) and communications technologies in order to improve the control of environmental emissions and sound pollution. The aim is to mitigate health threatening risks and to raise awareness in relation to the effects of air pollution exposure. This paper investigates the key issues of a real-time pollution monitoring system, including the sensors, Internet of Things (IoT) communication protocols, and acquisition and transmission of data through communication channels, as well as data security and consistency. Security is a major focus in the proposed IoT solution. All other components of the system revolve around security. The bill of the materials and communications protocols necessary for the designing, development, and deployment of the IoT solution are part of this paper, as well as the security challenges. The paper\u2019s proof of concept (PoC) addresses IoT security challenges within the communication channels between IoT gateways and the cloud infrastructure where data are transmitted to. The security implementations adhere to existing guidelines, best practices, and standards, ensuring a reliable and robust solution. In addition, the solution is able to interpret and analyze the collected data by using predictive analytics to create pollution maps. Those maps are used to implement real-time countermeasures, such as traffic diversion in a major city, to reduce concentrations of air pollutants by using existing data collected over a year. Once integrated with traffic management systems\u2014cameras monitoring and traffic lights\u2014this solution would reduce vehicle pollution by dynamically offering alternate routes or even enforcing re-routing when pollution thresholds are reached.<\/jats:p>","DOI":"10.3390\/s19153401","type":"journal-article","created":{"date-parts":[[2019,8,2]],"date-time":"2019-08-02T11:58:16Z","timestamp":1564747096000},"page":"3401","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":99,"title":["IoT Solution for Smart Cities\u2019 Pollution Monitoring and the Security Challenges"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9316-7739","authenticated-orcid":false,"given":"Cristian","family":"Toma","sequence":"first","affiliation":[{"name":"Department of Economic Informatics and Cybernetics, Faculty of Cybernetics, Statistics and Economic Informatics, Bucharest University of Economic Studies, 010552 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrei","family":"Alexandru","sequence":"additional","affiliation":[{"name":"Department of Economic Informatics and Cybernetics, Faculty of Cybernetics, Statistics and Economic Informatics, Bucharest University of Economic Studies, 010552 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8296-8389","authenticated-orcid":false,"given":"Marius","family":"Popa","sequence":"additional","affiliation":[{"name":"Department of Economic Informatics and Cybernetics, Faculty of Cybernetics, Statistics and Economic Informatics, Bucharest University of Economic Studies, 010552 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alin","family":"Zamfiroiu","sequence":"additional","affiliation":[{"name":"Department of Economic Informatics and Cybernetics, Faculty of Cybernetics, Statistics and Economic Informatics, Bucharest University of Economic Studies, 010552 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,8,2]]},"reference":[{"key":"ref_1","unstructured":"(2018, April 02). World Health Organization: Exposure to Ambient Air Pollution from Particulate Matter for 2016. Available online: https:\/\/www.who.int\/airpollution\/data\/AAP_exposure_Apr2018_final.pdf?ua=1."},{"key":"ref_2","unstructured":"(2019, July 31). World Health Organization\u2013Interactive Map of the Air Pollution (Using Estimate Models). Available online: https:\/\/www.who.int\/airpollution\/data\/en\/."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Johnston, S.J., Basford, P.J., Bulot, F.M.J., Apetroaie-Cristea, M., Easton, N.H.C., Davenport, C., Foster, G.L., Loxham, M., Morris, A.K.R., and Cox, S.J. (2019). City Scale Particulate Matter Monitoring Using LoRaWAN Based Air Quality IoT Devices. Sensors, 19.","DOI":"10.3390\/s19010209"},{"key":"ref_4","first-page":"65","article-title":"Wireless Internet of Things-Based Air Quality Device for Smart Pollution Monitoring","volume":"9","author":"Zakaria","year":"2018","journal-title":"Int. J. Adv. Comput. Sci. Appl."},{"key":"ref_5","unstructured":"Shahriar, A.S., Jayed, I.A., Madmudul, H.M., Monsur, R.M.N., Nishako, C., and Nafiz, I.M. (2018). Design and Development of a Low-Cost IoT based Environmental Pollution Monitoring System. Int. Conf. Electr. Eng. Inf. Commun. Technol., 651\u2013655."},{"key":"ref_6","unstructured":"Walelign, A.T., and Rutvik, M. (2018, January 20\u201321). Air pollution monitoring and prediction using IoT. Proceedings of the 2018 Second International Conference on Inventive Communication and Computational Technologies (ICICCT), Coimbatore, India."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Marques, G., and Pitarma, R. (2019). A Cost-Effective Air Quality Supervision Solution for Enhanced Living Environments through the Internet of Things. Electronics, 8.","DOI":"10.3390\/electronics8020170"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Setiawan, F.N., and Kustiawan, I. (2017, January 16). IoT based Air Quality Monitoring. Proceedings of the 2018 IOP Conference Series: Materials Science and Engineering, Bandung, Indonesia.","DOI":"10.1088\/1757-899X\/384\/1\/012008"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1007\/s10661-018-6914-x","article-title":"Real-time water quality monitoring using Internet of Things in SCADA","volume":"190","author":"Saravanan","year":"2018","journal-title":"Environ. Monit. Assess."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/j.future.2017.09.082","article-title":"Efficient IoT-based sensor BIG Data collection-processing and analysis in Smart Buildings","volume":"82","author":"Plageras","year":"2018","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Luo, L., Zhang, Y., Pearson, B., Ling, Z., Yu, H., and Fu, Z. (2018). On the Security and Data Integrity of Low-Cost Sensor Networks for Air Quality Monitoring. Sensors, 18.","DOI":"10.3390\/s18124451"},{"key":"ref_12","unstructured":"(2019, July 31). DosiTracker. Available online: https:\/\/dositracker.ro\/en\/home\/."},{"key":"ref_13","unstructured":"(2019, July 31). uRADMonitor Alba Iulia. Available online: https:\/\/www.uradmonitor.com\/alba."},{"key":"ref_14","unstructured":"(2019, July 31). Alba Iulia Smart City. Available online: https:\/\/albaiuliasmartcity.ro\/proiect\/uradmonitor\/."},{"key":"ref_15","unstructured":"O.A.S.I.S. Standard (2019, July 31). MQTT Version 3.1.1. Available online: http:\/\/docs.oasis-open.org\/mqtt\/mqtt\/v3.1.1\/os\/mqtt-v3.1.1-os.pdf."},{"key":"ref_16","first-page":"1","article-title":"Algorithms for efficient digital media transmission over IoT and cloud networking","volume":"5","author":"Stergiou","year":"2018","journal-title":"J. Multimed. Inf. Syst."},{"key":"ref_17","unstructured":"(2014, May 28). MQTT and the NIST Cybersecurity Framework Version 1.0, OASUS Committee Note 01. Available online: http:\/\/docs.oasis-open.org\/mqtt\/mqtt-nist-cybersecurity\/v1.0\/mqtt-nist-cybersecurity-v1.0.html."},{"key":"ref_18","unstructured":"(2019, July 31). NIST Cybersecurity Framework, Available online: http:\/\/www.nist.gov\/cyberframework."},{"key":"ref_19","unstructured":"(2019, July 31). National Vulnerability Database, Available online: https:\/\/nvd.nist.gov\/."},{"key":"ref_20","unstructured":"(2019, July 31). MQTT Security Fundamentals. Available online: https:\/\/www.hivemq.com\/mqtt-security-fundamentals."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Wu, X., and Li, N. (2018, January 23). Improvements of MQTT Retain Message Storage Mechanism. Proceedings of the 2018 2nd IEEE Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC), Xi\u2019an, China.","DOI":"10.1109\/IMCEC.2018.8469192"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Park, J., Yun, S., Kim, H., and Kim, W. (2017, January 18\u201320). Emergent-MQTT over SDN. Proceedings of the 2017 International Conference on Information and Communication Technology Convergence (ICTC), Jeju Island, Korea.","DOI":"10.1109\/ICTC.2017.8190805"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Andy, S., Rahardjo, B., and Hanindhito, B. (2017, January 19\u201321). Attack scenarios and security analysis of MQTT communication protocol in IoT system. Proceedings of the 2017 4th International Conference on Electrical Engineering, Computer Science and Informatics (EECSI), Yogyakarta, Indonesia.","DOI":"10.1109\/EECSI.2017.8239179"},{"key":"ref_24","unstructured":"MITRE Corporation (2019, July 31). Common Vulnerabilities and Exposures. Available online: https:\/\/cve.mitre.org\/."},{"key":"ref_25","unstructured":"(2019, July 31). OWASP Internet of Things Projects. Available online: https:\/\/www.owasp.org\/index.php\/OWASP_Internet_of_Things_Project."},{"key":"ref_26","unstructured":"Boja, C., and Zurini, M. (2018, January 17\u201320). IoT security architecture based on device fingerprinting. Proceedings of the 17th International Conference on Informatics in Economy (IE 2018) Education, Research & Business Technologies, Iasi, Romania."},{"key":"ref_27","unstructured":"Keogh, E., and Lin, J. (2019, July 31). Symbolic Aggregate Approximation Resources. Available online: http:\/\/www.cs.ucr.edu\/~eamonn\/SAX.htm."},{"key":"ref_28","unstructured":"Keogh, E., Lin, J., and Fu, A. (2005, January 27\u201330). HOT SAX: Efficiently Finding the Most Unusual Time Series Subsequence. Proceedings of the 5th IEEE International Conference on Data Mining (ICDM 2005), Houston, TX, USA."},{"key":"ref_29","first-page":"77","article-title":"Advanced Media-based Smart Big Data on Intelligent Cloud Systems","volume":"4","author":"Stergiou","year":"2018","journal-title":"IEEE Trans. Sustain. Comput."},{"key":"ref_30","unstructured":"(2019, July 31). Oracle Java Card Boosts Security for IoT Devices at the Edge. Available online: https:\/\/www.oracle.com\/corporate\/pressrelease\/oracle-java-card-boosts-security-011619.html."},{"key":"ref_31","unstructured":"(2019, July 31). World Most Polluted Cities in 2018\u2013AirVisual Project. Available online: https:\/\/www.airvisual.com\/world-most-polluted-cities?continent=59af92ac3e70001c1bd78e52&country=zk4LhMNzkk6ky46az&state=&page=1&perPage=50&cities."},{"key":"ref_32","unstructured":"(2019, July 31). TomTom Vehicles Transportation Traffic Congestion index in 2018. 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