Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management.
Riza, N.A.; Sheikh, M. All-silicon carbide hybrid wireless-wired optics temperature sensor network basic design engineering for power plant gas turbines. Int. J. Optomechatronics 2010, 4, 83–91, doi:10.1080/15599611003650008.
Chang, C.Y.; Hung, S.S.; Peng, Y.F. An evaluation of the embedment of a radio frequency integrated circuit with a temperature detector in building envelopes for energy conservation. Energ. Buildings 2011, 43, 2900–2907, doi:10.1016/j.enbuild.2011.07.009.
de Vito, S.; di Palma, P.; Ambrosino, C.; Massera, E.; Burrasca, G.; Miglietta, M.L.; di Francia, G. Wireless sensor networks for distributed chemical sensing: Addressing power consumption limits with on-board intelligence. IEEE Sens. J. 2011, 11, 947–955.
Chen, J.; Li, D.L.; Du, S.F.; Wei, Y.G.; Tai, H.J. A wireless sensor network based water temperature stratification monitoring system for aquaculture of sea cucumber. Sens. Lett. 2011, 9, 1094–1100, doi:10.1166/sl.2011.1401.
Jung, Y.J.; Lee, Y.K.; Lee, D.G.; Ryu, K.H.; Nittel, S. Air Pollution Monitoring System Based on Geosensor Network. In Proceedings of the 28th Geoscience and Remote Sensing Symposium, Boston, MA, USA, 7–11 July 2008; Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA.
Kim, J.J.; Smorodinsky, S.; Lipsett, M.; Singer, B.C.; Hodgson, A.T.; Ostro, B. Traffic-related air pollution near busy roads. Amer. J. Resp. Crit. Care 2004, 170, 520–526, doi:10.1164/rccm.200403-281OC.
Künzli, N.; Tager, B. Long-term health effects of particulate and other ambient air pollution: Research can progress faster if we want it to. Environ. Health Persp. 2000, 108, 915–918, doi:10.1289/ehp.00108915.
Brauer, M.; Hoek, G.; van Vliet, P.; Meliefste, K.; Fischer, P.; Gehring, U.; Heinrich, J.; Cyrys, J.; Bellander, T.; Lewne, M.; Brunekreef, B. Estimating long-term average particulate air pollution concentrations: Application of traffic indicators and geographic information systems. Epidemiology 2003, 14, 228–239.
Baronti, P.; Pillaia, P.; Chook, V.W.C.; Chessa, S.; Gotta, A.; Hu, Y.F. Wireless sensor networks: A survey on the state of the art and the 802.15.4 and ZigBee standards. Comput. Commun. 2007, 30, 1655–1695.
English, P.; Neutra, R.; Scalf, R.; Sullivan, M.; Waller, L.; Zhu, L. Examining associations between childhood asthma and traffic flow using a geographic information system. Environ. Health Persp. 1999, 107, 761–767, doi:10.1289/ehp.99107761.
Briggs, D.J.; de Hoogh, C.; Gulliver, J.; Wills, J.; Elliott, P.; Kingham, S.; Smallbone, K. A regression-based method for mapping traffic-related air pollution: application and testing in four contrasting urban environments. Sci. Total Environ. 2000, 254, 151–167.
Gehring, U.; Cyrys, J.; Sedlmeir, G.; Brunekreef, B.; Bellander, T.; Fischer, P.; Bauer, C.P.; Reinhardt, D.; Wichmann, H.E.; Heinrich, J. Traffic-related air pollution and respiratory health during the first 2 years of life. Eur. Respir. J. 2002, 19, 690–698, doi:10.1183/09031936.02.01182001.
Pershagen, G.; Svartengren, M.; Wickman, M.; Bellander, T. Traffic-related air pollution and childhood respiratory symptoms, function and allergies. Epidemiology 2008, 19, 401–408, doi:10.1097/EDE.0b013e31816a1ce3.