Urban Air Pollution Alert Service for Smart Cities

With the advent of small, energy-efficient, interconnected and cheap air pollution sensors, communities all over the world have begun to drive forward the expansion of city-wide sensor networks in order to get a holistic picture of the air pollution level that the citizens are exposed to in their daily life. Unfortunately, the resulting insights about the current air quality need to be actively queried by the citizens, leading to situations in which the citizen is exposed to a high air pollution without being aware of it. In this article, we introduce a context-aware air pollution monitoring and alert service that proactively notifies citizens via mobile devices about highly relevant air quality information once they enter an area with an air pollution that exceeds a user-defined threshold. The service continuously determines the concentration of particulate matter throughout a given urban area, detects closed areas with a high air pollution and shares this information with the citizen's mobile devices which are in turn responsible to regularly compare a citizen's position against the areas of poor air quality. As a proof of concept, we prototypically implemented and evaluated the service by means of real world measurements taken on consecutive days within an urban area in New Zealand.