Citizens network as reference for odor impact sensors — A case study

Nuisance from gaseous emissions is evaluated depending on their nature: For known pollutants, analytical instruments provide reliable technical measurements; odors, however, have to be assessed through human sensory analysis. For impact sites, complexity is increased by the size of the relevant area and the scarcity of occurrence. Sensor systems could supplement regulated procedures with continuous indicative measurements, requiring high sensitivity and low cost to allow for close-meshed networks. This paper reports on a pilot study combining a distributed installation of temperature modulated metal oxide sensors with a human reference panel. This so-called citizens network consisted of volunteering residents from a region affected by unpleasant odors. Following considerations on data pre-treatment and validation, we found that citizen data can be used to correlate sensor reaction and odor events even several kilometers from the emission source. This is an important prerequisite for impact related calibration of distributed sensor nodes for online monitoring.