We will mount sensors on pedestrians and cyclists to monitor their exposure to pollution from transport. This will be an addition to the TIME-EACM project, which is about to use Cambridge City as a test bed for a variety of ways to gather data about traffic flow, and is writing middleware to analyse the data in real time.The initial part of the study will be to confront the technical challenges associated with sensors that need to be highly portable. Sensor technologies are now advancing to the point where parts per billion sensitivities are becoming achievable in small low power devices for species relevant to local air quality including ozone, nitrogen dioxide and a range of hydrocarbons. The challenge will be to link such sensors to effective mobile systems to broadcast data back to central points for analysis and presentation, and to locate their wearers sufficiently accurately. The TIME-EACM project will log and store data and integrate databases with information flow from its sensors, and the data stream from the pervasive environmental sensors will be added to this. The TIME-EACM middleware will be compatible with data on pollution from pervasive environmental sensors. All data will be time-stamped and location-stamped and correlated with TIME-EACM data on traffic flow.